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  Subjects -> METEOROLOGY (Total: 112 journals)
Showing 1 - 36 of 36 Journals sorted alphabetically
Acta Meteorologica Sinica     Hybrid Journal   (Followers: 3)
Advances in Atmospheric Sciences     Hybrid Journal   (Followers: 43)
Advances in Climate Change Research     Open Access   (Followers: 31)
Advances in Meteorology     Open Access   (Followers: 24)
Advances in Statistical Climatology, Meteorology and Oceanography     Open Access   (Followers: 7)
Aeolian Research     Hybrid Journal   (Followers: 6)
Agricultural and Forest Meteorology     Hybrid Journal   (Followers: 18)
American Journal of Climate Change     Open Access   (Followers: 31)
Atmósfera     Open Access   (Followers: 3)
Atmosphere     Open Access   (Followers: 26)
Atmosphere-Ocean     Full-text available via subscription   (Followers: 15)
Atmospheric and Oceanic Science Letters     Open Access   (Followers: 11)
Atmospheric Chemistry and Physics (ACP)     Open Access   (Followers: 48)
Atmospheric Chemistry and Physics Discussions (ACPD)     Open Access   (Followers: 15)
Atmospheric Environment     Hybrid Journal   (Followers: 73)
Atmospheric Environment : X     Open Access   (Followers: 3)
Atmospheric Research     Hybrid Journal   (Followers: 69)
Atmospheric Science Letters     Open Access   (Followers: 36)
Boundary-Layer Meteorology     Hybrid Journal   (Followers: 31)
Bulletin of Atmospheric Science and Technology     Hybrid Journal   (Followers: 1)
Bulletin of the American Meteorological Society     Open Access   (Followers: 51)
Carbon Balance and Management     Open Access   (Followers: 4)
Change and Adaptation in Socio-Ecological Systems     Open Access   (Followers: 5)
Ciencia, Ambiente y Clima     Open Access   (Followers: 3)
Climate     Open Access   (Followers: 6)
Climate and Energy     Full-text available via subscription   (Followers: 4)
Climate Change Economics     Hybrid Journal   (Followers: 25)
Climate Change Research Letters     Open Access   (Followers: 7)
Climate Change Responses     Open Access   (Followers: 12)
Climate Dynamics     Hybrid Journal   (Followers: 44)
Climate of the Past (CP)     Open Access   (Followers: 5)
Climate of the Past Discussions (CPD)     Open Access  
Climate Policy     Hybrid Journal   (Followers: 44)
Climate Research     Hybrid Journal   (Followers: 6)
Climate Resilience and Sustainability     Open Access   (Followers: 13)
Climate Risk Management     Open Access   (Followers: 6)
Climate Services     Open Access   (Followers: 3)
Climate Summary of South Africa     Full-text available via subscription   (Followers: 2)
Climatic Change     Open Access   (Followers: 66)
Current Climate Change Reports     Hybrid Journal   (Followers: 8)
Developments in Atmospheric Science     Full-text available via subscription   (Followers: 28)
Dynamics and Statistics of the Climate System     Open Access   (Followers: 5)
Dynamics of Atmospheres and Oceans     Hybrid Journal   (Followers: 19)
Earth Perspectives - Transdisciplinarity Enabled     Open Access  
Economics of Disasters and Climate Change     Hybrid Journal   (Followers: 3)
Energy & Environment     Hybrid Journal   (Followers: 24)
Environmental and Climate Technologies     Open Access   (Followers: 4)
Environmental Dynamics and Global Climate Change     Open Access   (Followers: 8)
Frontiers in Climate     Open Access   (Followers: 3)
GeoHazards     Open Access   (Followers: 2)
Global Meteorology     Open Access   (Followers: 17)
International Journal of Atmospheric Sciences     Open Access   (Followers: 22)
International Journal of Biometeorology     Hybrid Journal   (Followers: 1)
International Journal of Climate Change Strategies and Management     Hybrid Journal   (Followers: 22)
International Journal of Climatology     Hybrid Journal   (Followers: 31)
International Journal of Environment and Climate Change     Open Access   (Followers: 5)
International Journal of Image and Data Fusion     Hybrid Journal   (Followers: 2)
Journal of Agricultural Meteorology     Open Access  
Journal of Applied Meteorology and Climatology     Hybrid Journal   (Followers: 35)
Journal of Atmospheric and Oceanic Technology     Hybrid Journal   (Followers: 34)
Journal of Atmospheric and Solar-Terrestrial Physics     Hybrid Journal   (Followers: 198)
Journal of Atmospheric Chemistry     Hybrid Journal   (Followers: 21)
Journal of Climate     Hybrid Journal   (Followers: 54)
Journal of Climate Change     Full-text available via subscription   (Followers: 3)
Journal of Climatology     Open Access   (Followers: 3)
Journal of Hydrology and Meteorology     Open Access   (Followers: 29)
Journal of Hydrometeorology     Hybrid Journal   (Followers: 11)
Journal of Integrative Environmental Sciences     Hybrid Journal   (Followers: 4)
Journal of Meteorological Research     Full-text available via subscription   (Followers: 1)
Journal of Meteorology and Climate Science     Full-text available via subscription   (Followers: 14)
Journal of Space Weather and Space Climate     Open Access   (Followers: 27)
Journal of the Atmospheric Sciences     Hybrid Journal   (Followers: 81)
Journal of the Meteorological Society of Japan     Partially Free   (Followers: 6)
Journal of Weather Modification     Full-text available via subscription   (Followers: 2)
Large Marine Ecosystems     Full-text available via subscription   (Followers: 1)
Mathematics of Climate and Weather Forecasting     Open Access   (Followers: 6)
Mediterranean Marine Science     Open Access   (Followers: 1)
Meteorologica     Open Access   (Followers: 2)
Meteorological Applications     Hybrid Journal   (Followers: 4)
Meteorological Monographs     Hybrid Journal   (Followers: 2)
Meteorologische Zeitschrift     Full-text available via subscription   (Followers: 3)
Meteorology and Atmospheric Physics     Hybrid Journal   (Followers: 26)
Mètode Science Studies Journal : Annual Review     Open Access  
Michigan Journal of Sustainability     Open Access   (Followers: 1)
Modeling Earth Systems and Environment     Hybrid Journal   (Followers: 1)
Monthly Notices of the Royal Astronomical Society     Hybrid Journal   (Followers: 13)
Monthly Weather Review     Hybrid Journal   (Followers: 34)
Nature Climate Change     Full-text available via subscription   (Followers: 134)
Nature Reports Climate Change     Full-text available via subscription   (Followers: 37)
Nīvār     Open Access  
npj Climate and Atmospheric Science     Open Access   (Followers: 3)
Open Atmospheric Science Journal     Open Access   (Followers: 2)
Open Journal of Modern Hydrology     Open Access   (Followers: 6)
Revista Brasileira de Meteorologia     Open Access  
Revista Iberoamericana de Bioeconomía y Cambio Climático     Open Access  
Russian Meteorology and Hydrology     Hybrid Journal   (Followers: 3)
Space Weather     Full-text available via subscription   (Followers: 25)
Studia Geophysica et Geodaetica     Hybrid Journal  
Tellus A     Open Access   (Followers: 22)
Tellus B     Open Access   (Followers: 21)
The Cryosphere (TC)     Open Access   (Followers: 5)
The Cryosphere Discussions (TCD)     Open Access   (Followers: 4)
The Quarterly Journal of the Royal Meteorological Society     Hybrid Journal   (Followers: 27)
Theoretical and Applied Climatology     Hybrid Journal   (Followers: 13)
Tropical Cyclone Research and Review     Open Access   (Followers: 1)
Urban Climate     Hybrid Journal   (Followers: 4)
Weather     Hybrid Journal   (Followers: 19)
Weather and Climate Dynamics     Open Access  
Weather and Climate Extremes     Open Access   (Followers: 16)
Weather and Forecasting     Hybrid Journal   (Followers: 28)
Weatherwise     Hybrid Journal   (Followers: 4)
气候与环境研究     Full-text available via subscription   (Followers: 1)

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Atmosphere
Number of Followers: 26  

  This is an Open Access Journal Open Access journal
ISSN (Online) 2073-4433
Published by MDPI Homepage  [233 journals]
  • Atmosphere, Vol. 12, Pages 525: The Signal to Noise Ratio and the
           Completeness Magnitude: The Effect of the COVID-19 Lockdown

    • Authors: Cataldo Godano, Vincenzo Convertito, Nicola Alessandro Pino
      First page: 525
      Abstract: We analyse the earthquakes catalogues for Italy, South California, and Greece across the COVID-19 lockdown period for each country. The results for Italy and Greece show that, even if the reduction of the signal to noise ratio has improved the earthquake detection capability, the completeness magnitude remains substantially unchanged, making the improved detection capability ineffective from the statistical point of view. A slight reduction (0.2) of the completeness magnitude is observed for South California, likely related to the relatively higher number of seismic stations located close to urban areas. Our findings suggest that—given the present configuration of the seismic network considered here—only an important decrease in the station spacing can produce a significant decrease of the completeness magnitude.
      Citation: Atmosphere
      PubDate: 2021-04-21
      DOI: 10.3390/atmos12050525
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 526: Size-Segregated Atmospheric Humic-Like
           Substances (HULIS) in Shanghai: Abundance, Seasonal Variation, and Source
           Identification

    • Authors: Tianming Sun, Rui Li, Ya Meng, Yu Han, Hanyun Cheng, Hongbo Fu
      First page: 526
      Abstract: Humic-like substances (HULIS) are of great interest due to their optical and chemical characteristics. In this study, a total of 180 samples of atmospheric particulate matter (PM) of different sizes were collected from summer 2018 to spring 2019, in order to analyze the size distribution, to investigate the seasonal variation and then to identify the key sources of HULIS. The annual mean concentration of HULIS in the total suspended particulates reached 5.12 ± 1.42 μg/m3. The HULIS concentration was extremely higher in winter (8.35 ± 2.06 μg/m3) than in autumn (4.88 ± 0.95 μg/m3), in summer (3.62 ± 1.68 μg/m3) and in spring (3.36 ± 0.99 μg/m3). The average annual ratio of water-soluble organic carbon (WSOC) to OC and the ratio of HULIS to WSOC reached 0.546 ± 0.092 and 0.56 ± 0.06, respectively. Throughout the whole year, the size distributions of WSOC and HULIS-C were relatively smooth. The peaks of WSOC appeared at 1.8~3.2 μm and 0.56~1.0 μm, while the peaks of HULIS-C were located at 3.2~5.6 μm, 1.0~1.8 μm and 0.18~0.32 μm. The distribution of the HULIS particle mode was similar in spring, summer and autumn, while there was a lower proportion of the coarse mode and a higher proportion of the condensation mode in winter. By using the comprehensive analysis of principal component analysis (PCA), air mass backward trajectories (AMBTs) and fire point maps, key sources of WSOC and HULIS in Shanghai were identified as biomass combustion (48.42%), coal combustion (17.49%), secondary formation (16.07%) and vehicle exhaust (5.37%). The remaining part might be contributed by crustal dust sources, marine sources and/or other possible sources. This study provides new insight into the characteristics and size distribution of HULIS in Shanghai, thereby providing a practical base for further modeling.
      Citation: Atmosphere
      PubDate: 2021-04-21
      DOI: 10.3390/atmos12050526
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 527: Evaluation of the Perspective of
           ERA-Interim and ERA5 Reanalyses for Calculation of Drought Indicators for
           Uzbekistan

    • Authors: Natella Rakhmatova, Mikhail Arushanov, Lyudmila Shardakova, Bakhriddin Nishonov, Raisa Taryannikova, Valeriya Rakhmatova, Dmitry A. Belikov
      First page: 527
      Abstract: The arid and semiarid regions of Uzbekistan are sensitive and vulnerable to climate change. However, the sparse and very unevenly distributed meteorological stations within the region provide limited data for studying the region’s climate variation. The aim of this work was to evaluate the performance of the European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA)-Interim and ERA5 products for the fields of near-surface temperature, humidity, and precipitation over Uzbekistan from 1981 to 2018 using observations from 74 meteorological stations. Major results suggested that the reanalysis datasets match well with most of the observed climate records, especially in the plain areas. While ERA5, with a high spatial resolution of 0.1°, is able more accurately reproduce mountain ranges and valleys. Compared to ERA-Interim, the climatological biases in temperature, humidity, and total precipitation from ERA5 are clearly reduced, and the representation of inter-annual variability is improved over most regions of Uzbekistan. Both reanalyses show a high level of agreement with observations on the standardized precipitation evaporation index (SPEI) with a correlation coefficient of 0.7–0.8.Although both of these ECMWF products can be successfully implemented for the calculation of atmospheric drought indicators for Uzbekistan and adjacent regions of Central Asia, the newer and advanced ERA5 is preferred.
      Citation: Atmosphere
      PubDate: 2021-04-21
      DOI: 10.3390/atmos12050527
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 528: Exploring the Relationships of Atmospheric
           Water Vapor Contents and Different Land Surfaces in a Complex Terrain Area
           by Using Doppler Radar

    • Authors: Hezhen Lou, Jun Zhang, Shengtian Yang, Mingyong Cai, Xiaoyu Ren, Ya Luo, Chaojun Li
      First page: 528
      Abstract: Changes in atmospheric water vapor mainly occur in the atmospheric boundary layer. However, due to many factors, such as orography and ground thermal dynamic conditions, the change trends and transformation law of atmospheric water vapor contents above different surfaces are still unclear. In this work, a Doppler weather radar with high spatial-temporal resolution was used to monitor the variations and transformations of water vapor contents over different land surfaces for two years. The results show that the atmospheric water vapor content shows a very good positive correlation with elevation at altitudes between 600 m and 1200 m, while different land surfaces have delicate impacts on atmospheric water vapor contents, such as extreme values appearing above impervious urban surfaces, uniform distributions appearing over water body and vegetated surfaces being wet but avoiding extreme conditions. Compared with previous studies, the results and conclusions of this study are mainly derived from accurate direct observations based on high-resolution radar. Identifying the distribution and transformation of water vapor over different surfaces can enhance our understanding of the movement and variation of atmospheric water vapor over complex terrain and different land surfaces, and improve the planning and construction capacity of different surfaces, such that humankind can mitigate the severe disasters caused by drastic changes in atmospheric water vapor.
      Citation: Atmosphere
      PubDate: 2021-04-21
      DOI: 10.3390/atmos12050528
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 529: High Resolution Mapping of PM2.5
           Concentrations in Paris (France) Using Mobile Pollutrack Sensors Network
           in 2020

    • Authors: Jean-Baptiste Renard, Christophe Marchand
      First page: 529
      Abstract: There is a need for accurate monitoring of PM2.5 that adversely affects human health. Consequently, in addition to the monitoring performed by fixed microbalance instruments installed under legal obligation, we are proposing to deploy the Pollutrack network of mobile sensors within the city of Paris (France). The measurements are performed by mobile aerosol counters mounted on the roof of cars, providing a constant series of readings in the 0.3–10 µm size range that are then aggregated to identify areas of mass concentrations of pollution. The performance of the Pollutrack sensors has been established in ambient air in comparison with the microbalance measurement devices and with the Light Optical Aerosols Counter (LOAC) aerosol counter. A measurement uncertainty of about 5 µg. m−3 is obtained with absolute values from the Pollutrack measurements made at a given location. Instead of the current modelizations based on very few PM2.5 values, maps built from real measurements with a spatial resolution down to 100 m can now be produced each day for Paris, and potentially for specific times of the day, thanks to the high number of measurements achievable with the Pollutrack system (over 70,000 on weekdays). Interestingly, the global trend of PM2.5 content shows several significant pollution events in 2020 despite the COVID-19 crisis and the lockdown. The Pollutrack pollution maps recorded during different PM2.5 pollution conditions in the city frequently identified a strong spatial heterogeneity where the North and the East of Paris were more polluted than the west. These “hot spots” could be due to the city topology and its sensitivity to wind direction and intensity. These high-resolution maps will be crucial in creating evidence for the relevant authorities to respond appropriately to local sources of pollution and to improve the understanding of transportation of urban PM.
      Citation: Atmosphere
      PubDate: 2021-04-21
      DOI: 10.3390/atmos12050529
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 530: Estimation and Prediction of Industrial
           VOC Emissions in Hebei Province, China

    • Authors: Xiurui Guo, Yaqian Shen, Wenwen Liu, Dongsheng Chen, Junfang Liu
      First page: 530
      Abstract: The study of industrial volatile organic compound (VOC) emission inventories is essential for identifying VOC emission levels and distribution. This paper established an industrial VOC emission inventory in 2015 for Hebei Province and completed an emission projection for the period 2020–2030. The results indicated that the total emissions of industrial VOCs in 2015 were 1017.79 kt. The use of VOC products accounted for more than half of the total. In addition, the spatial distribution characteristics of the industrial VOC emissions were determined using a geographic information statistics system (GIS), which showed that the VOCs were mainly distributed the central and southern regions of Hebei. Considering the future economic development trends, population changes, related environmental laws and regulations, and pollution control technology, three scenarios were defined for forecasting the industrial VOC emissions in future years. This demonstrated that industrial VOC emissions in Hebei would amount to 1448.94 kt and 2203.66 kt in 2020 and 2030, with growth rates of 42.36% and 116.51% compared with 2015, respectively. If all industrial enterprises took the control measures, the VOC emissions could be reduced by 69% in 2030. The analysis of the scenarios found that the most effective action plan was to take the best available control technologies and clean production in key industries, including the chemical medicine, coke production, mechanical equipment manufacturing, organic chemical, packaging and printing, wood adhesive, industrial and construction dye, furniture manufacturing, transportation equipment manufacturing, and crude oil processing industries.
      Citation: Atmosphere
      PubDate: 2021-04-21
      DOI: 10.3390/atmos12050530
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 531: Oxidative Potential of Atmospheric
           Aerosols

    • Authors: Maria Rachele Guascito, Maria Chiara Pietrogrande, Stefano Decesari, Daniele Contini
      First page: 531
      Abstract: Atmospheric particulate matter (PM) is one of the leading health risks worldwide [...]
      Citation: Atmosphere
      PubDate: 2021-04-21
      DOI: 10.3390/atmos12050531
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 532: A Time-Based Assessment of Particulate
           Matter (PM2.5) Levels at a Highly Trafficked Intersection: Case Study of
           Sango-Ota, Nigeria

    • Authors: David Olukanni, David Enetomhe, Gideon Bamigboye, Daniel Bassey
      First page: 532
      Abstract: Vehicle emissions have become one of the most prevailing air contamination sources, including nitrogen oxides, volatile organic compounds, carbon monoxide and particulate matter (PM). Among other air pollutants, PM limits visible sight distance and poses health risks upon inhalation into the human body. This study focused on assessing PM2.5 concentrations in air at different periods of the day at the highly trafficked grade-separated intersection of Sango-Ota, Ogun State, Nigeria. PM2.5 readings were taken at three at-grade points around the intersection’s roundabout between 10:00 a.m. and 5:00 p.m. for four (4) days using the BR-SMART-126 Portable 4-in-1 air quality monitor. The highest level of PM2.5 obtained on Day 1 (Monday) and Day 4 (Thursday) was about 45.1% and 38.6%, respectively, lower than that of Day 3 (Wednesday). The highest concentrations of PM2.5 were recorded between 11:00 and 13:00 and between 16:00 and 18:00 (up to 217 µg/m3) whereas the lowest levels were recorded between 14:00 and 15:00 (as low as 86 µg/m3). The concentration of PM2.5 at the Sango-Ota intersection is adjudged “very poor” with average hourly concentrations between 97 and 370 µg/m3. Outcomes obtained indicate the need for improved measures to control air quality along major road corridors and at intersections in Ogun State and Nigeria at large.
      Citation: Atmosphere
      PubDate: 2021-04-22
      DOI: 10.3390/atmos12050532
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 533: Emissions and Concentrations of
           Particulate Matter in Poznan Compared with Other Polish and European
           Cities

    • Authors: Remigiusz Jasiński, Marta Galant-Gołębiewska, Mateusz Nowak, Karolina Kurtyka, Paula Kurzawska, Marta Maciejewska, Monika Ginter
      First page: 533
      Abstract: It is estimated that the excessive emission of airborne particulate matter shortens the life expectancy of a European city inhabitant by up to eight months. The conducted comparison shows the emission and concentration of PM10 in Poznan against the supra-regional background. The purpose of the comparison with similar area and population cities is to identify the position of the Poznan agglomeration in terms of particulate matter emissions. The main sources are: original research, PM official measuring stations’ data, and the relevant organizations’ reports. On the basis of the conducted comparison, it can be concluded that Wroclaw and Poznan achieve very similar results in terms of emissions. Cracow, on the other hand, as a city where for several years there have been significant problems with the phenomenon of smog and excessive emission of particulate matter, reaches extremely different values compared to Poznan. The article presents also the air quality in Poznan and other Polish and European cities. There were also measurements of PM mass and number conducted in Poznan. The results show that there is a significant difference between the air quality measured at official measuring stations (only some of them are measuring PMs at all) and that measured with portable equipment in different parts of the city.
      Citation: Atmosphere
      PubDate: 2021-04-22
      DOI: 10.3390/atmos12050533
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 534: Characterization of Products from the
           Aqueous-Phase Photochemical Oxidation of Benzene-Diols

    • Authors: Yang Ou, Dongyang Nie, Hui Chen, Zhaolian Ye, Xinlei Ge
      First page: 534
      Abstract: Chemical processing in atmospheric aqueous phases, including cloud and fog drops, might be significant in reconciling the gap between observed and modeled secondary organic aerosol (SOA) properties. In this work, we conducted a relatively comprehensive investigation of the reaction products generated from the aqueous-phase photochemical oxidation of three benzene-diols (resorcinol, hydroquinone, and methoxyhydroquinone) by hydroxyl radical (·OH), triplet excited state (3C*) 3,4-dimethoxybenzaldehyde (3,4-DMB), and direct photolysis without any added oxidants. The results show that OH-initiated photo-degradation is the fastest of all the reaction systems. For the optical properties, the aqueous oxidation products generated under different reaction conditions all exhibited photo-enhancement upon illumination by simulated sunlight, and the light absorption was wavelength dependent on and increased as a function of the reaction time. The oxygen-to-carbon (O/C) ratio of the products also gradually increased against the irradiation time, indicating the persistent formation of highly oxygenated low-volatility products throughout the aging process. More importantly, aqueous-phase products from photochemical oxidation had an increased oxidative potential (OP) compared with its precursor, indicating they may more adversely impact health. The findings in this work highlight the importance of aqueous-phase photochemical oxidation, with implications for aqueous SOA formation and impacts on both the chemical properties and health effects of OA.
      Citation: Atmosphere
      PubDate: 2021-04-22
      DOI: 10.3390/atmos12050534
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 535: Lake and Land Breezes at a Mediterranean
           Artificial Lake: Observations in Alqueva Reservoir, Portugal

    • Authors: Carolina Purificação, Miguel Potes, Gonçalo Rodrigues, Rui Salgado, Maria João Costa
      First page: 535
      Abstract: The Alqueva reservoir, in the Southeast of Portugal, has significantly changed the landscape of the region, with impacts also on the local climate, as documented in this manuscript, namely the thermal circulation in the form of lake and land breezes. Taking advantage of three strategic meteorological stations, two installed at the shores and another on a floating platform located near the center of the reservoir, a detailed analysis of lake and land breeze occurrences during two years is presented in this study. The thermal gradient between the reservoir and the surroundings is the main driver for the breeze development and the meteorological stations placed in opposite sides of the reservoir allow to establish the criteria in order to detect lake and land breezes. The results showed more land breeze than lake breeze occurrences, in line with the more negative thermal gradient between shores and reservoir in the annual cycle. Lake breezes are more frequent in summer months during daytime and land breezes in turn are more frequent in winter months during night-time.
      Citation: Atmosphere
      PubDate: 2021-04-22
      DOI: 10.3390/atmos12050535
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 536: Shipping and Air Quality in Italian Port
           Cities: State-of-the-Art Analysis of Available Results of Estimated
           Impacts

    • Authors: Eva Merico, Daniela Cesari, Elena Gregoris, Andrea Gambaro, Marco Cordella, Daniele Contini
      First page: 536
      Abstract: Populated coastal areas are exposed to emissions from harbour-related activities (ship traffic, loading/unloading, and internal vehicular traffic), posing public health issues and environmental pressures on climate. Due to the strategic geographical position of Italy and the high number of ports along coastlines, an increasing concern about maritime emissions from Italian harbours has been made explicit in the EU and IMO (International Maritime Organization, London, UK) agenda, also supporting the inclusion in a potential Mediterranean emission control area (MedECA). This work reviews the main available outcomes concerning shipping (and harbours’) contributions to local air quality, particularly in terms of concentration of particulate matter (PM) and gaseous pollutants (mainly nitrogen and sulphur oxides), in the main Italian hubs. Maritime emissions from literature and disaggregated emission inventories are discussed. Furthermore, estimated impacts to air quality, obtained with dispersion and receptor modeling approaches, which are the most commonly applied methodologies, are discussed. Results show a certain variability that suggests the necessity of harmonization among methods and input data in order to compare results. The analysis gives a picture of the effects of this pollution source, which could be useful for implementing effective mitigation strategies at a national level.
      Citation: Atmosphere
      PubDate: 2021-04-22
      DOI: 10.3390/atmos12050536
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 537: Urban Resilience of Shenzhen City under
           Climate Change

    • Authors: Weiwei Shao, Xin Su, Jie Lu, Jiahong Liu, Zhiyong Yang, Chao Mei, Chuang Liu, Jiahui Lu
      First page: 537
      Abstract: The Chinese government attaches great importance to climate change adaptation and has issued relevant strategies and policies. Overall, China’s action to adapt to climate change remains in its infancy, and relevant research needs to be further deepened. In this paper, we study the future adaptive countermeasures of Shenzhen city in the Pearl River Delta in terms of climate change, especially urban flood risk resilience. Based on the background investigation of urban flood risk in Shenzhen, this paper calculates the annual precipitation frequency of Shenzhen from 1953 to 2020, and uses the extreme precipitation index as a quantitative indicator to analyze the changes in historical precipitation and the impact of major flood disasters in Shenzhen city in previous decades. Based on the six kinds of model data of the scenario Model Inter-comparison Project (MIP) in the sixth phase of the Coupled Model Inter-comparison Project (CMIP6), uses the Taylor diagram and MR comprehensive evaluation method to evaluate the ability of different climate models to simulate extreme precipitation in Shenzhen, and the selected models are aggregated and averaged to predict the climate change trend of Shenzhen from 2020 to 2100. The prediction results show that Shenzhen will face more severe threats from rainstorms and floods in the future. Therefore, this paper proposes a resilience strategy for the city to cope with the threat of flood in the future, including constructing a smart water management system and promoting the development of a sponge city. Moreover, to a certain extent, it is necessary to realize risk transfer by promoting a flood insurance system.
      Citation: Atmosphere
      PubDate: 2021-04-22
      DOI: 10.3390/atmos12050537
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 538: Non-Stationary Effects of the Arctic
           Oscillation and El Niño–Southern Oscillation on January Temperatures in
           Korea

    • Authors: Jae-Seung Yoon, Il-Ung Chung, Ho-Jeong Shin, Kunmnyeong Jang, Maeng-Ki Kim, Jeong-Soo Park, Doo-Sun R. Park, Kyung-On Boo, Young-Hwa Byun, Hyun Min Sung
      First page: 538
      Abstract: In recent decades, extremely cold winters have occurred repeatedly throughout the Northern Hemisphere, including the Korean Peninsula (hereafter, Korea). Typically, cold winter temperatures in Korea can be linked to the strengthening of the Siberian High (SH). Although previous studies have investigated the typical relationship between the SH and winter temperatures in Korea, this study uniquely focused on a change in the relationship, which reflects the influence of the Arctic Oscillation (AO) and El Niño–Southern Oscillation (ENSO). A significant change in the 15-year moving correlation between the SH and the surface air temperature average in Korea (K-tas) was observed in January. The correlation changed from −0.80 during 1971–1990 to −0.16 during 1991–2010. The mean sea-level pressure pattern regressed with the temperature, and a singular value decomposition analysis that incorporated the temperature and pressure supports that the negative high correlation during 1971–1990 was largely affected by AO. This connection with AO is substantiated by empirical orthogonal function (EOF) analysis with an upper-level geopotential height at 300 hPa. In the second mode of the EOF, the temperature and pressure patterns were primarily affected by ENSO during 1991–2010. Consequently, the interdecadal change in correlation between K-tas and the SH in January can be attributed to the dominant effect of AO from 1971–1990 and of ENSO from 1991–2010. Our results suggest that the relative importance of these factors in terms of the January climate in Korea has changed on a multidecadal scale.
      Citation: Atmosphere
      PubDate: 2021-04-22
      DOI: 10.3390/atmos12050538
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 539: Basic Statistical Estimation Outperforms
           Machine Learning in Monthly Prediction of Seasonal Climatic Parameters

    • Authors: Eslam A. Hussein, Mehrdad Ghaziasgar, Christopher Thron, Mattia Vaccari, Antoine Bagula
      First page: 539
      Abstract: Machine learning (ML) has been utilized to predict climatic parameters, and many successes have been reported in the literature. In this paper, we scrutinize the effectiveness of five widely used ML algorithms in the monthly prediction of seasonal climatic parameters using monthly image data. Specifically, we quantify the predictive performance of these algorithms applied to five climatic parameters using various combinations of features. We compare the predictive accuracy of the resulting trained ML models to that of basic statistical estimators that are computed directly from the training data. Our results show that ML never significantly outperforms the statistical baseline, and underperforms for most feature sets. Unlike previous similar studies, we provide error bars for the relative performance of different predictors based on jackknife estimates applied to differences in predictive error magnitudes. We also show that the practice of shuffling data sequences which was employed in some previous references leads to data leakage, resulting in over-estimated performance. Ultimately, the paper demonstrates the importance of using well-grounded statistical techniques when producing and analyzing the results of ML predictive models.
      Citation: Atmosphere
      PubDate: 2021-04-23
      DOI: 10.3390/atmos12050539
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 540: Tree-Ring Isotopes Provide Clues for Sink
           Limitation on Treeline Formation on the Tibetan Plateau

    • Authors: Xing Pu, Xiaochun Wang, Lixin Lyu
      First page: 540
      Abstract: Identifying what determines the high elevation limits of tree growth is crucial for predicting how treelines may shift in response to climate change. Treeline formation is either explained by a low-temperature restriction of meristematic activity (sink limitation) or by the photosynthetic constraints (source limitation) on the trees at the treeline. Our study of tree-ring stable isotopes in two Tibetan elevational transects showed that treeline trees had higher iWUE than trees at lower elevations. The combination of tree-ring δ13C and δ18O data further showed that photosynthesis was higher for trees at the treeline than at lower elevations. These results suggest that carbon acquisition may not be the main determinant of the upper limit of trees; other processes, such as immature tissue growth, may be the main cause of treeline formation. The tree-ring isotope analysis (δ13C and δ18O) suggests that Tibetan treelines have the potential to benefit from ongoing climate warming, due to their ability to cope with co-occurring drought stress through enhanced water use efficiency.
      Citation: Atmosphere
      PubDate: 2021-04-23
      DOI: 10.3390/atmos12050540
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 541: Effect of Grazing Intensities on Soil N2O
           Emissions from an Alpine Meadow of Zoige Plateau in China

    • Authors: Wei Zhan, Zhenan Yang, Jianliang Liu, Huai Chen, Gang Yang, Erxiong Zhu, Ji Hu, Lin Jiang, Liangfeng Liu, Dan Zhu, Yixin He, Chuan Zhao, Dan Xue, Changhui Peng
      First page: 541
      Abstract: The alpine meadow of Zoige Plateau plays a key role in local livestock production of cattle and sheep. However, it remains unclear how animal grazing or its intensity affect nitrous oxide (N2O) emissions, and the main driving factors. A grazing experiment including four grazing intensities (G0, G0.7, G1.2, G1.6 yak ha−1) was conducted between January 2013 and December 2014 to evaluate the soil nitrous oxide (N2O) fluxes under different grazing intensities in an alpine meadow on the eastern Qinghai–Tibet Plateau of China. The N2O fluxes were examined with gas collected by the static chamber method and by chromatographic concentration analysis. N2O emissions in the growing seasons (from May to September) were lower than that in non-growing seasons (from October to April) in 2013, 1.94 ± 0.30 to 3.37 ± 0.56 kg N2O ha−1 yr−1. Annual mean N2O emission rates were calculated as 1.17 ± 0.50 kg N2O ha−1 yr−1 in non-grazing land (G0) and 1.94 ± 0.23 kg N2O ha−1 yr−1 in the grazing land (G0.7, G1.2, and G1.6). The annual mean N2O flux showed no significant differences between grazing treatments in 2013. However, there were significantly greater fluxes from the G0.7 treatment than from the G1.6 treatment in 2014, especially in the growing season. Over the two years, the soil N2O emission rate was significantly negatively correlated with soil water-filled pore space (WFPS) and dissolved organic carbon (DOC) content as well as positively correlated with soil available phosphorus (P). No relationship was observed between soil N2O emission rate and temperature or rainfall. Our results showed that the meadow soils acted as a source of N2O for most periods and turned into a weak sink of N2O later during the sampling period. Our results highlight the importance of proper grazing intensity in reducing N2O emissions from alpine meadow. The interaction between grazing intensity and N2O emissions should be of more concern during future management of pastures in Zoige Plateau.
      Citation: Atmosphere
      PubDate: 2021-04-23
      DOI: 10.3390/atmos12050541
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 542: Methodological Aspects for the
           Implementation of the Air Pesticide Control and Surveillance Network
           (PESTNet) of the Valencian Region (Spain)

    • Authors: Antonio López, Pablo Ruiz, Vicent Yusà, Clara Coscollà
      First page: 542
      Abstract: A large amount of pesticide, applied mainly during agricultural practice, is released into the atmosphere, decreasing air quality and potentially causing public health problems. The Valencian region, after Andalusia, is the Spanish region with the highest consumption of pesticides owing to its large areas of agricultural land and the existence of crops that require intensive use of pesticides. In this work, we describe the sampling and analytical tools developed in the last decade and their transference to the Regional Department for Environment, where the main objective of the research was the creation and implementation of an Air pesticide control and surveillance network (PESTNet) in the Valencian region in Spain. To be able to confirm that the established strategies were appropriate, a pilot scheme comprising three different sampling stations (two rural and one urban) was developed and implemented in 2020. The results showed that as many as 30 pesticides were detected in the three sampling stations, with the frequency detection ranging from 6% (beta-endosulfan, chlorpropham, endosulfan-sulfate, kresoxim-m, prochloraz) to 100% (azoxystrobin, chlorpyrifos-m, metalaxyl-M). On the other hand, the concentrations of the pesticides found oscillated between 14.4 (boscalid) and 4373.0 pg m−3 (chlorpyrifos-m). Moreover, a risk assessment was carried out, and no risks were observed for the studied population (infants, children, and adults) in the evaluated stations.
      Citation: Atmosphere
      PubDate: 2021-04-23
      DOI: 10.3390/atmos12050542
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 543: Is New Always Better' Frontiers in
           Global Climate Datasets for Modeling Treeline Species in the Himalayas

    • Authors: Maria Bobrowski, Johannes Weidinger, Udo Schickhoff
      First page: 543
      Abstract: Comparing and evaluating global climate datasets and their effect on model performance in regions with limited data availability has received little attention in ecological modeling studies so far. In this study, we aim at comparing the interpolated climate dataset Worldclim 1.4, which is the most widely used in ecological modeling studies, and the quasi-mechanistical downscaled climate dataset Chelsa, as well as their latest versions Worldclim 2.1 and Chelsa 1.2, with regard to their suitability for modeling studies. To evaluate the effect of these global climate datasets at the meso-scale, the ecological niche of Betula utilis in Nepal is modeled under current and future climate conditions. We underline differences regarding methodology and bias correction between Chelsa and Worldclim versions and highlight potential drawbacks for ecological models in remote high mountain regions. Regarding model performance and prediction plausibility under current climatic conditions, Chelsa-based models significantly outperformed Worldclim-based models, however, the latest version of Chelsa contains partially inherent distorted precipitation amounts. This study emphasizes that unmindful usage of climate data may have severe consequences for modeling treeline species in high-altitude regions as well as for future projections, if based on flawed current model predictions. The results illustrate the inevitable need for interdisciplinary investigations and collaboration between climate scientists and ecologists to enhance climate-based ecological model quality at meso- to local-scales by accounting for local-scale physical features at high temporal and spatial resolution.
      Citation: Atmosphere
      PubDate: 2021-04-23
      DOI: 10.3390/atmos12050543
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 544: Impact of Tropical Cyclones on Inhabited
           Areas of the SWIO Basin at Present and Future Horizons. Part 1: Overview
           and Observing Component of the Research Project RENOVRISK-CYCLONE

    • Authors: Olivier Bousquet, Guilhem Barruol, Emmanuel Cordier, Christelle Barthe, Soline Bielli, Radiance Calmer, Elisa Rindraharisaona, Gregory Roberts, Pierre Tulet, Vincent Amelie, Frauke Fleischer-Dogley, Alberto Mavume, Jonas Zucule, Lova Zakariasy, Bruno Razafindradina, François Bonnardot, Manvendra Singh, Edouard Lees, Jonathan Durand, Dominique Mekies, Marine Claeys, Joris Pianezze, Callum Thompson, Chia-Lun Tsai, Romain Husson, Alexis Mouche, Stephane Ciccione, Julien Cattiaux, Fabrice Chauvin, Nicolas Marquestaut
      First page: 544
      Abstract: The international research program “ReNovRisk-CYCLONE” (RNR-CYC, 2017–2021) directly involves 20 partners from 5 countries of the south-west Indian-Ocean. It aims at improving the observation and modelling of tropical cyclones in the south-west Indian Ocean, as well as to foster regional cooperation and improve public policies adapted to present and future tropical cyclones risk in this cyclonic basin. This paper describes the structure and main objectives of this ambitious research project, with emphasis on its observing components, which allowed integrating numbers of innovative atmospheric and oceanic observations (sea-turtle borne and seismic data, unmanned airborne system, ocean gliders), as well as combining standard and original methods (radiosoundings and global navigation satellite system (GNSS) atmospheric soundings, seismic and in-situ swell sampling, drone and satellite imaging) to support research on tropical cyclones from the local to the basin-scale.
      Citation: Atmosphere
      PubDate: 2021-04-23
      DOI: 10.3390/atmos12050544
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 545: Climate Change Impacts and Strategies for
           Mitigation and Adaptation in Agriculture

    • Authors: Bruce A. McCarl, Chin-Hsien Yu, Witsanu Attavanich
      First page: 545
      Abstract: Agriculture is highly vulnerable to climate change-induced shifts in means, variability and extremes [...]
      Citation: Atmosphere
      PubDate: 2021-04-24
      DOI: 10.3390/atmos12050545
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 546: Comments about Urban Bioclimate Aspects
           for Consideration in Urban Climate and Planning Issues in the Era of
           Climate Change

    • Authors: Andreas Matzarakis
      First page: 546
      Abstract: In the era of climate change, before developing and establishing mitigation and adaptation measures that counteract urban heat island (UHI) effects [...]
      Citation: Atmosphere
      PubDate: 2021-04-24
      DOI: 10.3390/atmos12050546
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 547: Untangling Urban Sprawl and Climate
           Change: A Review of the Literature on Physical Planning and Transportation
           Drivers

    • Authors: Qiu Feng, Pierre Gauthier
      First page: 547
      Abstract: Significant efforts have been dedicated to studying the linkages between urban form, fossil energy consumption, and climate change. The theme of urban sprawl helped to federate a significant portion of such efforts. Yet, the research appears fragmented, at stems from different disciplines and mobilizes different methods to probe different aspects of the issue. This paper seeks to better understand the status of knowledge concerning the linkages between sprawl and climate change through a critical review of the literature published between 1979 and 2018. The exercise entailed revisiting how sprawl has been defined, characterized and measured, and how such parameters have informed the research themes and the approaches mobilized to study its impacts on climate change. For, sprawled environments contribute the climate change directly and indirectly, due to the individual or combined effects of its land use, land cover, urban form, and transportation characteristics. The results indicate that sprawl’s impacts have been mainly investigated in three principal streams of research and based on a limited number of factors or combinations of factors. Though a strong consensus emerges on the negative environmental costs of sprawl, including toward climate change, there remain ambiguities when trying to untangle and weigh specific causes.
      Citation: Atmosphere
      PubDate: 2021-04-24
      DOI: 10.3390/atmos12050547
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 548: Climate Transition from Warm-Dry to
           Warm-Wet in Eastern Northwest China

    • Authors: Jinhu Yang, Qiang Zhang, Guoyang Lu, Xiaoyun Liu, Youheng Wang, Dawei Wang, Weiping Liu, Ping Yue, Biao Zhu, Xinyu Duan
      First page: 548
      Abstract: During the second half of the 20th century, eastern Northwest China experienced a warming and drying climate change. To determine whether this trend has continued or changed during the present century, this study systematically analyzes the characteristics of warming and dry–wet changes in eastern Northwest China based on the latest observational data and World Climate Research Programme (WCRP) Coupled Model Intercomparison Project Phase 6 (CMIP6) collection data. The results show that eastern Northwest China has warmed continuously during the past 60 years with a sudden temperature change occurring in the late 1990s. However, the temperature in the 2000s decreased slowly, and that in the 2010s showed a warming trend. The amount of precipitation began to increase in the late 1990s, which indicates a contemporary climate transition from warm-dry to warm-wet in eastern Northwest China. The contribution of precipitation to humidity is significantly more than that of temperature. Long-term and interannual variations dominate the temperature change, with the contribution of the former much stronger than that of the latter. However, interannual variation dominates the precipitation change. The warming accelerates from period to period, and the temperature spatial consistently increased during the three most recent climatic periods. The precipitation decreased from 1961–1990 to 1981–2010, whereas its spatial consistency increased from 1981–2010 to 1991–2019. The significant warming and humidification which began in the late 1990s and is expected to continue until the end of the 21st century in the medium emission scenario. However, the current sub-humid climate will not easily be changed. The warming could cause a climate transition from warm temperate to subtropical by 2040. The dry-to-wet climate transition in eastern Northwest China could be related to a synergistic enhancement of the East Asian summer monsoon and the westerly circulation. This research provides a scientific decision-making basis for implementing western development strategies, ecological protection, and high-quality development of the Yellow River Basin Area as well as that for ecological construction planning and water resource management of eastern Northwest China.
      Citation: Atmosphere
      PubDate: 2021-04-24
      DOI: 10.3390/atmos12050548
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 549: Ambient Levels, Emission Sources and
           Health Effect of PM2.5-Bound Carbonaceous Particles and Polycyclic
           Aromatic Hydrocarbons in the City of Kuala Lumpur, Malaysia

    • Authors: Hamidah Suradi, Md Firoz Khan, Nor Asrina Sairi, Haasyimah Ab Rahim, Sumiani Yusoff, Yusuke Fujii, Kai Qin, Md. Aynul Bari, Murnira Othman, Mohd Talib Latif
      First page: 549
      Abstract: With increasing interest in understanding the contribution of secondary organic aerosol (SOA) to particulate air pollution in urban areas, an exploratory study was carried out to determine levels of carbonaceous aerosols and polycyclic aromatic hydrocarbons (PAHs) in the city of Kuala Lumpur, Malaysia. PM2.5 samples were collected using a high-volume sampler for 24 h in several areas in Kuala Lumpur during the north-easterly monsoon from January to March 2019. Samples were analyzed for water-soluble organic carbon (WSOC), organic carbon (OC), and elemental carbon (EC). Secondary organic carbon (SOC) in PM2.5 was estimated. Particle-bound PAHs were analyzed using gas chromatography-flame ionization detector (GC-FID). Average concentrations of WSOC, OC, and EC were 2.73 ± 2.17 (range of 0.63–9.12) µg/m3, 6.88 ± 4.94 (3.12–24.1) µg/m3, and 3.68 ± 1.58 (1.33–6.82) µg/m3, respectively, with estimated average SOC of 2.33 µg/m3, contributing 34% to total OC. The dominance of char-EC over soot-EC suggests that PM2.5 is influenced by biomass and coal combustion sources. The average of total PAHs was 1.74 ± 2.68 ng/m3. Source identification methods revealed natural gas and biomass burning, and urban traffic combustion as dominant sources of PAHs in Kuala Lumpur. A deterministic health risk assessment of PAHs was conducted for several age groups, including infant, toddler, children, adolescent, and adult. Carcinogenic and non-carcinogenic risk of PAH species were well below the acceptable levels recommended by the USEPA. Backward trajectory analysis revealed north-east air mass brought pollutants to the studied areas, suggesting the north-easterly monsoon as a major contributor to increased air pollution in Kuala Lumpur. Further work is needed using long-term monitoring data to understand the origin of PAHs contributing to SOA formation and to apply source-risk apportionment to better elucidate the potential risk factors posed by the various sources in urban areas in Kuala Lumpur.
      Citation: Atmosphere
      PubDate: 2021-04-24
      DOI: 10.3390/atmos12050549
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 550: Predictive Capacity of Rainfall Data to
           Estimate the Water Needs of Fruit Plants in Water Deficit Areas

    • Authors: Piotr Stachowski, Barbara Jagosz, Stanisław Rolbiecki, Roman Rolbiecki
      First page: 550
      Abstract: This study investigated the usefulness of three methods: (1) Press, (2) Grabarczyk and Rzekanowski, and (3) Treder, in estimating the water needs of apple, pear, cherry and plum trees grown in central Poland, where particular water deficits are observed. The assessments were based on meteorological data for the growing seasons 1989–2020. Orchard irrigation requires a simple and accessible method of estimating plant water requirements. The average water needs assessed for apple ranged from 435 mm (Press) to 729 mm (Grabarczyk and Rzekanowski), for pear between 353–699 mm (Grabarczyk and Rzekanowski), for cherry between 315 mm (Press) and 660 mm (Grabarczyk and Rzekanowski), and plum ranged from 455 mm (Press) to 718 mm (Grabarczyk and Rzekanowski). Regardless of the method used, precipitation in the studied period did not cover the water needs of the fruit trees. Additionally, there was a tendency to increase the water requirements of the plants. In each method, water needs in the second and third decades were higher than in the first. The highest water needs of the fruit trees were calculated using the Treder method, and the lowest using the Press method. In practice, each of the methods can be used to forecast the water needs of fruit plants, but the Treder method seems to be the simplest and most accessible.
      Citation: Atmosphere
      PubDate: 2021-04-24
      DOI: 10.3390/atmos12050550
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 551: Impact of Assimilating Ground-Based
           Microwave Radiometer Data on the Precipitation Bifurcation Forecast: A
           Case Study in Beijing

    • Authors: Yajie Qi, Shuiyong Fan, Jiajia Mao, Bai Li, Chunwei Guo, Shuting Zhang
      First page: 551
      Abstract: In this study, the temperature and relative humidity profiles retrieved from five ground-based microwave radiometers in Beijing were assimilated into the rapid-refresh multi-scale analysis and prediction system-short term (RMAPS-ST). The precipitation bifurcation prediction that occurred in Beijing on 4 May 2019 was selected as a case to evaluate the impact of their assimilation. For this purpose, two experiments were set. The Control experiment only assimilated conventional observations and radar data, while the microwave radiometers profilers (MWRPS) experiment assimilated conventional observations, the ground-based microwave radiometer profiles and radar data into the RMAPS-ST model. The results show that in comparison with the Control test, the MWRPS test made reasonable adjustments for the thermal conditions in time, better reproducing the weak heat island phenomenon in the observation prior to the rainfall. Thus, assimilating MWRPS improved the skills of the precipitation forecast in both the distribution and the intensity of rainfall precipitation, capable of predicting the process of belt-shaped radar echo splitting and the precipitation bifurcation in the urban area of Beijing. The assimilation of the ground-based microwave radiometer profiles improved the skills of the quantitative precipitation forecast to a certain extent. Among multiple cycle experiments, the onset of 0600 UTC cycle closest to the beginning of rainfall performed best by assimilating the ground-based microwave radiometer profiles.
      Citation: Atmosphere
      PubDate: 2021-04-25
      DOI: 10.3390/atmos12050551
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 552: Visibility Prediction over South Korea
           Based on Random Forest

    • Authors: Bu-Yo Kim, Joo Wan Cha, Ki-Ho Chang, Chulkyu Lee
      First page: 552
      Abstract: In this study, the visibility of South Korea was predicted (VISRF) using a random forest (RF) model based on ground observation data from the Automated Synoptic Observing System (ASOS) and air pollutant data from the European Centre for Medium-Range Weather Forecasts (ECMWF) Copernicus Atmosphere Monitoring Service (CAMS) model. Visibility was predicted and evaluated using a training set for the period 2017–2018 and a test set for 2019. VISRF results were compared and analyzed using visibility data from the ASOS (VISASOS) and the Unified Model (UM) Local Data Assimilation and Prediction System (LDAPS) (VISLDAPS) operated by the Korea Meteorological Administration (KMA). Bias, root mean square error (RMSE), and correlation coefficients (R) for the VISASOS and VISLDAPS datasets were 3.67 km, 6.12 km, and 0.36, respectively, compared to 0.14 km, 2.84 km, and 0.81, respectively, for the VISASOS and VISRF datasets. Based on these comparisons, the applied RF model offers significantly better predictive performance and more accurate visibility data (VISRF) than the currently available VISLDAPS outputs. This modeling approach can be implemented by authorities to accurately estimate visibility and thereby reduce accidents, risks to public health, and economic losses, as well as inform on urban development policies and environmental regulations.
      Citation: Atmosphere
      PubDate: 2021-04-25
      DOI: 10.3390/atmos12050552
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 553: The Historical Trend of Air Pollution and
           Its Impact on Human Health in Campania Region (Italy)

    • Authors: Domenico Toscano, Fabio Murena
      First page: 553
      Abstract: The Campania region covers an area of about 13,590 km2 with 5.8 million residents. The area suffers from several environmental issues due to urbanization, the presence of industries, wastewater treatment, and solid waste management concerns. Air pollution is one of the most relevant environmental troubles in the Campania region, frequently exceeding the limit values established by European directives. In this paper, airborne pollutant concentration data measured by the regional air quality network from 2003 to 2019 are collected to individuate the historical trends of nitrogen dioxide (NO2), coarse and fine particulate matter with aerodynamic diameters smaller than 10 μm (PM10) and 2.5 μm (PM2.5), and ozone (O3) through the analysis of the number of exceedances of limit values per year and the annual average concentration. Information on spatial variability and the effect of the receptor category is obtained by lumping together data belonging to the same province or category. To obtain information on the general air quality rather than on single pollutants, the European Air Quality Index (EU-AQI) is also evaluated. A special focus is dedicated to the effect of deep street canyons on air quality, since they are very common in the urban areas in Campania. Finally, the impact of air pollution from 2003 to 2019 on human health is also analyzed using the software AIRQ+.
      Citation: Atmosphere
      PubDate: 2021-04-25
      DOI: 10.3390/atmos12050553
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 554: Determination and Similarity Analysis of
           PM2.5 Emission Source Profiles Based on Organic Markers for Monterrey,
           Mexico

    • Authors: Yasmany Mancilla, Gerardo Medina, Lucy T. González, Pierre Herckes, Matthew P. Fraser, Alberto Mendoza
      First page: 554
      Abstract: Source attribution of airborne particulate matter (PM) relies on a host of different chemical species. Organic molecular markers are a set of particularly useful marker compounds for estimating source contributions to the fine PM fraction (i.e., PM2.5). Although there are many source apportionment studies based on organic markers, these studies heavily rely on the few studies that report region-specific emission profiles. Source attribution efforts, particularly those conducted in countries with emerging economies, benefit from ad hoc information to conduct the corresponding analyses. In this study, we report organic molecular marker source profiles for PM2.5 emitted from 12 major sources types from five general source categories (meat cooking operations, vehicle exhausts, industries, biomass and trash burning, and urban background) for the Monterrey Metropolitan Area (Mexico). Source emission samples were obtained from a ground-based source-dominated sampling approach. Filter-based instruments were utilized, and the loaded filters were chemically characterized for organic markers by GC-MS. Levoglucosan and cholesterol dominate charbroiled-cooking operation sources while methoxyphenols, PAHs and hopanes dominate open-waste burning, vehicle exhaust and industrial emissions, respectively. A statistical analysis showed values of the Pearson distance < 0.4 and the similarity identity distance > 0.8 in all cases, indicating dissimilar source profiles. This was supported by the coefficient of divergence average values that ranged from 0.62 to 0.72. These profiles could further be utilized in receptor models to conduct source apportionment in regions with similar characteristics and can also be used to develop air pollution abatement strategies.
      Citation: Atmosphere
      PubDate: 2021-04-26
      DOI: 10.3390/atmos12050554
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 555: Impact of Encouraging Vehicles to Refuel
           at Night on Ozone and Non-Methane Hydrocarbons (NMHCs): A Case Study in
           Ji’nan, China

    • Authors: Wenxuan Chai, Yaolong Shi, Kun Hu, Yujing Hou, Siyuan Liang, Wentai Chen, Ming Wang, Guigang Tang
      First page: 555
      Abstract: Gasoline evaporation is a potential source of ambient non-methane hydrocarbons (NMHCs) during summer, and thus the policy of encouraging vehicles to refuel at night has been implemented to control ground-level ozone (O3) and NMHCs. In this study, NMHCs and trace gases were observed online at an urban site of Ji’nan during May–July in 2019 and 2020 to assess the impact of this policy. After the implementation of this policy, the average concentration of daily maximum 8 h moving average O3 decreased from 198 μg/m3 to 181 μg/m3. Meanwhile, the average mixing ratio of NMHCs decreased from 19.89 ppbv to 18.02 ppbv. Sources of NMHCs were then apportioned using the positive matrix factorization model. Four factors were resolved and identified, including vehicle exhaust, paint and solvents usage, gasoline evaporation, and biogenic emission. Relative contributions of these four sources were 52.5%, 20.6%, 18.3%, and 8.6%, respectively. After the implementation of this policy, relative contributions of gasoline evaporation in 1:00–4:00 increased from 20.2–22.7% to 25.4–28.2%, while those for 16:00–18:00 decreased from 16.8–18.7% to 13.9–15.7%. The non-linear relationship of O3 with NMHCs and NOx was investigated using a box model based on observations. Results suggest that O3 production was mainly controlled by NMHCs. Aromatics and alkenes were the key NMHC species in O3 formation. Furthermore, two scenarios of encouraging vehicles to refuel at night were designed to evaluate their impact on O3. The relative decreases of O3 peak concentrations were lower than 1%, indicating that this policy had a limited impact on O3 during the observation period.
      Citation: Atmosphere
      PubDate: 2021-04-26
      DOI: 10.3390/atmos12050555
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 556: A Study on the Mechanisms Accounting for
           the Generation of a Southwest Vortex That Caused a Series of Severe
           Disasters during the 2020 Abnormal Meiyu Season

    • Authors: Hui Ma, Xiaolei Ma, Yanwei Jing, Guiping Wu
      First page: 556
      Abstract: The abnormal 2020 Meiyu season caused the worst disasters over the Yangtze River Valley in recent decades. Of these, the Sichuan Basin (SCB) and its surrounding regions were one of the most severely affected areas. Disastrous weather frequently occurs in these regions, with a large proportion of it closely related to the southwest vortices (SWVs). In order to further the understanding of SWV generation, this study investigated the formation mechanisms of a quasi-stationary SWV (by using two sets of vorticity budgets), which caused torrential rainfall (resulting in flash floods in Sichuan and Chongqing), lightning activities (causing tripping incidents of transmission lines in Sichuan) and strong winds (leading to shutting down of wind turbines in Hubei). Results showed that the SWV was generated in a favorable background environment, during which an upper-tropospheric divergence and a middle-tropospheric warm advection appeared over the SCB. Trajectory analyses and vorticity budget showed that the air particles that came from the lower troposphere of the regions south of the Tibetan Plateau dominated the SWV formation. These air particles experienced notable ascending during which an increase in their cyclonic vorticity occurred mainly due to convergence-related stretching, whereas, tilting mainly decelerated this increase. The air particles sourced from the areas within the key region of the SWV and areas northeast of the key region were the second dominant factor for the vortex formation. Overall, for the air particles that formed the SWV, their most rapid changes of vorticity and divergence appeared in the period 24 h before SWV formation, implying that this was the critical period for the SWV generation.
      Citation: Atmosphere
      PubDate: 2021-04-26
      DOI: 10.3390/atmos12050556
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 557: Double High-Level Ozone and PM2.5
           Co-Pollution Episodes in Shanghai, China: Pollution Characteristics and
           Significant Role of Daytime HONO

    • Authors: Kejing Yang, Lingdong Kong, Songying Tong, Jiandong Shen, Lu Chen, Shengyan Jin, Chao Wang, Fei Sha, Lin Wang
      First page: 557
      Abstract: In recent years, high fine particulate (PM2.5) pollution episodes with high ozone (O3) levels have been observed in Shanghai from time to time. However, their occurrence and characteristics remain poorly understood. Meanwhile, as a major precursor of tropospheric hydroxyl radical (OH) that initiates the formation of hydroperoxyl and organic peroxy radicals, HONO would inevitably affect the formation of O3, but its role in the formation of O3 during the double high-level PM2.5 and O3 pollution episodes remains unclear. In this study, the characteristics of the double high pollution episodes and the role of HONO in O3 formation in these episodes were investigated based on field observation in urban Shanghai from 2014 to 2016. Results showed that high PM2.5 pollution and high O3 pollution could occur simultaneously. The cases with data of double high O3 and PM2.5 concentrations accounted for about 1.0% of the whole sampling period. During the double high pollution episodes, there still existed active photochemical processes, while the active photochemical processes at high PM2.5 concentration were conductive to the production and accumulation of O3 under a VOC-limited regime and a calm atmospheric condition including high temperature, moderately high relative humidity, and low wind speed, which in turn enhanced the conversions of SO2 and NO2 and the formation and accumulation of secondary sulfate and nitrate aerosols and further promoted the increase of PM2.5 concentration and the deterioration of air pollution. Further analysis indicated that the daytime HONO concentration could be strongly negatively correlated with O3 concentration in most of the double high pollution episodes, revealing the dominant role of HONO in O3 formation during these pollution episodes. This study provides important field measurement-based evidence for understanding the significant contribution of daytime HONO to O3 formation, and helps to clarify the formation and coexistence mechanisms of the double high-level O3 and PM2.5 pollution episodes.
      Citation: Atmosphere
      PubDate: 2021-04-26
      DOI: 10.3390/atmos12050557
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 558: Development and Application of a Wide
           Dynamic Range and High Resolution Atmospheric Aerosol Water-Based
           Supersaturation Condensation Growth Measurement System

    • Authors: Jiejie Bian, Huaqiao Gui, Xiuli Wei, Tongzhu Yu, Zhibo Xie, Jie Wang, Jianguo Liu
      First page: 558
      Abstract: The supersaturated condensation of atmospheric aerosol is important in the study of mechanisms of cloud condensation and even heavy air pollution. The existing technology cannot realize accurate dynamic control of wide range supersaturation, so it is difficult to study condensation growth characteristics of nanoparticles through different levels of supersaturation. Here, a supersaturated condensation growth measurement system with three-stage microscope pipes was developed. The resolution of supersaturated condensation system is 0.14, within the range of 0.92 to 2.33 after calibration. Stabilization time is only about 80 s for saturation range 0.92–1.01, which helps to control saturation rapidly, and the control deviation of saturation is no more than 0.06. Measurement of different supersaturated condensation growth control conditions showed that, the particle size increased significantly compared with hygroscopic growth at high humidity. For single-component particles, the increase in size increased to a similar size at the same saturation, with a difference within 7.4%. The increase in size for ammonium sulfate (AS) increased by 13.4–30.2% relative to that of glucose. For the mixed-component, the increase in size decreased about 15.9–25.0% with the increase of the glucose. Because the glucose coating on the surface of AS have hindered particle growth. This also shows that atmospheric ultrafine particles, especially inorganic salt particles, will rapidly grow into larger particles under supersaturated conditions such as increased environmental humidity, thus having some impact on environmental pollution and climate change.
      Citation: Atmosphere
      PubDate: 2021-04-26
      DOI: 10.3390/atmos12050558
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 559: Current Trend of Carbon Emissions from
           Wildfires in Siberia

    • Authors: Evgenii Ponomarev, Nikita Yakimov, Tatiana Ponomareva, Oleg Yakubailik, Susan G. Conard
      First page: 559
      Abstract: Smoke from wildfires in Siberia often affects air quality over vast territories of the Northern hemisphere during the summer. Increasing fire emissions also affect regional and global carbon balance. To estimate annual carbon emissions from wildfires in Siberia from 2002–2020, we categorized levels of fire intensity for individual active fire pixels based on fire radiative power data from the standard MODIS product (MOD14/MYD14). For the last two decades, estimated annual direct carbon emissions from wildfires varied greatly, ranging from 20–220 Tg C per year. Sporadic maxima were observed in 2003 (>150 Tg C/year), in 2012 (>220 Tg C/year), in 2019 (~180 Tg C/year). However, the 2020 fire season was extraordinary in terms of fire emissions (~350 Tg C/year). The estimated average annual level of fire emissions was 80 ± 20 Tg C/year when extreme years were excluded from the analysis. For the next decade the average level of fire emissions might increase to 250 ± 30 Tg C/year for extreme fire seasons, and to 110 ± 20 Tg C/year for moderate fire seasons. However, under the extreme IPCC RPC 8.5 scenario for Siberia, wildfire emissions might increase to 1200–1500 Tg C/year by 2050 if there were no significant changes in patterns of vegetation distribution and fuel loadings.
      Citation: Atmosphere
      PubDate: 2021-04-26
      DOI: 10.3390/atmos12050559
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 560: Temperature of Paved Streets in Urban
           Mockups and Its Implication of Reflective Cool Pavements

    • Authors: Yi Zhang, Peiyuan Wei, Lei Wang, Yinghong Qin
      First page: 560
      Abstract: In summer, urban heat islands increase building cooling demands, aggravate air pollution, and cause heat-related illnesses. As a mitigation strategy, reflective cool pavements have been deemed an effective measure to decrease the temperature in urban areas. However, the reflection of paved streets in an urban area will be different from that in an open area. It remains unknown which fraction of paved streets needs to be cooled upmost, and if increasing the albedo of paved streets can effectively reduce their temperature. This study measured the skin temperature of two urban mockups, of which one contained white streets and the other, gray streets. The streets were orientated at different strikes. It was found that in summer the East-West street was hotter than both the cross street and the South-North street. At nighttime, the heat released from building blocks kept the paved street about 0.2 °C hotter than paved areas in open spaces. It was also found that street orientation controlled the skin temperature of an urban street while the sky view factor (or building height and street width) acted in a secondary role only. Increasing the albedo of the paved street in an urban canyon effectively reduced the skin temperature of the street. Reflective pavements should be built preferentially on East-West streets and the cross streets.
      Citation: Atmosphere
      PubDate: 2021-04-26
      DOI: 10.3390/atmos12050560
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 561: Effects of COVID-Induced Mobility
           Restrictions and Weather Conditions on Air Quality in Hungary

    • Authors: Adrienn Varga-Balogh, Ádám Leelőssy, Róbert Mészáros
      First page: 561
      Abstract: Similarly to other countries, the first wave of the COVID pandemic induced a collapse of mobility in Hungary during the spring of 2020. From the environmental perspective, the obtained road traffic reduction of 20–50% could be regarded as an undesired traffic regulation experiment. Air quality impacts within Hungary were evaluated based on data from 52 monitoring sites measuring concentrations of pollutants NOx, O3, and PM10. Air pollution during the lockdown was compared to the same period (February–June) in the reference years 2014–2019. The large spatial heterogeneity of the air quality response was explored. The emission reduction coincided with the extreme weather of 2020, characterized by unusually warm pre-lockdown February and spring drought. The anomalously low pre-lockdown air pollution was further reduced (NOx) or increased (PM10) during the restrictions. Compared to the previous years, NOx concentrations during the curfew were found to differ between −4.1 and +0.2 standard deviations (median −1.55 SD), or −45% and +3% (median −18%) among different monitoring locations. Ozone concentrations were unusually high due to both weather and chemical reasons (median +11% or +0.8 SD), while the PM10 response was modest and largely weather-driven (median +7% or +0.4 SD).
      Citation: Atmosphere
      PubDate: 2021-04-27
      DOI: 10.3390/atmos12050561
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 562: Evolution of Gaseous and Particulate
           Pollutants in the Air: What Changed after Five Lockdown Weeks at a
           Southwest Atlantic European Region (Northwest of Spain) Due to the
           SARS-CoV-2 Pandemic'

    • Authors: Jorge Moreda-Piñeiro, Joel Sánchez-Piñero, María Fernández-Amado, Paula Costa-Tomé, Nuria Gallego-Fernández, María Piñeiro-Iglesias, Purificación López-Mahía, Soledad Muniategui-Lorenzo
      First page: 562
      Abstract: Due to the exponential growth of the SARS-CoV-2 pandemic in Spain (2020), the Spanish Government adopted lockdown measures as mitigating strategies to reduce the spread of the pandemic from 14 March. In this paper, we report the results of the change in air quality at two Atlantic Coastal European cities (Northwest Spain) during five lockdown weeks. The temporal evolution of gaseous (nitrogen oxides, comprising NOx, NO, and NO2; sulfur dioxide, SO2; carbon monoxide, CO; and ozone, O3) and particulate matter (PM10; PM2.5; and equivalent black carbon, eBC) pollutants were recorded before (7 February to 13 March 2020) and during the first five lockdown weeks (14 March to 20 April 2020) at seven air quality monitoring stations (urban background, traffic, and industrial) in the cities of A Coruña and Vigo. The influences of the backward trajectories and meteorological parameters on air pollutant concentrations were considered during the studied period. The temporal trends indicate that the concentrations of almost all species steadily decreased during the lockdown period with statistical significance, with respect to the pre-lockdown period. In this context, great reductions were observed for pollutants related mainly to fossil fuel combustion, road traffic, and shipping emissions (−38 to −78% for NO, −22 to −69% for NO2, −26 to −75% for NOx, −3 to −77% for SO2, −21% for CO, −25 to −49% for PM10, −10 to −38% for PM2.5, and −29 to −51% for eBC). Conversely, O3 concentrations increased from +5 to +16%. Finally, pollutant concentration data for 14 March to 20 April of 2020 were compared with those of the previous two years. The results show that the overall air pollutants levels were higher during 2018–2019 than during the lockdown period.
      Citation: Atmosphere
      PubDate: 2021-04-27
      DOI: 10.3390/atmos12050562
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 563: Evaluation of a Novel Poultry Litter
           Amendment on Greenhouse Gas Emissions

    • Authors: Kelsey Anderson, Philip A. Moore, Jerry Martin, Amanda J. Ashworth
      First page: 563
      Abstract: Gaseous emissions from poultry litter causes production problems for producers as well as the environment, by contributing to climate change and reducing air quality. Novel methods of reducing ammonia (NH3) and greenhouse gas (GHG) emissions in poultry facilities are needed. As such, our research evaluated GHG emissions over a 42 d period. Three separate flocks of 1000 broilers were used for this study. The first flock was used only to produce litter needed for the experiment. The second and third flocks were allocated to 20 pens in a randomized block design with four replicated of five treatments. The management practices studied included an unamended control; a conventional practice of incorporating aluminum sulfate (referred to as alum) at 98 kg/100 m2); a novel litter amendment made from alum mud, bauxite, and sulfuric acid (alum mud litter amendment, AMLA) applied at different rates (49 and 98 kg/100 m2) and methods (surface applied or incorporated). Nitrous oxide emissions were low for all treatments in flocks 2 and 3 (0.40 and 0.37 mg m2 hr−1, respectively). The formation of caked litter (due to excessive moisture) during day 35 and 42 caused high variability in CH4 and CO2 emissions. Alum mud litter amendment and alum did not significantly affect GHGs emissions from litter, regardless of the amendment rate or application method. In fact, litter amendments such as alum and AMLA typically lower GHG emissions from poultry facilities by reducing ventilation requirements to maintain air quality in cooler months due to lower NH3 levels, resulting in less propane use and concomitant reductions in CO2 emissions.
      Citation: Atmosphere
      PubDate: 2021-04-28
      DOI: 10.3390/atmos12050563
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 564: Method for Measuring the Second-Order
           Moment of Atmospheric Turbulence

    • Authors: Hong Shen, Longkun Yu, Xu Jing, Fengfu Tan
      First page: 564
      Abstract: The turbulence moment of order m (μm) is defined as the refractive index structure constant Cn2 integrated over the whole path z with path-weighting function zm. Optical effects of atmospheric turbulence are directly related to turbulence moments. To evaluate the optical effects of atmospheric turbulence, it is necessary to measure the turbulence moment. It is well known that zero-order moments of turbulence (μ0) and five-thirds-order moments of turbulence (μ5/3), which correspond to the seeing and the isoplanatic angles, respectively, have been monitored as routine parameters in astronomical site testing. However, the direct measurement of second-order moments of turbulence (μ2) of the whole layer atmosphere has not been reported. Using a star as the light source, it has been found that μ2 can be measured through the covariance of the irradiance in two receiver apertures with suitable aperture size and aperture separation. Numerical results show that the theoretical error of this novel method is negligible in all the typical turbulence models. This method enabled us to monitor μ2 as a routine parameter in astronomical site testing, which is helpful to understand the characteristics of atmospheric turbulence better combined with μ0 and μ5/3.
      Citation: Atmosphere
      PubDate: 2021-04-28
      DOI: 10.3390/atmos12050564
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 565: Physicochemical Analysis of Water Extracts
           of Particulate Matter from Polluted Air in the Area of Kraków, Poland

    • Authors: Magdalena Mikrut, Wojciech Macyk, Rudi van Eldik, Grażyna Stochel
      First page: 565
      Abstract: Solubility of transition metal compounds plays a significant role in adverse health effects because that is one of the most important factors of particulate matter bioavailability in the body. In this study, we focus on the chemical analysis of particulate matter (PM) collected at different locations in the area of Kraków, one of the most polluted cities in Poland, and compare them with Standard Reference Material (SRM) 1648a from NIST. The content of four elements (carbon, hydrogen, nitrogen, and sulfur) was determined by elemental analysis, and the ratio between organic and inorganic carbon in PM extracts was confirmed by Total Organic Carbon analysis. Among the most concentrated elements found there are calcium, magnesium, sulfur, silicon, and zinc, whereas copper, iron, and manganese were present in lower concentrations. SEM-EDS analysis showed a similar morphology of the SRM and PM collected in the urban area of Kraków, while PM collected in the industrial area has smaller particles with a smooth surface. The reported analyses are significant for the APARIC project (“Air Pollution versus Autoimmunity: Role of multiphase aqueous Inorganic Chemistry”), which aims to identify the main inorganic components of PM and to understand how they affect the development of immunological diseases.
      Citation: Atmosphere
      PubDate: 2021-04-28
      DOI: 10.3390/atmos12050565
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 566: Field Study on Nationality Differences in
           Adaptive Thermal Comfort of University Students in Dormitories during
           Summer in Japan

    • Authors: Vanya Y. Draganova, Hiroki Yokose, Kazuyo Tsuzuki, Yuki Nabeshima
      First page: 566
      Abstract: A summer field study was conducted in two university dormitories in the Tokai region of Central Japan. The study aimed at understanding the correlation between subjective thermal responses as well as whether nationality was affecting the responses. It was observed that nationality significantly affected thermal sensitivity and preference. The occupants’ acceptance for thermal stress was invariably above 90%. Despite the high levels of humidity observed, the multiple regression model showed that only the indoor air temperature was significant for explaining the variability of thermal sensation for both Japanese and non-Japanese students. The highest probability of voting neutral for university students in dormitory buildings in the Tokai region of Japan was estimated within 24~26.5 °C (by probit analysis). Japanese students were more sensitive to their indoor environment as opposed to the international students. The adjusted linear regression coefficient yielded from the room-wise day-wise averages were 0.48/K and 0.35/K for Japanese sensitivity and international sensitivity, respectively. In our study, the Griffiths’ model of estimating comfort temperature (or thermal neutrality) showed weak predictability and notable differences from the actually voted comfort. The neutral and comfort temperature observed and estimated in the study remained invariably below the recommended temperature threshold for Japan in summer leading to believe that that threshold is worth reevaluating.
      Citation: Atmosphere
      PubDate: 2021-04-28
      DOI: 10.3390/atmos12050566
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 567: Geographic Shift and Environment Change of
           U.S. Tornado Activities in a Warming Climate

    • Authors: Zuohao Cao, Huaqing Cai, Guang J. Zhang
      First page: 567
      Abstract: Even with ever-increasing societal interest in tornado activities engendering catastrophes of loss of life and property damage, the long-term change in the geographic location and environment of tornado activity centers over the last six decades (1954–2018), and its relationship with climate warming in the U.S., is still unknown or not robustly proved scientifically. Utilizing discriminant analysis, we show a statistically significant geographic shift of U.S. tornado activity center (i.e., Tornado Alley) under warming conditions, and we identify five major areas of tornado activity in the new Tornado Alley that were not identified previously. By contrasting warm versus cold years, we demonstrate that the shift of relative warm centers is coupled with the shifts in low pressure and tornado activity centers. The warm and moist air carried by low-level flow from the Gulf of Mexico combined with upward motion acts to fuel convection over the tornado activity centers. Employing composite analyses using high resolution reanalysis data, we further demonstrate that high tornado activities in the U.S. are associated with stronger cyclonic circulation and baroclinicity than low tornado activities, and the high tornado activities are coupled with stronger low-level wind shear, stronger upward motion, and higher convective available potential energy (CAPE) than low tornado activities. The composite differences between high-event and low-event years of tornado activity are identified for the first time in terms of wind shear, upward motion, CAPE, cyclonic circulation and baroclinicity, although some of these environmental variables favorable for tornado development have been discussed in previous studies.
      Citation: Atmosphere
      PubDate: 2021-04-28
      DOI: 10.3390/atmos12050567
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 568: Surface and Tropospheric Response of North
           Atlantic Summer Climate from Paleoclimate Simulations of the Past
           Millennium

    • Authors: Maria Pyrina, Eduardo Moreno-Chamarro, Sebastian Wagner, Eduardo Zorita
      First page: 568
      Abstract: We investigate the effects of solar forcing on the North Atlantic (NA) summer climate, in climate simulations with Earth System Models (ESMs), over the preindustrial past millennium (AD 850–1849). We use one simulation and a four-member ensemble performed with the MPI-ESM-P and CESM-LME models, respectively, forced only by low-scaling variations in Total Solar Irradiance (TSI). We apply linear methods (correlation and regression) and composite analysis to estimate the NA surface and tropospheric climatic responses to decadal solar variability. Linear methods in the CESM ensemble indicate a weak summer response in sea-level pressure (SLP) and 500-hPa geopotential height to TSI, with decreased values over Greenland and increased values over the NA subtropics. Composite analysis indicates that, during high-TSI periods, SLP decreases over eastern Canada and the geopotential height at 500-hPa increases over the subtropical NA. The possible summer response of SSTs is overlapped by model internal variability. Therefore, for low-scaling TSI changes, state-of-the-art ESMs disagree on the NA surface climatic effect of solar forcing indicated by proxy-based studies during the preindustrial millennium. The analysis of control simulations indicates that, in all climatic variables studied, spurious patterns of apparent solar response may arise from the analysis of single model simulations.
      Citation: Atmosphere
      PubDate: 2021-04-28
      DOI: 10.3390/atmos12050568
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 569: Characteristics of PM2.5 Pollution with
           Comparative Analysis of O3 in Autumn–Winter Seasons of Xingtai, China

    • Authors: Han Wang, Shulan Wang, Jingqiao Zhang, Hui Li
      First page: 569
      Abstract: Pollutants emission, meteorological conditions, secondary formation, and pollutants transport are the main reasons for air pollution. A comprehensive air pollution analysis was conducted from the above four aspects in the autumn–winter seasons of 2017–2018 and 2018–2019 at Xingtai, China. In addition, the relationship between PM2.5 and O3 was also studied from the aspects of secondary formation and meteorological conditions to find the rules of cooperative management of PM2.5 and O3 combined pollution. Taking measures of concentrated and clean heating and controlling biomass burning could make the concentrations of EC, K+ and SO42− decrease. The variation trends of PM2.5 and O3 concentration in the autumn–winter season of Xingtai were different, and with the increase in secondary formation effects, the concentration of O3 decreased. Furthermore, the key meteorological conditions that affected O3 and PM2.5 formation were temperature and relative humidity, respectively. The relationships of NOR (nitrate oxidation rate) and SOR (sulfate oxidation rate) against temperature presented a “U” shape, suggesting that gas-phase oxidation and gas–solid-phase oxidation were all suppressed at a temperature of around 4 °C. The cities located in the east had more pollutant transporting effects during the pollution processes of Xingtai, and the main transport routes of O3 and PM2.5 were not all the same.
      Citation: Atmosphere
      PubDate: 2021-04-28
      DOI: 10.3390/atmos12050569
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 570: A Feature Extraction and Classification
           Method to Forecast the PM2.5 Variation Trend Using Candlestick and Visual
           Geometry Group Model

    • Authors: Rui Xu, Xiaoming Liu, Hang Wan, Xipeng Pan, Jian Li
      First page: 570
      Abstract: Currently, the continuous change prediction of PM2.5 concentration is an air pollution research hotspot. Combining physical methods and deep learning models to divide the pollution process of PM2.5 into effective multiple types is necessary to achieve a reliable prediction of the PM2.5 value. Therefore, a candlestick chart sample generator was designed to generate the candlestick chart from the online PM2.5 continuous monitoring data of the Guilin monitoring station site. After these generated candlestick charts were analyzed through the Gaussian diffusion model, it was found that the characteristics of the physical transmission process of PM2.5 pollutants can be reflected. Based on a set three-day period, using the time linear convolution method, 2188 sets of candlestick chart data were obtained from the 2013–2018 PM2.5 concentration data. There existed 16 categories generated by unsupervised classification that met the established classification judgment standards. After the statistical analysis, it was found that the accuracy rate of the change trend of these classifications reached 99.68% during the next period. Using the candlestick chart data as the training dataset, the Visual Geometry Group (VGG) model, an improved convolutional neural network model, was used for the classification. The experimental results showed that the overall accuracy (OA) value of the candlestick chart combination classification was 96.19%, and the Kappa coefficient was 0.960. IN the VGG model, the overall accuracy was improved by 1.93%, on average, compared with the support vector machines (SVM), LeNet, and AlexNet models. According to the experimental results, using the VGG classification method to classify continuous pollution data in the form of candlestick charts can more comprehensively retain the characteristics of the physical pollution process and provide a classification basis for accurately predicting PM2.5 values. At the same time, the statistical feasibility of this method has been proved.
      Citation: Atmosphere
      PubDate: 2021-04-28
      DOI: 10.3390/atmos12050570
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 571: Gross Alpha and Gross Beta Activity
           Concentrations in the Dust Fractions of Urban Surface-Deposited Sediment
           in Russian Cities

    • Authors: Mohamed Y. Hanfi, Ilia Yarmoshenko, Andrian A. Seleznev
      First page: 571
      Abstract: Studies of gross alpha and gross beta activity in road- and surface-deposited sediments were conducted in three Russian cities in different geographical zones. To perform radiation measurements, new methods were applied which allow dealing with low mass and low volume dust-sized (2–100 μm) samples obtained after the size fractionation procedure. The 2–10 μm fraction size had the highest gross beta activity concentration (GB)—1.32 Bq/g in Nizhny Novgorod and Rostov-On-Don, while the 50–100 μm fraction size was most prominent in Ekaterinburg. This can be attributed to the presence of radionuclides that are transferred through natural and anthropogenic processes. The highest gross alpha activity concentration (GA) in fraction sizes was found in Rostov-on-Don city within the 50–100 μm range—0.22 Bq/g. The fraction sizes 50–100 μm have a higher gross alpha activity concentration than 2–10 μm and 10–50 μm fraction sizes due to natural partitioning of the main minerals constituting the urban surface-deposited sediment (USDS). Observed dependencies reflect the geochemical processes which take place during the formation and transport of urban surface sediments. Developed experimental methods of radiation measurements formed the methodological base of urban geochemical studies.
      Citation: Atmosphere
      PubDate: 2021-04-28
      DOI: 10.3390/atmos12050571
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 572: Effect of Urban Heat Island and Global
           Warming Countermeasures on Heat Release and Carbon Dioxide Emissions from
           a Detached House

    • Authors: Daisuke Narumi, Ronnen Levinson, Yoshiyuki Shimoda
      First page: 572
      Abstract: Urban air temperature rises induced by the urban heat island (UHIE) effect or by global warming (GW) can be beneficial in winter but detrimental in summer. The SCIENCE-Outdoor model was used to simulate changes to sensible heat release and CO2 emissions from buildings yielded by four UHIE countermeasures and five GW countermeasures. This model can evaluate the thermal condition of building envelope surfaces, both inside and outside. The results showed that water-consuming UHIE countermeasures such as evaporative space cooling and roof water showering provided positive effects (decreasing sensible heat release and CO2 emissions related to space conditioning) in summer. Additionally, they had no negative (unwanted cooling) effects in winter since they can be turned off in the heating season. Roof greening can provide the greatest space- conditioning CO2 emissions reductions among four UHIE countermeasures, and it reduces the amount of heat release slightly in the heating season. Since the effect on reducing carbon dioxide (CO2) emissions by UHIE countermeasures is not very significant, it is desirable to introduce GW countermeasures in order to reduce CO2 emissions. The significance of this study is that it constructed the new simulation model SCIENCE-Outdoor and applied it to show the influence of countermeasures upon both heat release and CO2 emissions.
      Citation: Atmosphere
      PubDate: 2021-04-28
      DOI: 10.3390/atmos12050572
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 573: Fluctuation of Lower Ionosphere Associated
           with Energetic Electron Precipitations during a Substorm

    • Authors: Tongxing Fu, Zhixu Wu, Peng Hu, Xin Zhang
      First page: 573
      Abstract: In this paper, using the combined observations of the NOAA 16, LANL-01A, IMAGE satellites, VLF radio wave, and ground-based riometers, we study the fluctuation of lower ionosphere-associated precipitating energetic electrons during a geomagnetic storm on 8 November 2004. Associated with the substorm dispersion injection observed by the LANL-01A satellite, the riometers observed obvious enhancements of ionospheric absorption within the electron isotropic zone, which they attributed to the tail current sheet scattering (TCS) mechanism. Through observations of the NOAA 16 satellite, we found a sharp enhancement of the precipitating electron flux within the anisotropic zone, which entailed an obvious separation of energetic electron precipitation at high latitudes. This energetic electron precipitation within the anisotropic zone leads to the significant enhancement of electron density in the D region, thus resulting in the variations of VLF radio wave amplitudes, which propagate in the middle latitudes. Since the projection of the electron precipitation region within the anisotropic zone is at the inner edge of the plasmapause observed by the IMAGE EUV, the precipitation of energetic electrons should be attributed to the ELF hiss-ring current electron interaction. As a result, the energetic electron precipitations due to the tail current sheet scattering mechanism and wave-particle interaction in the inner magnetosphere were both observed and analyzed as they were associated with a substorm during a geomagnetic storm.
      Citation: Atmosphere
      PubDate: 2021-04-28
      DOI: 10.3390/atmos12050573
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 574: Chemical Characteristics and Sources of
           Water-Soluble Organic Nitrogen Species in PM2.5 in Nanjing, China

    • Authors: Yue Liu, Haiwei Li, Shijie Cui, Dongyang Nie, Yanfang Chen, Xinlei Ge
      First page: 574
      Abstract: Water-soluble organic nitrogen (WSON) is an important component of PM2.5 which may affect air quality, climate and human health. Herein, one-year field samples of atmospheric PM2.5 (June 2017–May 2018) were collected in northern Nanjing. Chemical characterization of PM2.5 major components as well as WSON were conducted, and WSON composition and sources were further investigated via measurements by a Aerodyne soot particle aerosol mass spectrometer (SP-AMS) as well as positive matrix factorization (PMF). Inorganic ions, mainly consisting of ammonium, sulfate, and nitrate, were found to dominate PM2.5 mass (58.7%), followed by organic matter (OM) (22.6%), and elemental carbon (EC) (2.1%). Water-soluble OM dominated OM (65.1%), and its temporal variation was closely correlated with that of secondary organic matter, while time series of water-insoluble OM concentrations correlated tightly with that of primary organic matter. Average WSON concentration was 2.15 μg/m3, which was highest in winter and lowest in summer. Correlation analysis of WSON with PM2.5 components also indicated that WSON was mainly from secondary sources. SP-AMS revealed that WSON mass spectrum was composed of CxHyNp+ (91.2%) and CxHyOzNp+ (8.8%), indicating dominance of amines and other oxygenated ON compounds. PMF analysis resolved two primary sources (traffic, biomass burning) and two secondary sources (less-oxidized and more-oxidized factors) of WSOM and WSON, and the secondary source dominated both WSOM and WSON. Contribution of the more-oxidized ON factor was very high in winter, and the less-oxidized factor was significant in summer, indicating a likely important role of aqueous-phase processing in winter as well as photochemical oxidation in summer to WSON.
      Citation: Atmosphere
      PubDate: 2021-04-28
      DOI: 10.3390/atmos12050574
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 575: Sub-Cloud Secondary Evaporation in
           Precipitation Stable Isotopes Based on the Stewart Model in Yangtze River
           Basin

    • Authors: Hanyu Xiao, Mingjun Zhang, Yu Zhang, Zhihua Huang, Xuyang Yao, Jiaxin Wang, Tingting Han, Pengyan Su
      First page: 575
      Abstract: The stable isotopes (2H, 18O) of precipitation change due to the sub-cloud secondary evaporation during raindrop fall. The study of the temporal and spatial variation of sub-cloud secondary evaporation and its causes by using hydrogen and oxygen stable isotopes is of great significance to the study of the regional water cycle process. Based on the hourly meteorological data of 648 meteorological stations in 17 provinces (cities) of the Yangtze River Basin from March 2018 to February 2019, we analyzed the temporal and spatial characteristics of precipitation excess deuterium variation (Δd) in the region, based on the improved Stewart model. We discuss the various influence factors under different magnitude Δd value change and the impact factor of each partition sub-cloud secondary evaporation influence of the difference. The results show the following: (1) In terms of hourly variation, the sub-cloud secondary evaporation in the daytime is stronger than that at night. In terms of monthly variation, different regions of the study area have different characteristics; that is, the effect of sub-cloud secondary evaporation is more significant in summer and autumn in the northern subtropics and south temperate zones, and in spring and summer in the mid-subtropics and plateau climate zones. (2) There were significant spatial differences in the study area in different seasons, and the effect of sub-cloud secondary evaporation was the most significant in the plateau climate area throughout the year. (3) When the rainfall is 0–5 mm, the temperature is >30 °C, the vapor pressure is <3 hPa, the relative humidity is 50–60%, and the raindrop diameter is 0.5–1 mm; the sub-cloud secondary evaporation effect is the most obvious.
      Citation: Atmosphere
      PubDate: 2021-04-28
      DOI: 10.3390/atmos12050575
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 576: C-Band SAR Winds for Tropical Cyclone
           Monitoring and Forecast in the South-West Indian Ocean

    • Authors: Quoc-Phi Duong, Sébastien Langlade, Christophe Payan, Romain Husson, Alexis Mouche, Sylvie Malardel
      First page: 576
      Abstract: Tropical cyclone (TC) monitoring and forecast in the South West Indian Ocean (SWIO) basin remain challenging, notably because of the lack of direct observations. During the 2018–2019 cyclone season, S-1 Sentinel SAR images were acquired, as part of the ReNovRisk-Cyclone research program, giving access to unprecedented detailed TC wind structure description without wind speed limitation. This paper assesses the quality of these data and the impact of their assimilation for TC forecasts. SAR observations are compared with analyses from a convection-permitting, limited area model AROME OI 3D-Var and with wind products used for operational TC monitoring. Their bias depends on the angle of incidence of the radar and the observation error is larger for extreme wind speed. The impact of SAR assimilation in AROME OI 3D-Var is assessed through two case studies. In the TC GELENA case, it leads to a better TC positioning and an improved representation of inner and outer vortex structures. The TC intensity reduction in the analysis propagates through subsequent analyses and it has an impact on forecasts for around 12 h. In the TC IDAI case, the 3D-Var does not manage to reproduce TC intensity captured by SAR. In both cases, the modification of the initial conditions has little influence on the intensification rate of the model forecasts. Sensitivity tests show that these results are robust to different observation errors and thinning.
      Citation: Atmosphere
      PubDate: 2021-04-29
      DOI: 10.3390/atmos12050576
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 577: Artifact-Free Single Image Defogging

    • Authors: Gabriele Graffieti, Davide Maltoni
      First page: 577
      Abstract: In this paper, we present a novel defogging technique, named CurL-Defog, with the aim of minimizing the insertion of artifacts while maintaining good contrast restoration and visibility enhancement. Many learning-based defogging approaches rely on paired data, where fog is artificially added to clear images; this usually provides good results on mildly fogged images but is not effective for difficult cases. On the other hand, the models trained with real data can produce visually impressive results, but unwanted artifacts are often present. We propose a curriculum learning strategy and an enhanced CycleGAN model to reduce the number of produced artifacts, where both synthetic and real data are used in the training procedure. We also introduce a new metric, called HArD (Hazy Artifact Detector), to numerically quantify the number of artifacts in the defogged images, thus avoiding the tedious and subjective manual inspection of the results. HArD is then combined with other defogging indicators to produce a solid metric that is not deceived by the presence of artifacts. The proposed approach compares favorably with state-of-the-art techniques on both real and synthetic datasets.
      Citation: Atmosphere
      PubDate: 2021-04-29
      DOI: 10.3390/atmos12050577
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 578: Evaluation and Bias Correction of the
           Secondary Inorganic Aerosol Modeling over North China Plain in Autumn and
           Winter

    • Authors: Qian Wu, Xiao Tang, Lei Kong, Xu Dao, Miaomiao Lu, Zirui Liu, Wei Wang, Qian Wang, Duohong Chen, Lin Wu, Xiaole Pan, Jie Li, Jiang Zhu, Zifa Wang
      First page: 578
      Abstract: Secondary inorganic aerosol (SIA) is the key driving factor of fine-particle explosive growth (FPEG) events, which are frequently observed in North China Plain. However, the SIA simulations remain highly uncertain over East Asia. To further investigate this issue, SIA modeling over North China Plain with the 15 km resolution Nested Air Quality Prediction Model System (NAQPMS) was performed from October 2017 to March 2018. Surface observations of SIA at 28 sites were obtained to evaluate the model, which confirmed the biases in the SIA modeling. To identify the source of these biases and reduce them, uncertainty analysis was performed by evaluating the heterogeneous chemical reactions in the model and conducting sensitivity tests on the different reactions. The results suggest that the omission of the SO2 heterogeneous chemical reaction involving anthropogenic aerosols in the model is probably the key reason for the systematic underestimation of sulfate during the winter season. The uptake coefficient of the “renoxification” reaction is a key source of uncertainty in nitrate simulations, and it is likely to be overestimated by the NAQPMS. Consideration of the SO2 heterogeneous reaction involving anthropogenic aerosols and optimization of the uptake coefficient of the “renoxification” reaction in the model suitably reproduced the temporal and spatial variations in sulfate, nitrate and ammonium over North China Plain. The biases in the simulations of sulfate, nitrate, ammonium, and particulate matter smaller than 2.5 μm (PM2.5) were reduced by 84.2%, 54.8%, 81.8%, and 80.9%, respectively. The results of this study provide a reference for the reduction in the model bias of SIA and PM2.5 and improvement of the simulation of heterogeneous chemical processes.
      Citation: Atmosphere
      PubDate: 2021-04-30
      DOI: 10.3390/atmos12050578
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 579: Organic Molecular Tracers in PM2.5 at
           Urban Sites during Spring and Summer in Japan: Impact of Secondary Organic
           Aerosols on Water-Soluble Organic Carbon

    • Authors: Fumikazu Ikemori, Rie Nishimura, Shinji Saito, Masayuki Akiyama, Shigekazu Yamamoto, Akihiro Iijima, Seiji Sugata
      First page: 579
      Abstract: To understand the characteristics of secondary organic aerosols (SOAs) and estimate their impact on water-soluble organic carbon (WSOC) in urban areas in Japan, we measured 17 organic tracers using gas chromatography–mass spectrometry from particulate matter with an aerodynamic diameter smaller than 2.5 μm collected at five urban sites in Japan during spring and summer. Most anthropogenic, monoterpene-derived, and isoprene-derived SOA tracers showed meaningful correlations with potential ozone in both these seasons. These results indicate that oxidants play an important role in SOAs produced during both seasons in urban cities in Japan. WSOC was significantly affected by anthropogenic and monoterpene-derived SOAs during spring and three SOA groups during summer at most of the sites sampled. The total estimated secondary organic carbons (SOCs), including mono-aromatic, di-aromatic, monoterpene-derived, and isoprene-derived SOCs, could explain the WSOC fractions of 39–63% in spring and 46–54% in summer at each site. Notably, monoterpene-derived and mono-aromatic SOCs accounted for most of the total estimated SOCs in both spring (85–93%) and summer (75–82%) at each site. These results indicate that SOAs significantly impact WSOC concentrations during both these seasons at urban sites in Japan.
      Citation: Atmosphere
      PubDate: 2021-04-30
      DOI: 10.3390/atmos12050579
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 580: An Urban Lagrangian Stochastic Dispersion
           Model for Simulating Traffic Particulate-Matter Concentration Fields

    • Authors: Eyal Fattal, Hadas David-Saroussi, Ziv Klausner, Omri Buchman
      First page: 580
      Abstract: The accumulated particulate matter concentration at a given vertical column due to traffic sources in urban area has many important consequences. This task, however, imposes a major challenge, since the problem of realistic pollutant dispersion in an urban environment is a very demanding task, both theoretically and computationally. This is mainly due to the highly inhomogeneous three dimensional turbulent flow regime in the urban canopy roughness sublayer, which is far from “local equilibrium” between shear production and dissipation. We present here a mass-consistent urban Lagrangian stochastic model for pollutants dispersion, where the flow field is modeled using a hybrid approach by which we model the surface layer based on the typical turbulent scales, both of the canopy and in the surface layer inertial sub-layer. In particular it relies on representing the canopy aerodynamically as a porous medium by spatial averaging the equations of motion, with the assumption that the canopy is laterally uniform on a scale much larger than the buildings but smaller than the urban block/neighbourhood, i.e., at the sub-urban-block scale. Choosing the spatial representative averaging volume allows the averaged variables to reflect the characteristic vertical heterogeneity of the canopy but to smooth out smaller scale spatial fluctuations caused as air flows in between the buildings. This modeling approach serves as the base for a realistic and efficient methodology for the calculation of the accumulated concentration from multiple traffic sources for any vertical column in the urban area. The existence of multiple traffic sources impose further difficulty since the computational effort required is very demanding for practical uses. Therefore, footprint analysis screening was introduced to identify the relevant part of the urban area which contributes to the chosen column. All the traffic sources in this footprint area where merged into several areal sources, further used for the evaluation of the concentration profile. This methodology was implemented for four cases in the Tel Aviv metropolitan area based on several selected summer climatological scenarios. We present different typical behaviors, demonstrating combination of source structure, urban morphology, flow characteristics, and the resultant dispersion pattern in each case.
      Citation: Atmosphere
      PubDate: 2021-04-30
      DOI: 10.3390/atmos12050580
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 581: Polarimetric Radar Characteristics of
           Tornadogenesis Failure in Supercell Thunderstorms

    • Authors: Matthew Van Den Broeke
      First page: 581
      Abstract: Many nontornadic supercell storms have times when they appear to be moving toward tornadogenesis, including the development of a strong low-level vortex, but never end up producing a tornado. These tornadogenesis failure (TGF) episodes can be a substantial challenge to operational meteorologists. In this study, a sample of 32 pre-tornadic and 36 pre-TGF supercells is examined in the 30 min pre-tornadogenesis or pre-TGF period to explore the feasibility of using polarimetric radar metrics to highlight storms with larger tornadogenesis potential in the near-term. Overall the results indicate few strong distinguishers of pre-tornadic storms. Differential reflectivity (ZDR) arc size and intensity were the most promising metrics examined, with ZDR arc size potentially exhibiting large enough differences between the two storm subsets to be operationally useful. Change in the radar metrics leading up to tornadogenesis or TGF did not exhibit large differences, though most findings were consistent with hypotheses based on prior findings in the literature.
      Citation: Atmosphere
      PubDate: 2021-04-30
      DOI: 10.3390/atmos12050581
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 582: Analysis of Arctic Spring Ozone Anomaly in
           the Phases of QBO and 11-Year Solar Cycle for 1979–2017

    • Authors: Yousuke Yamashita, Hideharu Akiyoshi, Masaaki Takahashi
      First page: 582
      Abstract: Arctic ozone amount in winter to spring shows large year-to-year variation. This study investigates Arctic spring ozone in relation to the phase of quasi-biennial oscillation (QBO)/the 11-year solar cycle, using satellite observations, reanalysis data, and outputs of a chemistry climate model (CCM) during the period of 1979–2017. For this duration, we found that the composite mean of the Northern Hemisphere high-latitude total ozone in the QBO-westerly (QBO-W)/solar minimum (Smin) phase is slightly smaller than those averaged for the QBO-W/Smax and QBO-E/Smax years in March. An analysis of a passive ozone tracer in the CCM simulation indicates that this negative anomaly is primarily caused by transport. The negative anomaly is consistent with a weakening of the residual mean downward motion in the polar lower stratosphere. The contribution of chemical processes estimated using the column amount difference between ozone and the passive ozone tracer is between 10–20% of the total anomaly in March. The lower ozone levels in the Arctic spring during the QBO-W/Smin years are associated with a stronger Arctic polar vortex from late winter to early spring, which is linked to the reduced occurrence of sudden stratospheric warming in the winter during the QBO-W/Smin years.
      Citation: Atmosphere
      PubDate: 2021-04-30
      DOI: 10.3390/atmos12050582
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 583: Air Quality in Southeast Brazil during
           COVID-19 Lockdown: A Combined Satellite and Ground-Based Data Analysis

    • Authors: Rayssa Brandao, Hosein Foroutan
      First page: 583
      Abstract: With the current COVID-19 pandemic being spread all over the world, lockdown measures are being implemented, making air pollution levels go down in several countries. In this context, the air quality changes in the highly populated and trafficked Brazilian states of São Paulo (SP) and Rio de Janeiro (RJ) were addressed using a combination of satellite and ground-based daily data analysis. We explored nitrogen dioxide (NO2) and fine particulate matter (PM2.5) daily levels for the month of May from 2015–2020. Daily measurements of NO2 column concentrations from the Ozone Monitoring Instrument (OMI) aboard NASA’s Aura satellite were analyzed and decreases of 42% and 49.6% were found for SP and RJ, respectively, during the year 2020 compared to the 2015–2019 average. Besides NO2 column retrievals, ground-based data measured by the Brazilian States Environmental Institutions were analyzed and correlated with satellite retrievals. Correlation coefficients between year-to-year changes in satellite column and ground-based concentrations were 77% and 53% in SP and RJ, respectively. Ground-based data showed 13.3% and 18.8% decrease in NO2 levels for SP and RJ, respectively, in 2020 compared to 2019. In SP, no significant change in PM2.5 was observed in 2020 compared to 2019. To further isolate the effect of emissions reduction due to the lockdown, meteorological data and number of wildfire hotspots were analyzed. NO2 concentrations showed negative and positive correlations with wind speed and temperature, respectively. PM2.5 concentration distributions suggested an influence by the wildfires in the southeast region of the country. Synergistic analyses of satellite retrievals, surface level concentrations, and weather data provide a more complete picture of changes to pollutant levels.
      Citation: Atmosphere
      PubDate: 2021-05-01
      DOI: 10.3390/atmos12050583
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 584: Visual Weather Property Prediction by
           Multi-Task Learning and Two-Dimensional RNNs

    • Authors: Wei-Ta Chu, Yu-Hsuan Liang, Kai-Chia Ho
      First page: 584
      Abstract: We attempted to employ convolutional neural networks to extract visual features and developed recurrent neural networks for weather property estimation using only image data. Four common weather properties are estimated, i.e., temperature, humidity, visibility, and wind speed. Based on the success of previous works on temperature prediction, we extended them in terms of two aspects. First, by considering the effectiveness of deep multi-task learning, we jointly estimated four weather properties on the basis of the same visual information. Second, we propose that weather property estimations considering temporal evolution can be conducted from two perspectives, i.e., day-wise or hour-wise. A two-dimensional recurrent neural network is thus proposed to unify the two perspectives. In the evaluation, we show that better prediction accuracy can be obtained compared to the state-of-the-art models. We believe that the proposed approach is the first visual weather property estimation model trained based on multi-task learning.
      Citation: Atmosphere
      PubDate: 2021-05-01
      DOI: 10.3390/atmos12050584
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 585: Mitigation of Odor and Gaseous Emissions
           from Swine Barn with UV-A and UV-C Photocatalysis

    • Authors: Myeongseong Lee, Jacek A. Koziel, Wyatt Murphy, William S. Jenks, Baitong Chen, Peiyang Li, Chumki Banik
      First page: 585
      Abstract: UV-A (ca. 365 nm wavelength, a.k.a. ‘black light’) photocatalysis has been investigated to comprehensively mitigate odor and selected air pollutants in the livestock environment. This study was conducted to confirm the performance of UV-A photocatalysis on the swine farm. The objectives of this research were to (1) scale-up of the UV-A photocatalysis treatment, (2) evaluate the mitigation of odorous gases from swine slurry pit, (3) test different UV sources, (4) evaluate the effect of particulate matter (PM) and (5) conduct preliminary economic analyses. We tested UV-A photocatalysis at a mobile laboratory-scale capable of treating ~0.2–0.8 m3·s−1 of barn exhaust air. The targeted gaseous emissions of barn exhaust air were significantly mitigated (p < 0.05) up to 40% reduction of measured odor; 63%, 44%, 32%, 40%, 66% and 49% reduction of dimethyl disulfide, isobutyric acid, butanoic acid, p-cresol, indole and skatole, respectively; 40% reduction of H2S; 100% reduction of O3; and 13% reduction of N2O. The PM mitigation effect was not significant. Formaldehyde levels did not change, and a 21% generation of CO2 was observed. The percent reduction of targeted gases decreased as the airborne PM increased. Simultaneous chemical and sensory analysis confirmed that UV-A treatment changed the overall nuisance odor character of swine barn emissions into weaker manure odor with ‘toothpaste and ‘mint’ notes. The smell of benzoic acid generated in UV-A treatment was likely one of the compounds responsible for the less-offensive overall odor character of the UV-treated emissions. Results are needed to inform the design of a farm-scale trial, where the interior barn walls can be treated with the photocatalyst.
      Citation: Atmosphere
      PubDate: 2021-05-01
      DOI: 10.3390/atmos12050585
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 586: Speciation of Magnesium in Aerosols Using
           X-ray Absorption Near-Edge Structure Related to Its Contribution to
           Neutralization Reactions in the Atmosphere

    • Authors: Takahiro Kawai, Yoshiaki Yamakawa, Yoshio Takahashi
      First page: 586
      Abstract: Aerosols, including mineral dust, are transported from China and Mongolia to Japan, particularly in spring. It has been recognized that calcium (Ca) carbonate is the main Ca species in aerosols, which reacts with acidic species such as sulfuric and nitric acids at the surface of mineral dust during its long-range transport, related to mitigation of acid depositions. The similar assumption that magnesium (Mg) originally takes the form of carbonate and contributes to the neutralization reaction and buffering effect on the acidity of aerosols has been suggested in various studies. However, few studies have confirmed this process by measuring actual Mg species in aerosols quantitatively. In this study, X-ray absorption near-edge structure (XANES) spectroscopy was employed to determine Mg species in size-fractionated aerosol samples, including mineral dust. The results showed that (i) most Mg in the mineral dust did not take the form of carbonate and its reacted species (e.g., sulfate and nitrate) produced by the neutralization reaction, but (ii) Mg was mainly found as Mg in the octahedral layer in phyllosilicates. Given that the reactivity of such Mg in phyllosilicates is much lower than those in carbonate minerals, the contribution of Mg to the neutralization reactions in the atmosphere must be lower than previously expected.
      Citation: Atmosphere
      PubDate: 2021-05-01
      DOI: 10.3390/atmos12050586
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 587: Sea Surface Temperature Variability over
           

    • Authors: Sartaj Khan, Shengchun Piao, Guangxue Zheng, Imran Ullah Khan, David Bradley, Shazia Khan, Yang Song
      First page: 587
      Abstract: 2016 and 2017 were marked by strong El Niño and weak La Niña events, respectively, in the tropical East Pacific Ocean. The strong El Niño and weak La Niña events in the Pacific significantly impacted the sea surface temperature (SST) in the tropical Indian Ocean (TIO) and were followed by extreme negative and weak positive Indian Ocean Dipole (IOD) phases in 2016 and 2017, which triggered floods in the Indian subcontinent and drought conditions in East Africa. The IOD is an irregular and periodic oscillation in the Indian Ocean, which has attracted much attention in the last two decades due to its impact on the climate in surrounding landmasses. Much work has been done in the past to investigate global climate change and its impact on the evolution of IOD. The dynamic behind it, however, is still not well understood. The present study, using various satellite datasets, examined and analyzed the dynamics behind these events and their impacts on SST variability in the TIO. For this study, the monthly mean SST data was provided by NOAA Optimum Interpolation Sea Surface Temperature (OISST). SST anomalies were measured on the basis of 30-year mean daily climatology (1981–2010). It was determined that the eastern and western poles of the TIO play quite different roles during the sequence of negative and positive IOD phases. The analysis of air-sea interactions and the relationship between wind and SST suggested that SST is primarily controlled by wind force in the West pole. On the other hand, the high SST that occurred during the negative IOD phase induced local convection and westerly wind anomalies via the Bjerknes feedback mechanism. The strong convection, which was confined to the (warm) eastern equatorial Indian Ocean was accompanied by east–west SST anomalies that drove a series of downwelling Kelvin waves that deepened the thermocline in the east. Another notable feature of this study was its observation of weak upwelling along the Omani–Arabian coast, which warmed the SST by 1 °C in the summer of 2017 (as compared to 2016). This warming led to increased precipitation in the Bay of Bengal (BoB) region during the summer of 2017. The results of the present work will be important for the study of monsoons and may be useful in predicting both droughts and floods in landmasses in the vicinity of the Indian Ocean, especially in the Indian subcontinent and East African regions.
      Citation: Atmosphere
      PubDate: 2021-05-01
      DOI: 10.3390/atmos12050587
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 588: Analysis of Climate Change Projections for
           Mozambique under the Representative Concentration Pathways

    • Authors: Alberto F. Mavume, Bionídio E. Banze, Odete A. Macie, António J. Queface
      First page: 588
      Abstract: Despite having contributed the least to global warming and having the lowest emissions, the African region is the most vulnerable continent to climate change impacts. To reduce the levels of risk arising from climate change, it is mandatory to combine both mitigation and adaptation. While mitigation can reduce global warming, not all impacts can be avoided. Therefore, adaptation is essential to advance strategic interventions and reduce the impacts. As part of the international effort to cope with changing climate, a set of Coordinated Regional Downscaling Experiment (CORDEX) domains have been established worldwide. The CORDEX-Africa initiative has been developed to analyze downscaled regional climate data over the African domain for climate data analysis techniques and engage users of climate information in both sector-specific and region/space-based applications. This study takes outputs of high-resolution climate multi-models from the CORDEX-Africa initiative constructed at a spatial resolution of 50 km to assess climate change projections over Mozambique. Projected spatial and temporal changes (three 30-year time periods, the present (2011-2040), mid (2041-2070), and the end (2071-2100)) in temperature and precipitation under the Representative Concentration Pathways RCP2.6, RCP4.5, and RCP8.5 are analyzed and compared relative to the baseline period (1961-1990). Results show that there is a tendency toward an increase in annual temperature as we move toward the middle and end of the century, mainly for RCP4.5 and RCP8.5 scenarios. This is evident for the Gaza Province, north of the Tete Province, and parts of Niassa Province, where variations will be Tmax (0.92 to 4.73 °C), Tmin (1.12 to 4.85 °C), and Tmean (0.99 to 4.7 °C). In contrast, the coastal region will experience less variation (values < 0.5 °C to 3 °C). At the seasonal scale, the pattern of temperature change does not differ from that of the annual scale. The JJA and SON seasons present the largest variations in temperature compared with DJF and MAM seasons. The increase in temperature may reach 4.47 °C in DJF, 4.59 °C in MAM, 5.04 °C in JJA, and 5.25 °C in SON. Precipitation shows substantial spatial and temporal variations, both in annual and seasonal scales. The northern coastal zone region shows a reduction in precipitation, while the entire southern region, with the exception of the coastal part, shows an increase up to 40% and up to 50% in some parts of the central and northern regions, in future climates for all periods under the three reference scenarios. At the seasonal scale (DJF and MAM), the precipitation in much of Mozambique shows above average precipitation with an increase up to more than 40% under the three scenarios. In contrast, during the JJA season, the three scenarios show a decrease in precipitation. Notably, the interior part will have the largest decrease, reaching a variation of -60% over most of the Gaza, Tete, and Niassa Provinces.
      Citation: Atmosphere
      PubDate: 2021-05-01
      DOI: 10.3390/atmos12050588
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 589: Concentration Fluctuations of Single
           Particle Stochastic Lagrangian Model Assessment with Experimental Field
           Data

    • Authors: Enrico Ferrero, Filippo Maccarini
      First page: 589
      Abstract: A single particle Lagrangian Stochastic model has been developed and applied with the purpose of simulating the concentration fluctuations dispersion. This model treats concentration variance as a quantity whose motion is driven by an advection-diffusion process so that it can be studied by a single particle model. A parameterization for both velocity standard deviations and Lagrangian time-scales is required as input to the model. The paper is focused on the estimation of the best parameterization needed to simulate both mean and standard deviation concentrations in a case study. We consider the FFT-07 field experiment. The trials took place at Dugway Proving Ground, UTAH (USA) and consist of a dispersion analysis of a gas emitted from a point-like source in different atmospheric conditions with a continuous emission technique. The very small spatial scales (a few hundred meters) and short duration (about 10 minutes) that characterize the trials make the comparison with model results very challenging, since traditional boundary layer parameterizations fail in correctly reproducing the turbulent field and, as a consequence, the dispersion simulation yields unsatisfactorily results. We vary the coefficients of the turbulence parameterization to match the small-scale turbulence. Furthermore, we show that the parameterization for the variance dissipation time-scale, already tested in neutral conditions, can be used also in stable and unstable conditions and in low-wind speed conditions. The model gives good results as far as mean concentration is concerned and rather satisfactory results for the concentration standard deviations. Comparison between model results and observation is shown through both statistical and graphical analyses.
      Citation: Atmosphere
      PubDate: 2021-05-01
      DOI: 10.3390/atmos12050589
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 590: Trends in PM2.5 Concentration in Nagoya,
           Japan, from 2003 to 2018 and Impacts of PM2.5 Countermeasures

    • Authors: Makiko Yamagami, Fumikazu Ikemori, Hironori Nakashima, Kunihiro Hisatsune, Kayo Ueda, Shinji Wakamatsu, Kazuo Osada
      First page: 590
      Abstract: In Japan, various countermeasures have been undertaken to reduce the atmospheric concentration of fine particulate matter (PM2.5). We evaluated the extent to which these countermeasures were effective in reducing PM2.5 concentrations by analyzing the long-term concentration trends of the major components of PM2.5 and their emissions in Nagoya City. PM2.5 concentrations decreased by 53% over the 16-year period from fiscal years 2003 to 2018 in Nagoya City. Elemental carbon (EC) was the component of PM2.5 with the greatest decrease in concentration over the 16 years, decreasing by 4.3 μg/m3, followed by SO42− (3.0 μg/m3), organic carbon (OC) (2.0 μg/m3), NH4+ (1.6 μg/m3), and NO3− (1.3 μg/m3). The decrease in EC concentration was found to be caused largely by the effect of diesel emission control. OC concentrations decreased because of the effects of volatile organic compound (VOC) emission regulations for stationary sources and reductions in VOCs emitted by vehicles and construction machinery. NO3− concentrations decreased alongside decreased contributions from vehicles, construction machinery, and stationary sources, in descending order of the magnitude of decrease. Although these findings identify some source control measures that have been effective in reducing PM2.5, they also reveal the ineffectiveness of some recent countermeasures for various components, such as those targeting OC concentrations.
      Citation: Atmosphere
      PubDate: 2021-05-01
      DOI: 10.3390/atmos12050590
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 591: On the u☆-U Relationship in the Stable
           Atmospheric Boundary Layer over Arctic Sea Ice

    • Authors: Dmitry Chechin
      First page: 591
      Abstract: A relationship between the friction velocity u☆ and mean wind speed U in a stable atmospheric boundary layer (ABL) over Arctic sea ice was considered. To that aim, the observations collected during the Surface Heat Budget of the Arctic Ocean (SHEBA) experiment were used. The observations showed the so-called “hockey-stick” shape of the u☆−U relationship, which consists of a slow increase of u☆ with increasing wind speed for U<Utr and a more rapid almost linear increase of u☆ for U>Utr, where Utr is the wind speed of transition between the two regimes. Such a relationship is most pronounced at the highest observational levels, namely at 9 and 14 m, and is also sharper when the air-surface temperature difference exceeds its average values for stable conditions. It is shown that the Monin–Obukhov similarity theory (MOST) reproduces the observed u☆−U relationship rather well. This suggests that at least for the SHEBA dataset, there is no contradiction between MOST and the “hockey-stick” shape of the u☆−U relationship. However, the SHEBA data, as well as the single-column simulations show that for cases with strong stability, u☆ significantly decreases with height due to the shallowness of the ABL. It was shown that when u☆ was assumed independent of height, the value of the normalized drag coefficient, i.e., of the so-called stability correction function for momentum, calculated using observations at a certain level, can be significantly underestimated. To overcome this, the decrease of u☆ with height was taken into account in the framework of MOST using local scaling instead of the scaling with surface fluxes. Using such an extended MOST brought the estimates of the normalized drag coefficient closer to the Businger–Dyer relation.
      Citation: Atmosphere
      PubDate: 2021-05-02
      DOI: 10.3390/atmos12050591
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 592: A Multimethod Analysis for Average Annual
           

    • Authors: Mehdi Aalijahan, Azra Khosravichenar
      First page: 592
      Abstract: The spatial distribution of precipitation is one of the most important climatic variables used in geographic and environmental studies. However, when there is a lack of full coverage of meteorological stations, precipitation estimations are necessary to interpolate precipitation for larger areas. The purpose of this research was to find the best interpolation method for precipitation mapping in the partly densely populated Khorasan Razavi province of northeastern Iran. To achieve this, we compared five methods by applying average precipitation data from 97 rain gauge stations in that province for a period of 20 years (1994–2014): Inverse Distance Weighting, Radial Basis Functions (Completely Regularized Spline, Spline with Tension, Multiquadric, Inverse Multiquadric, Thin Plate Spline), Kriging (Simple, Ordinary, Universal), Co-Kriging (Simple, Ordinary, Universal) with an auxiliary elevation parameter, and non-linear Regression. Root Mean Square Error (RMSE), Mean Absolute Error (MAE), and the Coefficient of Determination (R2) were used to determine the best-performing method of precipitation interpolation. Our study shows that Ordinary Co-Kriging with an auxiliary elevation parameter was the best method for determining the distribution of annual precipitation for this region, showing the highest coefficient of determination of 0.46% between estimated and observed values. Therefore, the application of this method of precipitation mapping would form a mandatory base for regional planning and policy making in the arid to semi-arid Khorasan Razavi province during the future.
      Citation: Atmosphere
      PubDate: 2021-05-02
      DOI: 10.3390/atmos12050592
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 593: Evaluating the NDVI–Rainfall
           Relationship in Bisha Watershed, Saudi Arabia Using Non-Stationary
           Modeling Technique

    • Authors: Javed Mallick, Mohammed K. AlMesfer, Vijay P. Singh, Ibrahim I. Falqi, Chander Kumar Singh, Majed Alsubih, Nabil Ben Kahla
      First page: 593
      Abstract: The Normalized Difference Vegetation Index (NDVI) and rainfall data were used to model the spatial relationship between vegetation and rainfall. Their correlation in previous studies was typically based on a global regression model, which assumed that the correlation was constant across space. The NDVI–rainfall association, on the other hand, is spatially non-stationary, non-linear, scale-dependent, and influenced by local factors (e.g., soil background). In this study, two statistical methods are used in the modeling, i.e., traditional ordinary least squares (OLS) regression and geographically weighted regression (GWR), to evaluate the NDVI–rainfall relationship. The GWR was implemented annually in the growing seasons of 2000 and 2016, using climate data (Normalized Vegetation Difference Index and rainfall). The NDVI–rainfall relationship in the studied Bisha watershed (an eco-sensitive zone with a complex landscape) was found to have a stable operating scale of around 12 km. The findings support the hypothesis that the OLS model’s average impression could not accurately represent local conditions. By addressing spatial non-stationarity, the GWR approach greatly improves the model’s accuracy and predictive ability. In analyzing the relationship between NDVI patterns and rainfall, our research has shown that GWR outperforms a global OLS model. This superiority stems primarily from the consideration of the relationship’s spatial variance across the study area. Global regression techniques such as OLS can overlook local details, implying that a large portion of the variance in NDVI is unexplained. It appears that rainfall is the most significant factor in deciding the distribution of vegetation in these regions. Furthermore, rainfall had weak relationships with areas predominantly located around wetlands, suggesting the need for additional factors to describe NDVI variations. The GWR method performed better in terms of accuracy, predictive power, and reduced residual autocorrelation. Thus, GWR is recommended as an explanatory and exploratory technique when relations between variables are subject to spatial variability. Since the GWR is a local form of spatial analysis that aligned to local conditions, it has the potential for more accurate prediction; however, a larger amount of data is needed to allow a reliable local fitting.
      Citation: Atmosphere
      PubDate: 2021-05-02
      DOI: 10.3390/atmos12050593
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 594: Understanding Climate Change and Drought
           Perceptions, Impact and Responses in the Rural Savannah, West Africa

    • Authors: Stephen Adaawen
      First page: 594
      Abstract: Rural communities in West Africa have long adopted a variety of coping and adaptation strategies to periods of climate variability and risks. These strategies have mostly been shaped by prevailing indigenous knowledge systems and shared understandings of the underlying causes of climate events. Despite the increasing scientific and policy attention to climate perceptions and integration of indigenous knowledge in climate governance, there is still a lag in going further to probe and consider the socio-cultural and cognitive systems that shape local appreciation of climate change risks and responses. Based largely on qualitative interviews, and complementary household surveys, the paper draws on the concepts of ‘mental’ and ‘cognised’ models to examine drought and climate change risk perceptions and responses in the rural savannah of North-eastern Ghana. Local farmers generally allude to changes in rainfall patterns and prolonged intra-seasonal dry spells. Based on subscriptions to local models of blame in explaining climate risks and impacts, it is also seen that prevailing socio-cultural beliefs and understandings of environmental events tend to inform the responses of farmers in addressing these perceived risks and impacts. The paper advocates for ongoing climate action and policy processes to consider the complexity of different actors and context (socio-cultural, institutional, power structures) in enhancing sustainable adaptation and mitigation measures in vulnerable rural communities.
      Citation: Atmosphere
      PubDate: 2021-05-03
      DOI: 10.3390/atmos12050594
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 595: High-Resolution Assessment of Air Quality
           in Urban Areas—A Business Model Perspective

    • Authors: Klaus Schäfer, Kristian Lande, Hans Grimm, Guido Jenniskens, Roel Gijsbers, Volker Ziegler, Marcus Hank, Matthias Budde
      First page: 595
      Abstract: The increasing availability of low-cost air quality sensors has led to novel sensing approaches. Distributed networks of low-cost sensors, together with data fusion and analytics, have enabled unprecedented, spatiotemporal resolution when observing the urban atmosphere. Several projects have demonstrated the potential of different approaches for high-resolution measurement networks ranging from static, low-cost sensor networks over vehicular and airborne sensing to crowdsourced measurements as well as ranging from a research-based operation to citizen science. Yet, sustaining the operation of such low-cost air quality sensor networks remains challenging because of the lack of regulatory support and the lack of an organizational framework linking these measurements to the official air quality network. This paper discusses the logical inclusion of lower-cost air quality sensors into the existing air quality network via a dynamic field calibration process, the resulting sustainable business models, and how this expansion can be self-funded.
      Citation: Atmosphere
      PubDate: 2021-05-03
      DOI: 10.3390/atmos12050595
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 596: Hepatotoxicity Caused by Repeated and
           Subchronic Pulmonary Exposure to Low-Level Vinyl Chloride in Mice

    • Authors: Chang, Lee, Yuan, Chang, Chang, Lee, Ho, Chuang
      First page: 596
      Abstract: Vinyl chloride (VC) is classified as a group 1 carcinogen to humans by the International Agency for Research on Cancer, and inhalation is considered to be an important route of occupational exposure. In addition, increasing numbers of studies have observed adverse health effects in people living in the vicinity of petrochemical complexes. The objective of this study was to investigate the adverse in vivo health effects on the lungs and liver caused by pulmonary exposure to low-level VC. BALB/c mice were repeatedly intranasally administrated 50 µl/mouse VC at 0, 1, and 200 ng/mL (5 days/week) for 1, 2, and 3 weeks. We observed that exposure to 1 and 200 ng/mL VC significantly increased the tidal volume (μL). Dynamic compliance (mL/cmH2O) significantly decreased after exposure to 200 ng/mL VC for 3 weeks. Total protein, lactate dehydrogenase (LDH), and interleukin (IL)-6 levels in bronchoalveolar lavage fluid (BALF) significantly increased after exposure to 200 ng/mL VC for 2 and/or 3 weeks. Significant decreases in 8-isoprostane and caspase-3 and an increase in IL-6 in the lungs were found after VC exposure for 2 and/or 3 weeks. We observed that aspartate aminotransferase (AST), alkaline phosphatase (ALKP), albumin (ALB), and globulin (GLOB) had significantly increased after three weeks of VC exposure, whereas the ALB/GLOB ratio had significantly decreased after 3 weeks of exposure to VC. IL-6 in the liver increased after exposure to 1 ng/mL VC, but decreased after exposure to 200 ng/mL. IL-1β in the liver significantly decreased following exposure to 200 ng/mL VC, whereas tumor necrosis factor (TNF)-α and caspase-3 significantly increased. Hepatic inflammatory infiltration was confirmed by histological observations. In conclusion, sub-chronic and repeated exposure to low levels of VC can cause lung and liver toxicity in vivo. Attention should be paid to all situations where humans are frequently exposed to elevated VC levels such as workplaces or residents living in the vicinity of petrochemical complexes.
      Citation: Atmosphere
      PubDate: 2021-05-04
      DOI: 10.3390/atmos12050596
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 597: Winter Persistent Extreme Cold Events in
           Xinjiang Region and Their Associations with the Quasi-Biweekly Oscillation
           of the Polar Front Jet

    • Authors: Jie Jiang, Suxiang Yao
      First page: 597
      Abstract: Winter persistent extreme cold events (WPECEs) often cause great damage to the development of economies and people’s lives. The sub-seasonal variation of the atmospheric circulation is regarded as one of important causes of extreme weather, and is key to propel the extended period prediction. In this paper, we mainly analyze the WPECEs in Xinjiang region and their relationship with the sub-seasonal variation of the East Asian polar front jet (PFJ). The results suggest the persistent extreme cold event (equal or greater than 7 days) occurs most frequently in Xinhe County of Xinjiang region, with obvious inter-annual and inter-decadal variations. Further analysis shows that the variation of the mean temperature in the key area has characteristics of intra-seasonal variation when the WPECE occurs. The result of composite analysis shows that this intra-seasonal variation is related to the sub-seasonal variation of atmospheric circulation, especially the PFJ anomalous activity near Lake Balkhash. By using the power spectrum analysis method, note that the PFJ activity has the characteristics of quasi-biweekly oscillation (QBWO) in WPECEs. On quasi-biweekly scale (10–20-day filtered), the weakening of PFJ, the intensification of the zonal easterly wind in the upper troposphere, the accumulation of the strong cold air, and the intensification of the meridional northerly wind in the lower troposphere enhance the occurrence of WPECEs in Xinjiang. Further investigation indicates that the quasi-biweekly PFJ mainly propagates eastward and southward before the WPECE occurs in Xinjiang, China.
      Citation: Atmosphere
      PubDate: 2021-05-05
      DOI: 10.3390/atmos12050597
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 598: Characterization of Pollutant Emissions
           from Typical Material Handling Equipment Using a Portable Emission
           Measurement System

    • Authors: Kaili Pang, Xiangrui Meng, Shuai Ma, Ziyuan Yin
      First page: 598
      Abstract: Non-road equipment has been an important source of pollutants that negatively affect air quality in China. An accurate emission inventory for non-road equipment is therefore required to improve air quality. The objective of this paper was to characterize emissions from typical diesel-fueled material handling equipment (loaders and cranes) using a portable emission measurement system. Instantaneous, modal, and composite emissions were quantified in this study. Three duty modes (idling, moving, and working) were used. Composite emission factors were estimated using modal emissions and time-fractions for typical duty cycles. Results showed that emissions from loaders and cranes were higher and more variable for the moving and working modes than the idling mode. The estimated fuel-based CO, HC, NO, and PM2.5 composite emission factors were 21.7, 2.7, 38.2, and 3.6 g/(kg-fuel), respectively, for loaders, and 8.7, 2.4, 28.3, and 0.3 g/(kg-fuel), respectively, for cranes. NO emissions were highest and should be the main focus for emission controls. CO, HC, NO, and PM2.5 emissions measured were different from emission factors in the US Environmental Protection Agency NONROAD model and the Chinese National Guideline for Emission Inventory Development for Non-Road Equipment. This indicates that improving emission inventory accuracy for non-road equipment requires more real-world emission measurements.
      Citation: Atmosphere
      PubDate: 2021-05-05
      DOI: 10.3390/atmos12050598
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 599: Temperature Response to Changes in
           Vegetation Fraction Cover in a Regional Climate Model

    • Authors: Jose Manuel Jiménez-Gutiérrez, Francisco Valero, Jesús Ruiz-Martínez, Juan Pedro Montávez
      First page: 599
      Abstract: Vegetation plays a key role in partitioning energy at the surface. Meteorological and Climate Models, both global and regional, implement vegetation using two parameters, the vegetation fraction and the leaf area index, obtained from satellite data. In most cases, models use average values for a given period. However, the vegetation is subject to strong inter-annual variability. In this work, the sensitivity of the near surface air temperature to changes in the vegetation is analyzed using a regional climate model (RCM) over the Iberian Peninsula. The experiments have been designed in a way that facilitates the physical interpretation of the results. Results show that the temperature sensitivity to vegetation depends on the time of year and the time of day. Minimum temperatures are always lower when vegetation is increased; this is due to the lower availability of heat in the ground due to the reduction of thermal conductivity. Regarding maximum temperatures, the role of increasing vegetation depends on the available moisture in the soil. In the case of hydric stress, the maximum temperatures increase, and otherwise decrease. In general, increasing vegetation will lead to a higher daily temperature range, since the decrease in minimum temperature is always greater than the decrease for maximum temperature. These results show the importance of having a good estimate of the vegetation parameters as well as the implications that vegetation changes due to natural or anthropogenic causes might have in regional climate for present and climate change projections.
      Citation: Atmosphere
      PubDate: 2021-05-05
      DOI: 10.3390/atmos12050599
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 600: Numerical Study on the Plume Behavior of
           Multiple Stacks of Container Ships

    • Authors: Yine Xu, Qi Yu, Yan Zhang, Weichun Ma
      First page: 600
      Abstract: This paper showed different plume behaviors of exhausts from different number of stacks of the container ship, using CFD code PHOENICS version 6.0. The plume behavior was quantitatively analyzed by mass fraction of the pollutant in the exhaust and plume heights. Three simplified typical configurations were constructed by CFD according to the investigation of container ships. The configurations included a single main stack (BL1), one main stack and multiple auxiliary stacks (BL2), and two main stacks and multiple auxiliary stacks (BL3). All the main stacks had the same emission characteristics, and all the auxiliary stacks had the same emission characteristics. The results show that the transmission and diffusion characteristics of the exhaust from multiple stacks are different from those of the exhaust from a single stack. In BL2 and BL3 simulations, the maximum mass fraction of SO2 in the exhaust (C1max) of multiple stack emissions was approximately 329% and 269% higher than that of single stack emissions over the main stack, respectively, and the plume height of multiple stack emissions is higher than that of single stack emissions. In BL2 and BL3 simulations, the plume height of multiple stack emissions was 41% and 75% higher than that of single stack emissions, respectively. The increase of C1max, due to multiple stack emissions, is weakened as the distance of the stacks increase. The difference in plume behavior between multiple stack emissions and single stack emissions is of great significance for air quality management and pollution control in port areas.
      Citation: Atmosphere
      PubDate: 2021-05-05
      DOI: 10.3390/atmos12050600
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 601: Characteristics of Particle Size
           Distributions of Falling Volcanic Ash Measured by Optical Disdrometers at
           the Sakurajima Volcano, Japan

    • Authors: Masayuki Maki, Ren Takaoka, Masato Iguchi
      First page: 601
      Abstract: In the present study, we analyzed the particle size distribution (PSD) of falling volcanic ash particles measured using optical disdrometers during six explosive eruptions of the Sakurajima volcano in Kagoshima Prefecture, Japan. Assuming the gamma PSD model, which is commonly used in radar meteorology, we examined the relationships between each of the gamma PSD parameters (the intercept parameter, the slope parameter, and the shape parameter) calculated by the complete moment method. It was shown that there were good correlations between each of the gamma PSD parameters, which might be one of the characteristics of falling volcanic ash particles. We found from the normalized gamma PSD analysis that the normalized intercept parameter and mass-weighted mean diameter are suitable for estimating the ash fall rate. We also derived empirical power law relationships between pairs of integrated PSD parameters: the ash fall rate, the volcanic ash mass concentration, the reflectivity factor, and the total number of ash particles per unit volume. The results of the present study provide essential information for studying microphysical processes in volcanic ash clouds, developing a method for quantitative ash fall estimation using weather radar, and improving ash transport and sedimentation models.
      Citation: Atmosphere
      PubDate: 2021-05-06
      DOI: 10.3390/atmos12050601
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 602: Observation of the Ionosphere in Middle
           Latitudes during 2009, 2018 and 2018/2019 Sudden Stratospheric Warming
           Events

    • Authors: Zbyšek Mošna, Ilya Edemskiy, Jan Laštovička, Michal Kozubek, Petra Koucká Knížová, Daniel Kouba, Tarique Adnan Siddiqui
      First page: 602
      Abstract: The ionospheric weather is affected not only from above by the Sun but also from below by processes in the lower-lying atmospheric layers. One of the most pronounced atmospheric phenomena is the sudden stratospheric warming (SSW). Three major SSW events from the periods of very low solar activity during January 2009, February 2018, and December 2018/January 2019 were studied to evaluate this effect of the neutral atmosphere on the thermosphere and the ionosphere. The main question is to what extent the ionosphere responds to the SSW events with focus on middle latitudes over Europe. The source of the ionospheric data was ground-based measurements by Digisondes, and the total electron content (TEC). In all three events, the ionospheric response was demonstrated as an increase in electron density around the peak height of the F2 region, in TEC, and presence of wave activity. We presume that neutral atmosphere forcing and geomagnetic activity contributed differently in individual events. The ionospheric response during SSW 2009 was predominantly influenced by the neutral lower atmosphere. The ionospheric changes observed during 2018 and 2018/2019 SSWs are a combination of both geomagnetic and SSW forcing. The ionospheric response to geomagnetic forcing was noticeably lower during time intervals outside of SSWs.
      Citation: Atmosphere
      PubDate: 2021-05-06
      DOI: 10.3390/atmos12050602
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 603: Feasibility of Calculating Standardized
           Precipitation Index with Short-Term Precipitation Data in China

    • Authors: Dongdong Zuo, Wei Hou, Hao Wu, Pengcheng Yan, Qiang Zhang
      First page: 603
      Abstract: At present, high-resolution drought indices are scarce, and this problem has restricted the development of refined drought analysis to some extent. This study explored the possibility of calculating the standardized precipitation index (SPI) with short-term precipitation sequences in China, based on data from 2416 precipitation observation stations covering the time period from 1961 to 2019. The result shows that it is feasible for short-sequence stations to calculate SPI index, based on the spatial interpolation of the precipitation distribution parameters of the long-sequence station. Error analysis denoted that the SPI error was small in east China and large in west China, and the SPI was more accurate when the observation stations were denser. The SPI error of short-sequence sites was mostly less than 0.2 in most areas of eastern China and the consistency rate for the drought categories was larger than 80%, which was lower than the error using the 30-year precipitation samples. Further analysis showed that the estimation error of the distribution parameters β and q was the most important cause of SPI error. Two drought monitoring examples show that the SPI of more than 50,000 short-sequence sites can correctly express the spatial distribution of dry and wet and have refined spatial structure characteristics.
      Citation: Atmosphere
      PubDate: 2021-05-06
      DOI: 10.3390/atmos12050603
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 604: Assessment of a Fusion Sea Surface
           Temperature Product for Numerical Weather Predictions in China: A Case
           Study

    • Authors: Ping Qu, Wei Wang, Zhijie Liu, Xiaoqing Gong, Chunxiang Shi, Bin Xu
      First page: 604
      Abstract: A common approach used for multi-source observation data blending is the fusion method. This study assesses the applicability of the first-generation fusion sea surface temperature (SST) product of the China Meteorological Administration (CMA) in the Yellow–Bohai Sea region for numerical weather predictions. First, daily and 6 h fusion SST measurements are compared with data derived from 21 buoy sites for 2019 to 2020. The error analysis results show that the root-mean-square error (RMSE) of the daily SST ranges from 0.64 to 1.36 °C (overall RMSE of 0.996 °C). The RMSE of the 6 h SST varies from 0.64 to 1.73 °C (overall RMSE of 1.06 °C). According to the simulation result, the SST difference could affect the value and location distribution of liquid water content in the fog area. A lower SST is favorable for increasing the liquid water content, which fits the mechanisms of advection fog formation by warm air flowing over colder water.
      Citation: Atmosphere
      PubDate: 2021-05-06
      DOI: 10.3390/atmos12050604
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 605: Tourism Climatology: Past, Present, and
           Future

    • Authors: María Belén Gómez-Martín
      First page: 605
      Abstract: This special issue, entitled Tourism Climatology: Past, Present, and Future, contains seven original articles and two review reports which tackle some of the main lines of research in the field of Tourism Climatology [...]
      Citation: Atmosphere
      PubDate: 2021-05-06
      DOI: 10.3390/atmos12050605
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 606: Aerosol and Cloud Detection Using Machine
           Learning Algorithms and Space-Based Lidar Data

    • Authors: John E. Yorks, Patrick A. Selmer, Andrew Kupchock, Edward P. Nowottnick, Kenneth E. Christian, Daniel Rusinek, Natasha Dacic, Matthew J. McGill
      First page: 606
      Abstract: Clouds and aerosols play a significant role in determining the overall atmospheric radiation budget, yet remain a key uncertainty in understanding and predicting the future climate system. In addition to their impact on the Earth’s climate system, aerosols from volcanic eruptions, wildfires, man-made pollution events and dust storms are hazardous to aviation safety and human health. Space-based lidar systems provide critical information about the vertical distributions of clouds and aerosols that greatly improve our understanding of the climate system. However, daytime data from backscatter lidars, such as the Cloud-Aerosol Transport System (CATS) on the International Space Station (ISS), must be averaged during science processing at the expense of spatial resolution to obtain sufficient signal-to-noise ratio (SNR) for accurately detecting atmospheric features. For example, 50% of all atmospheric features reported in daytime operational CATS data products require averaging to 60 km for detection. Furthermore, the single-wavelength nature of the CATS primary operation mode makes accurately typing these features challenging in complex scenes. This paper presents machine learning (ML) techniques that, when applied to CATS data, (1) increased the 1064 nm SNR by 75%, (2) increased the number of layers detected (any resolution) by 30%, and (3) enabled detection of 40% more atmospheric features during daytime operations at a horizontal resolution of 5 km compared to the 60 km horizontal resolution often required for daytime CATS operational data products. A Convolutional Neural Network (CNN) trained using CATS standard data products also demonstrated the potential for improved cloud-aerosol discrimination compared to the operational CATS algorithms for cloud edges and complex near-surface scenes during daytime.
      Citation: Atmosphere
      PubDate: 2021-05-07
      DOI: 10.3390/atmos12050606
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 607: Atmospheric PM2.5 Prediction Based on
           Multiple Model Adaptive Unscented Kalman Filter

    • Authors: Jihan Li, Xiaoli Li, Kang Wang, Guimei Cui
      First page: 607
      Abstract: The PM2.5 concentration model is the key to predict PM2.5 concentration. During the prediction of atmospheric PM2.5 concentration based on prediction model, the prediction model of PM2.5 concentration cannot be usually accurately described. For the PM2.5 concentration model in the same period, the dynamic characteristics of the model will change under the influence of many factors. Similarly, for different time periods, the corresponding models of PM2.5 concentration may be different, and the single model cannot play the corresponding ability to predict PM2.5 concentration. The single model leads to the decline of prediction accuracy. To improve the accuracy of PM2.5 concentration prediction in this solution, a multiple model adaptive unscented Kalman filter (MMAUKF) method is proposed in this paper. Firstly, the PM2.5 concentration data in three time periods of the day are taken as the research object, the nonlinear state space model frame of a support vector regression (SVR) method is established. Secondly, the frame of the SVR model in three time periods is combined with an adaptive unscented Kalman filter (AUKF) to predict PM2.5 concentration in the next hour, respectively. Then, the predicted value of three time periods is fused into the final predicted PM2.5 concentration by Bayesian weighting method. Finally, the proposed method is compared with the single support vector regression-adaptive unscented Kalman filter (SVR-AUKF), autoregressive model-Kalman (AR-Kalman), autoregressive model (AR) and back propagation neural network (BP). The prediction results show that the accuracy of PM2.5 concentration prediction is improved in whole time period.
      Citation: Atmosphere
      PubDate: 2021-05-07
      DOI: 10.3390/atmos12050607
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 608: Measurement of Aerodynamic Characteristics
           Using Cinder Models through Free Fall Experiment

    • Authors: Meizhi Liu, Takashi Maruyama, Kansuke Sasaki, Minoru Inoue, Masato Iguchi, Eisuke Fujita
      First page: 608
      Abstract: Rocks ejected from a volcanic eruption often cause loss of lives and structures. Aerodynamic characteristics are needed for evaluating motions of volcanic rocks for the reduction of damage. Falling motions of volcanic rock were measured by using models imitated the configuration of cinders collected at the site of the experiment, Sakurajima volcano. Two types, one with sharp edges and one without sharp edges, were selected as representative of cinder and a sphere was selected as reference model. The falling motions of the models dropped down from a drone were recorded by video camera and a stand-alone measuring system that included a pressure sensor, acceleration and angular velocity sensors in the models. The motion, posture, velocity and acceleration of the model were obtained in order to measure the three-dimensional falling trajectory. The drag and the deviation angle between relative wind direction and wind force direction were examined. The variation of the drag coefficient and the deviation angle with Reynolds number was clarified.
      Citation: Atmosphere
      PubDate: 2021-05-07
      DOI: 10.3390/atmos12050608
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 609: A Spatio-Temporal Visualization Approach
           of PM10 Concentration Data in Metropolitan Lima

    • Authors: Alexandra Abigail Encalada-Malca, Javier David Cochachi-Bustamante, Paulo Canas Rodrigues, Rodrigo Salas, Javier Linkolk López-Gonzales
      First page: 609
      Abstract: Lima is considered one of the cities with the highest air pollution in Latin America. Institutions such as DIGESA, PROTRANSPORTE and SENAMHI are in charge of permanently monitoring air quality; therefore, the air quality visualization system must manage large amounts of data of different concentrations. In this study, a spatio-temporal visualization approach was developed for the exploration of data of the PM10 concentration in Metropolitan Lima, where the spatial behavior, at different time scales, of hourly concentrations of PM10 are analyzed using basic and specialized charts. The results show that the stations located to the east side of the metropolitan area had the highest concentrations, in contrast to the stations located in the center and north that reported better air quality. According to the temporal variation, the station with the highest average of biannual and annual PM10 was the HCH station. The highest PM10 concentrations were registered in 2018, during the summer, highlighting the month of March with daily averages that reached 435 μμg/m3. During the study period, the CRB was the station that recorded the lowest concentrations and the only one that met the Environmental Quality Standard for air quality. The proposed approach exposes a sequence of steps for the elaboration of charts with increasingly specific time periods according to their relevance, and a statistical analysis, such as the dynamic temporal correlation, that allows to obtain a detailed visualization of the spatio-temporal variations of PM10 concentrations. Furthermore, it was concluded that the meteorological variables do not indicate a causal relationship with respect to PM10 levels, but rather that the concentrations of particulate material are related to the urban characteristics of each district.
      Citation: Atmosphere
      PubDate: 2021-05-07
      DOI: 10.3390/atmos12050609
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 610: Nocturnal Boundary Layer Evolution and Its
           Impacts on the Vertical Distributions of Pollutant Particulate Matter

    • Authors: Yu Shi, Lei Liu, Fei Hu, Guangqiang Fan, Juntao Huo
      First page: 610
      Abstract: To investigate the evolution of the nocturnal boundary layer (NBL) and its impacts on the vertical distributions of pollutant particulates, a combination of in situ observations from a large tethered balloon, remote sensing instruments (aerosol lidar and Doppler wind lidar) and an atmospheric environment-monitoring vehicle were utilized. The observation site was approximately 100 km southwest of Beijing, the capital of China. Results show that a considerable proportion of pollutant particulates were still suspended in the residual layer (RL) (e.g., the nitrate concentration reached 30 μg m−3) after sunset. The NBL height calculated by the aerosol lidar was closer to the top of the RL before midnight because of the pollutants stored aloft in the RL and the shallow surface inversion layer; after midnight, the NBL height was more consistent with the top of the surface inversion layer. As the convective mixing layer gradually became established after sunrise the following day, the pollutants stored in the nocturnal RL of the preceding night were entrained downward into the mixing layer. The early morning PM2.5 concentration near 700 m in the RL on 20 December decreased by 83% compared with the concentration at 13:34 on 20 December at the same height. The nitrate concentration also decreased significantly in the RL, and the mixing down of nitrate from the RL could contribute about 37% to the nitrate in the mixing layer. Turbulence activities still existed in the RL with the bulk Richardson number (Rb) below the threshold value. The corresponding increase in PM2.5 was likely to be correlated with the weak turbulence in the RL in the early morning.
      Citation: Atmosphere
      PubDate: 2021-05-07
      DOI: 10.3390/atmos12050610
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 611: Mass Concentration, Chemical Composition,
           and Source Characteristics of PM2.5 in a Plateau Slope City in Southwest
           China

    • Authors: Jianwu Shi, Yinchuan Feng, Liang Ren, Xiuqing Lu, Yaoqian Zhong, Xinyu Han, Ping Ning
      First page: 611
      Abstract: In order to investigate the seasonal variations in the chemical characteristics of PM2.5 at the plateau slope of a mountain city in southwest China, 178 PM2.5 filters (89 quartz and 89 Teflon samples for PM2.5) were collected to sample the urban air of Wenshan in spring and autumn 2016 at three sites. The mass concentrations, water-soluble inorganic ions, organic and inorganic carbon concentrations, and inorganic elements constituting PM2.5 were determined, principal component analysis was used to identify potential sources of PM2.5, and the backward trajectory model was used to calculate the contribution of the long-distance transmission of air particles to the Wenshan area. The average concentration of PM2.5 in spring and autumn was 44.85 ± 10.99 μg/m3. Secondary inorganic aerosols contributed 21.82% and 16.50% of the total PM2.5 in spring and autumn, respectively. The daily mean value of OC/EC indicated that the measured SOC content was generated by the photochemical processes active during the sampling days. However, elements from anthropogenic sources (Ti, Si, Ca, Fe, Al, K, Mg, Na, Sb, Zn, P, Pb, Mn, As and Cu) accounted for 99.38% and 99.24% of the total inorganic elements in spring and autumn, respectively. Finally, source apportionment showed that SIA, dust, industry, biomass burning, motor vehicle emissions and copper smelting emissions constituted the major components in Wenshan. This study is the first to investigate the chemical characterizations and sources of PM2.5 in Wenshan, and it provides effective support for local governments formulating air pollution control policies.
      Citation: Atmosphere
      PubDate: 2021-05-08
      DOI: 10.3390/atmos12050611
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 612: Seasonal Variability of Trends in Regional
           Hot and Warm Temperature Extremes in Europe

    • Authors: Agnieszka Sulikowska, Agnieszka Wypych
      First page: 612
      Abstract: Extremely hot or warm weather over the course of the year may have significant impacts on many aspects of human life, the economy, and the natural environment. Until now a thorough assessment of changes of extreme heat or warm events in Europe was hindered by the number of metrics employed, time periods examined, and most studies being conducted in the summer season only. Here, we employ the Extremity Index (EI) to investigate long-term trends in extremely hot or warm days in Europe over the course of the year, with a special focus on their frequency, spatial extent, and intensity. An extreme temperature event (ETE) is defined as a day with an unusually high temperature for a given location and season, even if such a temperature would not be considered extremely high in an absolute sense. The research is conducted in five spatial domains that together cover a large portion of Europe. The period of the most recent 70 years is considered. In all examined regions, mainly significant increasing trends since 1950 are evident for seasonal EI; therefore, also for ETE frequency, intensity, and spatial range. Yet, every region is characterized by its own event pattern, and trends across the continent strongly vary geographically and seasonally. Our study highlights that examined trends of temperature extremes are accelerating and in the last 40 years the rate of change has been even more than three times greater than in the entire study period. The greatest changes were noted for the summer season in Central Europe and Eastern Europe for the most recent 40-year period.
      Citation: Atmosphere
      PubDate: 2021-05-08
      DOI: 10.3390/atmos12050612
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 613: Reexamining the Impact of Industrial
           Structure on Haze Pollution Based on the Yangtze River Delta

    • Authors: Lu Wang, Shumin Jiang, Hua Xu
      First page: 613
      Abstract: In this study, the static and dynamic spatial Durbin model between industrial structure and haze pollution in Yangtze River Delta is constructed. Later, the spatial spillover effect and time lag effect of haze pollution in Yangtze River Delta are analyzed. The impact of rationalization and upgrading of industrial structure on haze pollution and its spatial spillover effect are discussed. The results show that: (i) PM2.5 has a significant positive spatial spillover effect and time lag effect; (ii) in the short run, the rationalization and upgrading of industrial structure has no inhibitory effect on haze pollution, while the rationalization and upgrading of industrial structure of surrounding cities has an inhibitory effect on local haze pollution; (iii) in the long run, the rationalization and upgrading of industrial structure of surrounding cities have an inhibitory effect on local haze pollution; (iv) economic growth, FDI, the number of Industrial Enterprises above Designated Size, and population density also have spatial spillover effects on haze pollution. Therefore, considering the spatial spillover effect of haze pollution from the perspective of urban agglomeration and long-term, strengthening the joint prevention and control and comprehensive treatment among cities, further promoting the rationalization and upgrading of industrial structure is conducive to reducing haze pollution.
      Citation: Atmosphere
      PubDate: 2021-05-09
      DOI: 10.3390/atmos12050613
      Issue No: Vol. 12, No. 5 (2021)
       
  • Atmosphere, Vol. 12, Pages 513: Immediate and Delayed Meteorological
           Effects on COVID-19 Time-Varying Infectiousness in Tropical Cities

    • Authors: Xerxes Seposo, Chris Fook Sheng Ng, Lina Madaniyazi
      First page: 513
      Abstract: The novel coronavirus, which was first reported in Wuhan, China in December 2019, has been spreading globally at an unprecedented rate, leading to the virus being declared a global pandemic by the WHO on 12 March 2020. The clinical disease, COVID-19, associated with the pandemic is caused by the pathogen severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Aside from the inherent transmission dynamics, environmental factors were found to be associated with COVID-19. However, most of the evidence documenting the association was from temperate locations. In this study, we examined the association between meteorological factors and the time-varying infectiousness of COVID-19 in the Philippines. We obtained the daily time series from 3 April 2020 to 2 September 2020 of COVID-19 confirmed cases from three major cities in the Philippines, namely Manila, Quezon, and Cebu. Same period city-specific daily average temperature (degrees Celsius; °C), dew point (degrees Celsius; °C), relative humidity (percent; %), air pressure (kilopascal; kPa), windspeed (meters per second; m/s) and visibility (kilometer; km) data were obtained from the National Oceanic and Atmospheric Administration—National Climatic Data Center. City-specific COVID-19-related detection and intervention measures such as reverse transcriptase polymerase chain reaction (RT-PCR) testing and community quarantine measures were extracted from online public resources. We estimated the time-varying reproduction number (Rt) using the serial interval information sourced from the literature. The estimated Rt was used as an outcome variable for model fitting via a generalized additive model, while adjusting for relevant covariates. Results indicated that a same-day and the prior week’s air pressure was positively associated with an increase in Rt by 2.59 (95% CI: 1.25 to 3.94) and 2.26 (95% CI: 1.02 to 3.50), respectively. Same-day RT-PCR was associated with an increase in Rt, while the imposition of community quarantine measures resulted in a decrease in Rt. Our findings suggest that air pressure plays a role in the infectiousness of COVID-19. The determination of the association of air pressure on infectiousness, aside from the testing frequency and community quarantine measures, may aide the current health systems in controlling the COVID-19 infectiousness by integrating such information into an early warning platform.
      Citation: Atmosphere
      PubDate: 2021-04-18
      DOI: 10.3390/atmos12040513
      Issue No: Vol. 12, No. 4 (2021)
       
  • Atmosphere, Vol. 12, Pages 515: Erratum: Hussein et al. Indoor Particle
           Concentrations, Size Distributions, and Exposures in Middle Eastern
           Microenvironments. Atmosphere 2020, 11, 41

    • Authors: Tareq Hussein, Ali Alameer, Omar Jaghbeir, Kolthoum Albeitshaweesh, Mazen Malkawi, Brandon E. Boor, Antti Joonas Koivisto, Jakob Löndahl, Osama Alrifai, Afnan Al-Hunaiti
      First page: 515
      Abstract: The authors would like to correct the published article [...]
      Citation: Atmosphere
      PubDate: 2021-04-19
      DOI: 10.3390/atmos12040515
      Issue No: Vol. 12, No. 4 (2021)
       
  • Atmosphere, Vol. 12, Pages 516: Associations between Exposure to
           Industrial Air Pollution and Prevalence of Asthma and Atopic Diseases in
           Haifa Bay Area

    • Authors: Raanan Raz, Yuval, Ruth Lev Bar-Or, Jeremy D. Kark, Ronit Sinnreich, David M. Broday, Ruthie Harari-Kremer, Lea Bentur, Alex Gileles-Hillel, Lital Keinan-Boker, Andrey Lyubarsky, Dorit Tsur, Arnon Afek, Noam Levin, Estela Derazne, Gilad Twig
      First page: 516
      Abstract: Haifa Bay Area (HBA) contains Israel’s principal industrial area, and there are substantial public concerns about health effects from its emissions. We aimed to examine associations between exposure to air pollution from HBA industrial area with prevalent asthma and other atopic diseases at age 17. This is a cross-sectional study. The study population included all adolescents born in Israel and whose medical status was evaluated for mandatory military recruitment by the Israeli medical corps during 1967–2017. We analyzed prevalent asthma, allergic rhinitis, atopic dermatitis, and rhinoconjunctivitis. We estimated exposure to industrial air pollution by a kriging interpolation of historical SO2 observations and adjusted the associations to the year of birth, SES, school orientation, and traffic pollution. The study population included n = 2,523,745 adolescents, among which 5.9% had prevalent asthma and 4.6% had allergic rhinitis. Residency in HBA was associated with a higher adjusted risk of asthma, compared with non-HBA residency. Still, this association was limited to the three lowest exposure categories, while the highest exposure group had the lowest adjusted risk. Sensitivity analyses and other atopic diseases presented similar results. These results do not provide support for causal relationships between HBA industry-related emissions and prevalent atopic diseases.
      Citation: Atmosphere
      PubDate: 2021-04-19
      DOI: 10.3390/atmos12040516
      Issue No: Vol. 12, No. 4 (2021)
       
  • Atmosphere, Vol. 12, Pages 517: Climatic Effects of Spring Mesoscale
           Oceanic Eddies in the North Pacific: A Regional Modeling Study

    • Authors: Zhiying Cai, Haiming Xu, Jing Ma, Jiechun Deng
      First page: 517
      Abstract: A high-resolution atmospheric model of the Weather Research and Forecast (WRF) is used to investigate the climatic effects of mesoscale oceanic eddies (OEs) in the North Pacific (NPac) in spring and the respective effects of OEs in the northern NPac associated with the Kuroshio Extension (KE) and of OEs in the southern NPac related to the subtropical countercurrent. Results show that mesoscale OEs in the NPac can strengthen the upper-level ridge (trough) in the central (eastern) subtropical NPac, together with markedly weakened (strengthened) westerly winds to its south. The mesoscale OEs in the whole NPac act to weaken the upper-level storm track and strengthen lower-level storm activities in the NPac. However, atmospheric responses to the northern and southern NPac OEs are more prominent. The northern NPac OEs can induce tropospheric barotropic responses with a tripole geopotential height (GPH) anomaly pattern to the north of 30° N, while the OEs in both the northern and southern NPac can enhance the upper-level ridge (trough) in the central (eastern) subtropical NPac. Additionally, the northern NPac OEs can shrink the lower-level subtropical high and weaken the easterly trade winds at the low latitudes, while the southern NPac OEs result in a southward shift of the lower-level subtropical high and an eastward shift of the upper-level westerly jet stream. The southern and northern NPac OEs have similar effects on the storm track, leading to an enhanced lower-level storm track over the KE via moistening the atmospheric boundary layer; and they can also exert significant remote influences on lower- and upper-level storm activities over the Northeast Pacific off the west coast of North America. When the intensities of OEs are doubled in the model, the spatial distribution of atmospheric responses is robust, with a larger and more significant magnitude. Additionally, although OEs are part of the mesoscale oceanic processes, the springtime OEs play an opposite role in mesoscale sea-surface temperature anomalies. These findings point to the potential of improving the forecasts of extratropical springtime storm systems and the projections of their responses to future climate change, by improving the representation of ocean eddy-atmosphere interaction in forecast and climate models.
      Citation: Atmosphere
      PubDate: 2021-04-19
      DOI: 10.3390/atmos12040517
      Issue No: Vol. 12, No. 4 (2021)
       
  • Atmosphere, Vol. 12, Pages 518: Impact of SARS-CoV-2 on Ambient Air
           Quality in Northwest China (NWC)

    • Authors: Shah Zaib, Jianjiang Lu, Muhammad Zeeshaan Shahid, Sunny Ahmar, Imran Shahid
      First page: 518
      Abstract: SARS-CoV-2 was discovered in Wuhan (Hubei) in late 2019 and covered the globe by March 2020. To prevent the spread of the SARS-CoV-2 outbreak, China imposed a countrywide lockdown that significantly improved the air quality. To investigate the collective effect of SARS-CoV-2 on air quality, we analyzed the ambient air quality in five provinces of northwest China (NWC): Shaanxi (SN), Xinjiang (XJ), Gansu (GS), Ningxia (NX) and Qinghai (QH), from January 2019 to December 2020. For this purpose, fine particulate matter (PM2.5), coarse particulate matter (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), and ozone (O3) were obtained from the China National Environmental Monitoring Center (CNEMC). In 2020, PM2.5, PM10, SO2, NO2, CO, and O3 improved by 2.72%, 5.31%, 7.93%, 8.40%, 8.47%, and 2.15%, respectively, as compared with 2019. The PM2.5 failed to comply in SN and XJ; PM10 failed to comply in SN, XJ, and NX with CAAQS Grade II standards (35 µg/m3, 70 µg/m3, annual mean). In a seasonal variation, all the pollutants experienced significant spatial and temporal distribution, e.g., highest in winter and lowest in summer, except O3. Moreover, the average air quality index (AQI) improved by 4.70%, with the highest improvement in SN followed by QH, GS, XJ, and NX. AQI improved in all seasons; significant improvement occurred in winter (December to February) and spring (March to May) when lockdowns, industrial closure etc. were at their peak. The proportion of air quality Class I improved by 32.14%, and the number of days with PM2.5, SO2, and NO2 as primary pollutants decreased while they increased for PM10, CO, and O3 in 2020. This study indicates a significant association between air quality improvement and the prevalence of SARS-CoV-2 in 2020.
      Citation: Atmosphere
      PubDate: 2021-04-19
      DOI: 10.3390/atmos12040518
      Issue No: Vol. 12, No. 4 (2021)
       
  • Atmosphere, Vol. 12, Pages 519: Measurements of NOx and Development of
           Land Use Regression Models in an East-African City

    • Authors: Asmamaw Abera, Ebba Malmqvist, Yumjirmaa Mandakh, Erin Flanagan, Michael Jerrett, Geremew Sahilu Gebrie, Abebe Genetu Bayih, Abraham Aseffa, Christina Isaxon, Kristoffer Mattisson
      First page: 519
      Abstract: Air pollution causes premature mortality and morbidity globally, but these adverse health effects occur over proportionately in low- and middle-income countries. Lack of both air pollution data and knowledge of its spatial distribution in African countries have been suggested to lead to an underestimation of health effects from air pollution. This study aims to measure nitrogen oxides (NOx), as well as nitrogen dioxide (NO2), to develop Land Use Regression (LUR) models in the city of Adama, Ethiopia. NOx and NO2 was measured at over 40 sites during six days in both the wet and dry seasons. Throughout the city, measured mean levels of NOx and NO2 were 29.0 µg/m3 and 13.1 µg/m3, respectively. The developed LUR models explained 68% of the NOx variances and 75% of the NO2. Both models included similar geographical predictor variables (related to roads, industries, and transportation administration areas) as those included in prior LUR models. The models were validated by using leave-one-out cross-validation and tested for spatial autocorrelation and multicollinearity. The performance of the models was good, and they are feasible to use to predict variance in annual average NOx and NO2 concentrations. The models developed will be used in future epidemiological and health impact assessment studies. Such studies may potentially support mitigation action and improve public health.
      Citation: Atmosphere
      PubDate: 2021-04-19
      DOI: 10.3390/atmos12040519
      Issue No: Vol. 12, No. 4 (2021)
       
  • Atmosphere, Vol. 12, Pages 520: Snow Processes and Climate Sensitivity in
           an Arid Mountain Region, Northern Chile

    • Authors: Francisco Jara, Miguel Lagos-Zúñiga, Rodrigo Fuster, Cristian Mattar, James McPhee
      First page: 520
      Abstract: Seasonal snow and glaciers in arid mountain regions are essential in sustaining human populations, economic activity, and ecosystems, especially in their role as reservoirs. However, they are threatened by global atmospheric changes, in particular by variations in air temperature and their effects on precipitation phase, snow dynamics and mass balance. In arid environments, small variations in snow mass and energy balance can produce large changes in the amount of available water. This paper provides insights into the impact of global warming on the mass balance of the seasonal snowpack in the mountainous Copiapó river basin in northern Chile. A dataset from an experimental station was combined with reanalysis data to run a physically based snow model at site and catchment scales. The basin received an average annual precipitation of approximately 130 mm from 2001 to 2016, with sublimation losses higher than 70% of the snowpack. Blowing snow sublimation presented an orographic gradient resultant from the decreasing air temperature and windy environment in higher elevations. Under warmer climates, the snowpack will remain insensitive in high elevations (>4000 m a.s.l.), but liquid precipitation will increase at lower heights.
      Citation: Atmosphere
      PubDate: 2021-04-20
      DOI: 10.3390/atmos12040520
      Issue No: Vol. 12, No. 4 (2021)
       
  • Atmosphere, Vol. 12, Pages 521: Study of Urban Heat Islands Using
           Different Urban Canopy Models and Identification Methods

    • Authors: Rui Silva, Ana Cristina Carvalho, David Carvalho, Alfredo Rocha
      First page: 521
      Abstract: This work aims to compare the performance of the single‑(SLUCM) and multilayer (BEP-Building effect parameterization) urban canopy models (UCMs) coupled with the Weather Research and Forecasting model (WRF), along with the application of two urban heat island (UHI) identification methods. The identification methods are: (1) the “classic method”, based on the temperature difference between urban and rural areas; (2) the “local method” based on the temperature difference at each urban location when the model land use is considered urban, and when it is replaced by the dominant rural land use category of the urban surroundings. The study is performed as a case study for the city of Lisbon, Portugal, during the record-breaking August 2003 heatwave event. Two main differences were found in the UHI intensity (UHII) and spatial distribution between the identification methods: a reduction by half in the UHII during nighttime when using the local method; and a dipole signal in the daytime and nighttime UHI spatial pattern when using the classic method, associated with the sheltering effect provided by the high topography in the northern part of the city, that reduces the advective cooling in the lower areas under prevalent northern wind conditions. These results highlight the importance of using the local method in UHI modeling studies to fully isolate urban canopy and regional geographic contributions to the UHII and distribution. Considerable improvements were obtained in the near‑surface temperature representation by coupling WRF with the UCMs but better with SLUCM. The nighttime UHII over the most densely urbanized areas is lower in BEP, which can be linked to its larger nocturnal turbulent kinetic energy (TKE) near the surface and negative sensible heat (SH) fluxes. The latter may be associated with the lower surface skin temperature found in BEP, possibly owing to larger turbulent SH fluxes near the surface. Due to its higher urban TKE, BEP significantly overestimates the planetary boundary layer height compared with SLUCM and observations from soundings. The comparison with a previous study for the city of Lisbon shows that BEP model simulation results heavily rely on the number and distribution of vertical levels within the urban canopy.
      Citation: Atmosphere
      PubDate: 2021-04-20
      DOI: 10.3390/atmos12040521
      Issue No: Vol. 12, No. 4 (2021)
       
  • Atmosphere, Vol. 12, Pages 522: A Machine Learning Based Ensemble
           Forecasting Optimization Algorithm for Preseason Prediction of Atlantic
           Hurricane Activity

    • Authors: Xia Sun, Lian Xie, Shahil Umeshkumar Shah, Xipeng Shen
      First page: 522
      Abstract: In this study, nine different statistical models are constructed using different combinations of predictors, including models with and without projected predictors. Multiple machine learning (ML) techniques are employed to optimize the ensemble predictions by selecting the top performing ensemble members and determining the weights for each ensemble member. The ML-Optimized Ensemble (ML-OE) forecasts are evaluated against the Simple-Averaging Ensemble (SAE) forecasts. The results show that for the response variables that are predicted with significant skill by individual ensemble members and SAE, such as Atlantic tropical cyclone counts, the performance of SAE is comparable to the best ML-OE results. However, for response variables that are poorly modeled by individual ensemble members, such as Atlantic and Gulf of Mexico major hurricane counts, ML-OE predictions often show higher skill score than individual model forecasts and the SAE predictions. However, neither SAE nor ML-OE was able to improve the forecasts of the response variables when all models show consistent bias. The results also show that increasing the number of ensemble members does not necessarily lead to better ensemble forecasts. The best ensemble forecasts are from the optimally combined subset of models.
      Citation: Atmosphere
      PubDate: 2021-04-20
      DOI: 10.3390/atmos12040522
      Issue No: Vol. 12, No. 4 (2021)
       
  • Atmosphere, Vol. 12, Pages 523: Influence of Meteorological Conditions and
           Aerosol Properties on the COVID-19 Contamination of the Population in
           Coastal and Continental Areas in France: Study of Offshore and Onshore
           Winds

    • Authors: Jacques Piazzola, William Bruch, Christelle Desnues, Philippe Parent, Christophe Yohia, Elisa Canepa
      First page: 523
      Abstract: Human behaviors probably represent the most important causes of the SARS-Cov-2 virus propagation. However, the role of virus transport by aerosols—and therefore the influence of atmospheric conditions (temperature, humidity, type and concentration of aerosols)—on the spread of the epidemic remains an open and still debated question. This work aims to study whether or not the meteorological conditions related to the different aerosol properties in continental and coastal urbanized areas might influence the atmospheric transport of the SARS-Cov-2 virus. Our analysis focuses on the lockdown period to reduce the differences in the social behavior and highlight those of the weather conditions. As an example, we investigated the contamination cases during March 2020 in two specific French areas located in both continental and coastal areas with regard to the meteorological conditions and the corresponding aerosol properties, the optical depth (AOD) and the Angstrom exponent provided by the AERONET network. The results show that the analysis of aerosol ground-based data can be of interest to assess a virus survey. We found that moderate to strong onshore winds occurring in coastal regions and inducing humid environment and large sea-spray production episodes coincides with smaller COVID-19 contamination rates. We assume that the coagulation of SARS-Cov-2 viral particles with hygroscopic salty sea-spray aerosols might tend to inhibit its viral infectivity via possible reaction with NaCl, especially in high relative humidity environments typical of maritime sites.
      Citation: Atmosphere
      PubDate: 2021-04-20
      DOI: 10.3390/atmos12040523
      Issue No: Vol. 12, No. 4 (2021)
       
  • Atmosphere, Vol. 12, Pages 524: Proposal to Refine Solar Radiation of
           Typical Meteorological Year Database and Evaluation on the Influence of
           Air-Conditioning Load

    • Authors: Jihui Yuan, Kazuo Emura, Craig Farnham
      First page: 524
      Abstract: The Typical meteorological year (TMY) database is often used to calculate air-conditioning loads, and it directly affects the building energy savings design. Among four kinds of TMY databases in China—including Chinese Typical Year Weather (CTYW), International Weather for Energy Calculations (IWEC), Solar Wind Energy Resource Assessment (SWERA) and Chinese Standard Weather Data (CSWD)—only CSWD is measures solar radiation, and it is most used in China. However, the solar radiation of CSWD is a measured daily value, and its hourly value is separated by models. It is found that the cloud ratio (diffuse solar radiation divided by global solar radiation) of CSWD is not realistic in months of May, June and July while compared to the other sets of TMY databases. In order to obtain a more accurate cloud ratio of CSWD for air-conditioning load calculation, this study aims to propose a method of refining the cloud ratio of CSWD in Shanghai, China, using observed solar radiation and the Perez model which is a separation model of high accuracy. In addition, the impact of cloud ratio on air-conditioning load has also been discussed in this paper. It is shown that the cloud ratio can yield a significant impact on the air conditioning load.
      Citation: Atmosphere
      PubDate: 2021-04-20
      DOI: 10.3390/atmos12040524
      Issue No: Vol. 12, No. 4 (2021)
       
 
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