Subjects -> METEOROLOGY (Total: 106 journals)
 Showing 1 - 36 of 36 Journals sorted alphabetically Acta Meteorologica Sinica       (Followers: 4) Advances in Atmospheric Sciences       (Followers: 45) Advances in Climate Change Research       (Followers: 49) Advances in Meteorology       (Followers: 27) Advances in Statistical Climatology, Meteorology and Oceanography       (Followers: 11) Aeolian Research       (Followers: 7) Agricultural and Forest Meteorology       (Followers: 20) American Journal of Climate Change       (Followers: 36) Atmósfera       (Followers: 2) Atmosphere       (Followers: 33) Atmosphere-Ocean       (Followers: 16) Atmospheric and Oceanic Science Letters       (Followers: 13) Atmospheric Chemistry and Physics (ACP)       (Followers: 43) Atmospheric Chemistry and Physics Discussions (ACPD)       (Followers: 15) Atmospheric Environment       (Followers: 72) Atmospheric Environment : X       (Followers: 3) Atmospheric Research       (Followers: 73) Atmospheric Science Letters       (Followers: 40) Boundary-Layer Meteorology       (Followers: 32) Bulletin of Atmospheric Science and Technology       (Followers: 5) Bulletin of the American Meteorological Society       (Followers: 63) Carbon Balance and Management       (Followers: 6) Ciencia, Ambiente y Clima       (Followers: 1) Climate       (Followers: 8) Climate and Energy       (Followers: 6) Climate Change Economics       (Followers: 44) Climate Change Responses       (Followers: 23) Climate Dynamics       (Followers: 45) Climate Law       (Followers: 6) Climate of the Past (CP)       (Followers: 6) Climate of the Past Discussions (CPD)       (Followers: 1) Climate Policy       (Followers: 51) Climate Research       (Followers: 9) Climate Resilience and Sustainability       (Followers: 21) Climate Risk Management       (Followers: 10) Climate Services       (Followers: 4) Climatic Change       (Followers: 69) Current Climate Change Reports       (Followers: 17) Dynamics and Statistics of the Climate System       (Followers: 6) Dynamics of Atmospheres and Oceans       (Followers: 19) Earth Perspectives - Transdisciplinarity Enabled       (Followers: 1) Economics of Disasters and Climate Change       (Followers: 13) Energy & Environment       (Followers: 24) Environmental and Climate Technologies       (Followers: 3) Environmental Dynamics and Global Climate Change       (Followers: 21) Frontiers in Climate       (Followers: 4) GeoHazards       (Followers: 2) Global Meteorology       (Followers: 20) International Journal of Atmospheric Sciences       (Followers: 25) International Journal of Biometeorology       (Followers: 3) International Journal of Climate Change Strategies and Management       (Followers: 29) International Journal of Climatology       (Followers: 28) International Journal of Environment and Climate Change       (Followers: 20) International Journal of Image and Data Fusion       (Followers: 3) Journal of Agricultural Meteorology Journal of Applied Meteorology and Climatology       (Followers: 42) Journal of Atmospheric and Oceanic Technology       (Followers: 33) Journal of Atmospheric and Solar-Terrestrial Physics       (Followers: 133) Journal of Atmospheric Chemistry       (Followers: 23) Journal of Climate       (Followers: 56) Journal of Climate Change and Health       (Followers: 4) Journal of Climatology       (Followers: 4) Journal of Hydrology and Meteorology       (Followers: 39) Journal of Hydrometeorology       (Followers: 10) Journal of Integrative Environmental Sciences       (Followers: 4) Journal of Meteorological Research       (Followers: 2) Journal of Meteorology and Climate Science       (Followers: 21) Journal of Space Weather and Space Climate       (Followers: 30) Journal of the Atmospheric Sciences       (Followers: 83) Journal of the Meteorological Society of Japan       (Followers: 7) Journal of Weather Modification       (Followers: 4) Mediterranean Marine Science       (Followers: 2) Meteorologica       (Followers: 2) Meteorological Applications       (Followers: 4) Meteorological Monographs       (Followers: 1) Meteorologische Zeitschrift       (Followers: 4) Meteorology and Atmospheric Physics       (Followers: 29) Mètode Science Studies Journal : Annual Review Michigan Journal of Sustainability       (Followers: 1) Modeling Earth Systems and Environment       (Followers: 1) Monthly Notices of the Royal Astronomical Society       (Followers: 13) Monthly Weather Review       (Followers: 30) Nature Climate Change       (Followers: 145) Nature Reports Climate Change       (Followers: 40) Nīvār       (Followers: 1) npj Climate and Atmospheric Science       (Followers: 6) Open Atmospheric Science Journal       (Followers: 6) Open Journal of Modern Hydrology       (Followers: 5) Revista Iberoamericana de Bioeconomía y Cambio Climático       (Followers: 1) Russian Meteorology and Hydrology       (Followers: 4) Space Weather       (Followers: 27) Studia Geophysica et Geodaetica       (Followers: 1) Tellus A       (Followers: 21) Tellus B       (Followers: 20) The Cryosphere (TC)       (Followers: 8) The Quarterly Journal of the Royal Meteorological Society       (Followers: 32) Theoretical and Applied Climatology       (Followers: 14) Tropical Cyclone Research and Review       (Followers: 1) Urban Climate       (Followers: 5) Weather       (Followers: 20) Weather and Climate Dynamics       (Followers: 1) Weather and Climate Extremes       (Followers: 18) Weather and Forecasting       (Followers: 43) Weatherwise       (Followers: 18) 气候与环境研究       (Followers: 2)
Similar Journals
 Meteorology and Atmospheric PhysicsJournal Prestige (SJR): 0.543 Citation Impact (citeScore): 1Number of Followers: 29      Hybrid journal (It can contain Open Access articles) ISSN (Print) 1436-5065 - ISSN (Online) 0177-7971 Published by Springer-Verlag  [2469 journals]
• Influence of soil moisture on mean daily maximum and minimum temperatures
over India

Abstract: Abstract Soil moisture–temperature coupling plays a significant role in the persistence and amplification of extreme events such as droughts and heatwaves. Hence, a better understanding of soil moisture–temperature coupling can enhance the predictability associated with these extreme events. In this study, we investigate soil moisture coupling on mean daily maximum ( $$T_\mathrm{{max}}$$ ) and minimum ( $$T_\mathrm{{min}}$$ ) temperature over the Indian region. The results show that soil moisture exhibits negative feedback on $$T_\mathrm{{max}}$$ and $$T_\mathrm{{min}}$$ over central and north India leading to substantial negative feedback on Daily Temperature Range (DTR). Positive feedback is observed over a few regions of north-west India. In general, stronger negative feedback is observed for $$T_\mathrm{{max}}$$ than $$T_\mathrm{{min}}$$ . The negative feedback induced variability accounts for 5–30% of the total variability of temperature. A strong dependence of evapotranspiration on $$T_\mathrm{{max}}$$ , $$T_\mathrm{{min}}$$ and DTR is observed for central and north Indian regions.
PubDate: 2022-04-25

• Projected changes in wind energy potential using CORDEX ensemble
simulation over West Africa

Abstract: Abstract Expected changes in climate are likely to affect the energy production from wind. This study investigates projected changes in wind energy production under a changing climate over West Africa using the ensemble of regional climate models. Wind power output (Pout) is estimated using the ensemble of seven regional climate models participating in the Coordinated Regional Climate Downscaling Experiment (CORDEX) project. The ensemble mean of near-surface wind speed from the model simulations was compared with re-analysis datasets from ERA-5 between 1980 and 2005. While some biases were observed in the model performance over West Africa, the model ensemble provided a good representation of wind speed characteristics over the study region. The result shows that there is a potential reduction in energy produced up to 12% as a negative change is simulated in Pout in the near future (2021–2050) when compared to the reference period of 1971–2000. There is however a possible increment (about 24–30%) in power production in the far future (2071–2100) over most region of West Africa. In terms of variations of seasonal changes in Pout, there is more decline (− 8%) observed during the winter months of December to February (DJF) as compared to the summer season of June to August (JJA). The Sahel zone averaged wind power production up to 1.4 MW, while the Guinea and Savannah zones simulated lesser wind power output. In the Guinea region, an increasing inter-annual variability trend of up to 80% is estimated in Nigeria, Ghana, etc. towards the end of the century (2071–2100) as compared to historical years of 1971–2000. Our results provide a guide to government agencies and policymakers towards massive investment in harnessing wind energy in the future.
PubDate: 2022-04-25

• Identifying temporal trend patterns of temperature means and extremes over
the Central Highlands, Vietnam

Abstract: Abstract Conducting an in-depth quantification of warming conditions in a given region is crucially conducive to devising more informed, credible, and effective climate actions. The traditional approach commonly is to apply a single monotonic trend test for specified beginning and ending times within a predetermined period, which is sensitive to the analyzed period. Thus, the present study aimed to apply multiple non-parametric statistical trend tests to the observed daily mean, maximum, and minimum temperature records at 12 sites located proportionally to the whole extent of the Central Highlands, Vietnam. This approach was implemented by performing Sen’s slope estimator and block bootstrapping Mann–Kendall tests repeatedly with various beginning and ending years for all possible periods of at least 10 years in length during 1980–2019. This study also delved into non-monotonic trend components in temperature means and extremes by employing an innovative trend analysis (ITA) methodology. The outcomes indicated significant warming trends in the annual mean, maximum, and minimum temperatures, with the estimated trend slopes varying mainly from 0.30–0.43, 0.09–0.25, and 0.41–0.52 °C/decade, respectively. Most extreme temperature indices (i.e., Max Tmin, Min Tmin, warm spell duration indicator, warm days/nights) were characterized mainly by positive trends. The results also pointed out higher warming levels in the annual mean and minimum temperatures than the annual maximum one, and likewise, most extreme temperature indices deriving from daily minimum temperature exhibited faster rates than those from maximum one. These findings highlight the superiority of applying the multiple trend tests and ITA method to clarify temporal trend patterns.
PubDate: 2022-04-18

• The role of the Red Sea in moisture feeding of flood events of Iran with
emphasis on atmospheric river concept

Abstract: Abstract Southwest Asia is located in the descending branch of the Hadley cell with a dry climate. As one of the countries located in this area, Iran receives 220 mm annual rainfall, equal to one-third of the global average. However, various severe and short-term torrential rainfalls, which lead to a flood event in some areas, could be observed in the precipitation season each year. Therefore, mechanisms of transferring huge moist air from the nearby water basin to the country at the time of the flood and its interaction with the complicated topography of Iran is a fundamental question that so far was less investigated. In the present study, the moisture routing is examined for two flooding events in the south and west of Iran using the Atmospheric Rivers (AR) algorithm. Furthermore, the divergence of the moisture flux was applied to determine the source and sink of humidity. The results showed that an AR event which has received moisture from the Red and Arabian Seas has accompanied by flood event in the west of Iran. But the main humidity source of the second one has been the Persian Gulf which did not have AR characteristics. The low-level flow in the two cases was the main factor to transport humidity from the nearby water basin to the inland of Iran. While the convergence of moisture due to upsloping motion over the Zagros Mountain was the main cause of heavy rainfall and flood event. The moisture path of the two cases originated from the divergence zone associated with the cold front of the low pressure then intensified and fed on the way by other water basins.
PubDate: 2022-04-18

• Drought occurrences and impacts on the upper Grande river basin, Brazil

Abstract: Abstract Natural hazards, such as droughts and floods, are the main challenge for research related to water resource management worldwide. Understanding how the climate affects the occurrence and propagation of droughts can assist in water management. This study aimed to investigate the occurrence and characteristics of meteorological and hydrological droughts in the upper Grande river basin (UGRB). For this purpose, the Standardized Precipitation Index (SPI) and the Streamflow Drought Index (SDI) were calculated on an annual time scale, considering the regional water year, i.e., a period beginning in October of a year and ending in September of the following year. Besides, it was aimed to verify the impact of macroscale climatic phenomena on seasonal precipitation anomalies using composite analysis. The SPI was calculated from the monthly precipitation series from October 1976 to September 2017. To calculate the SDI, daily naturalized streamflows were obtained from October 1990 to September 2017. The most severe droughts were observed in 2000/01, 2013/14, and 2014/15 water years. Although there was an agreement between the meteorological and hydrological droughts, the SDI indicated that the impacts on the streamflow were longer. The propagation from meteorological to hydrological drought was greatest with up to a 6-month lag in SPI, after that the influence of SPI on SDI was less. Composite analysis revealed an antiphase relationship between Pacific and Atlantic climatic indices and seasonal precipitation anomalies, indicating interannual-to-multidecadal variability.
PubDate: 2022-04-12

• Assessing tropical cyclones characteristics over the Arabian Sea and Bay
of Bengal in the recent decades

Abstract: Abstract The tropical cyclones (TCs) are most likely to increase over the North Indian Ocean (NIO) due to rapid heating in a warming climate. However, past studies have made contrasting statements while analyzing different study periods. This study examines the variability of TC’s characteristics such as severity, frequency, and longevity over the Arabian Sea (ARB) and the Bay of Bengal (BoB) during the satellite era (1990–2017). The cumulative frequency of depression, deep depression events and intense storms (combining very severe cyclonic storms, extremely severe cyclonic storms, and super cyclonic storms) have been found to increase (decrease) in the ARB (BoB). However, the cumulative frequency of all TCs (wind speed > 61 kmph) in the two basins has shown an insignificant change during the study period. The number of annual cyclonic days over both the basins has also witnessed a slight enhancement, suggesting an increase in the duration of TCs. Wind-driven energy metrics “power dissipation index (PDI)” and “accumulated cyclone energy (ACE)” are computed and compared against the mean sea level pressure-driven metric “accumulated cyclone intensity (ACI)” using the ‘Best-Tracks’ data from the India Meteorological Department (IMD), analyzing the climatology of cyclone’s destruction potential, energy, and intensity. The trends for three metrics have revealed a rise (fall) in the ARB (BoB), although not significant. Results indicate that the ARB basin has shown a higher capability of developing very intense TCs when compared to the BoB basin in recent years. Annually integrated values of the employed metrics have evidently affirmed the associated variations during the El Nino, La Nina, and Indian Ocean Dipole (IOD) phases. ACI values over both the basins were found to be increased in the La Nina years, whereas it decreased (increased) in the negative IOD years over the ARB (BoB).
PubDate: 2022-04-11

• Vertical structures of winter-season stratiform rainfall over central
Himalaya

Abstract: Abstract Characteristics of the winter-season vertical structures of stratiform rainfall over central Himalaya are investigated using a vertically pointing Micro Rain Radar (MRR) at GBPNIHE, Kosi-Katarmal, Almora (29.59 $$^\circ$$ N, 79.65 $$^\circ$$ E), India. Rainfall micro-structures, such as reflectivity (Z), rain rate (R), liquid water content (LWC) and average fall speed of the drops ( $$v_m$$ ) upto 6000 m above ground are monitored during 01 November, 2020 to 28 February, 2021. The MRR observations are used to (1) identify bright band signatures, and develop linear parameterizations between maximum radar reflectivity and radar reflectivities of snow and rain layers, (2) quantify changes in the vertical profiles of Z, R, LWC and $$v_m$$ , (3) evaluate near surface rainfall drop size distribution and its linkages to drop diameter, and (4) investigate vertical profiles of Z–R relationships using Marshall–Palmer distribution, during stratiform rain. We find that 25.4% of all the observed rainfall events is associated with bright band signatures, where bright bands are observed at an average 2536.5 (± 422.1) m height above the ground associated with mean maximum reflectivity of 20.8 (± 2.37) dBZ. Almost linear relationships amongst maximum reflectivity and reflectivities of snow and rain layers during bright band signatures are observed. The near-surface raindrop size distributions of this study indicate mean drop concentrations during January and February months are 3.78 (± 0.09) m $$^3$$ mm $$^{-1}$$ , whereas the same during December is 3.45 (± 0.17) m $$^3$$ mm $$^{-1}$$ . Highest drop diameter of 4.94 mm is obtained during rain events of January and February, 2021, due to higher coalescence of drops. Coefficients a and b of the power–law relationships between Z–R varied between 246.0 and 367.5 and 1.61 and 2.45, respectively, within the reported range of stratiform rain in India.
PubDate: 2022-04-05

• Long-term temporal trend analysis of climatic parameters using polynomial
regression analysis over the Fasa Plain, southern Iran

Abstract: Abstract The climate conditions of Iran vary from extremely arid in south parts to very humid in the northern parts. In the past two decades, severe droughts and population growth as well as inappropriate management of water resources have intensified Iran's water shortage problems. In this study, we used the Polynomial Regression Analysis (PRA) to investigate the trend of climatic parameters, including minimum and maximum air temperature, total monthly rainfall, average monthly relative humidity, sunshine hours, and average monthly wind speed at Fasa Plain, southern Iran with semi-arid climate during 1967–2019. For each parameter, a significant trend in each month was determined by the model contained a linear effect (t), quadratic effect (t2), cubic effect (t3), and so on. Results indicated that the temporal trend of minimum and maximum temperature was significantly increasing (maximum values of 0.358 and 0.316 °C year−1 in March and April, respectively) during 1967–2014. While the trend of rainfall has fluctuated and almost significantly decreased (maximum decrement of − 3.367 mm year−1 in March). Sunshine hours had an increasing trend in recent decades (maximum of 3.220 h year−1 in December), wind speed had a quite negative trend (maximum reduction of − 0.194 m/s year−1 in January), and relative humidity had a more decreasing trend (maximum decline of − 1.284% year−1 in November) in the studied duration. Total changes in the studied meteorological parameters are indicative of more warmth and dryness of the region. Rainfall reduction in March and April is in agreement with warming and drying, during 1967–2014. Then, the validation of the obtained equations was assessed using meteorological data of the study area during 2015–2019. The forecasted results showed the acceptable values of coefficient of determination (R2) between forecasted and actual data. In general, the results of this study indicate a serious warning about warming and climate change in the studied region.
PubDate: 2022-03-27

• Probable maximum precipitation (PMP) and flood (PMF) risk charts in Hodna
basin, Algeria

Abstract: Abstract Flood magnitude, frequency and intensity are bound to increase in many parts of the world due to global warming and its consequent effect as climate change impacts. The main purpose of this paper is to apply the classical probable maximum precipitation and probable maximum flood methodologies leading to a new concept of risk level charts, which provide hydrograph time to peak probable maximum discharge after the beginning of precipitation, base time and peak discharge values. Dimensionless hydrograph methodology is employed for flood hydrograph analysis. The applications of probable maximum precipitation and probable maximum flood methodologies are presented for Algerian meteorology stations’ annual maximum daily precipitation amounts from 23 different locations at Hodna drainage basin in the north-eastern of Algeria. Classical probable maximum precipitation frequency factor is obtained for each meteorology station record, which are then converted to pointwise probable maximum flood amounts that are helpful to construct practically applicable flood charts. A new relationship is provided between probable maximum precipitation and the frequency factor for the study area. The efficiency factor is calculated for each station to understand whether there is a further possibility for extreme precipitation, and consequent flood occurrences.
PubDate: 2022-03-23

• Measurement of atmospheric conductivity on the Qinghai-Tibet Plateau in
China

Abstract: Abstract Two feasible methods (the current–voltage method and the voltage decay method) for measuring atmospheric conductivity were introduced in this paper, both variants within the Gerdien tube method. To explore the characteristics of atmospheric conductivity, we performed two balloon flight experiments on the Qinghai-Tibet Plateau on 27 August 2019 and 14 September 2020, and these two approaches were used. Detailed experiments and methods and a series of experimental results are presented in this paper. The current–voltage method was used during the first experiment, and we further demonstrated that atmospheric conductivity changed with changing altitude, primarily under the action of atmospheric gas and ionic composition. The balloon passed through the clouds by chance, and we found that clouds caused abnormal variation in atmospheric conductivity; the measured conductivity of the atmosphere changed suddenly by 7.5 × 10–13 − 1.5 × 10–12 Ω−1 m−1, which may have been caused by water vapor or charges in the clouds. For the second experiment, the voltage decay method was used to explore further characteristics of atmospheric conductivity at the same location on the plateau. Unfortunately, the balloon did not fly because of the device, and positive conductivity and negative conductivity were measured on the ground at an altitude of 3.2 km. The feasibility of the two methods was proven by the two experiments. At the end of the paper, we have discussed the experimental error and details of the two measuring methods, which can be used as a reference for researchers concerned with atmospheric electricity.
PubDate: 2022-03-22

• Evaluation of the suitability of NCEP/NCAR, ERA-Interim and, ERA5
reanalysis data sets for statistical downscaling in the Eastern Black Sea
Basin, Turkey

Abstract: Abstract Climate community frequently uses gridded reanalysis data sets in their climate change impact studies. However, these studies for a region yield more realistic results depending on the rigorous analysis of the reanalysis data sets for this region. This study aims to determine the most suitable reanalysis data set for the statistical downscaling method in the Eastern Black Sea Basin, one of Turkey's most important hydrological basins owing to the precipitation it receives throughout the year. For this purpose, the monthly mean temperature and total precipitation data measured from the 12 meteorological stations and 12 large-scale predictors of the NCEP/NCAR, ERA-Interim, and ERA5 reanalysis data sets were used. The multivariate adaptive regression splines (MARS) and conventional regression analysis with linear and exponential functions were used to create effective statistical downscaling models. For evaluating and comparing the performance of the downscaling models with three different reanalysis data set, four performance statistics (root means square error, scatter index, mean absolute error, and the Nash Sutcliffe coefficient of efficiency) were used. Besides, the relative importance of the input variables of the models was determined. The study revealed that the values obtained from the models of ERA5 were closer to the precipitation and temperature values measured from the meteorological stations. In addition, the model performances with three reanalysis data sets for the temperature variable were very close to each other. The study results have shown that the MARS method, which gives the highest performance values, can be used successfully as a statistical downscaling method in climate change impact studies.
PubDate: 2022-03-17

• Signature of teleconnection patterns in river discharge within the Niger
Basin

Abstract: Abstract Teleconnection patterns play critical roles in the climate of West Africa. However, their role in river dynamics within the Niger Basin has not been adequately investigated. In this study, the contribution and influence of four teleconnection patterns on river discharges at eight stations across the Niger basin were investigated using sensitivity analysis, mutual information and wavelet coherence. The objective of the study is to understand the influence of teleconnection patterns on the river discharge within the Niger Basin. Annual sensitivity of river discharges were found to be in the range 8–41%, 0.4–2.5%, 2.2–46.4%, and 26.0–62.8% for Dipole Mode Index (DMI), Southern Oscillation Index (SOI), Tropical North Atlantic (TNA), and Tropical South Atlantic (TSA) respectively. The nonlinear dependence, captured by mutual information measure, suggests that the interaction between SOI and river discharge within the Niger basin is nonlinear. Pronounced relationships between river discharge and teleconnection patterns were observed at the annual, sub-annual, and higher scale over various years using wavelet coherence analysis. The seasonal response of river discharge to teleconnection patterns across the region was observed to be heterogeneous.
PubDate: 2022-03-12

• On the importance of non-ideal sulphate processing of multi-component
aerosol haze over urban areas

Abstract: Abstract Urban aerosol-haze over fast-growing Asian mega-cities pose health and aviation-related problems requiring a combination of large-scale multidisciplinary field experiments as well as numerical modelling to address them holistically. Although a repository of rain and cloud microphysical data is available over the Asian sub-continent, data related to haze microphysics remain scanty. Heterogeneously processed sulphate increases the solubility of existing aerosol mixtures through non-ideal interactions over micron as well as sub-micron regimes. The methodology followed in this paper combines in-situ aircraft-based microphysical observations followed by heterogeneous cloud processing procedures. It is shown for the first time that the extent of processed sulphate accretion is comparable to the original aerosol sulphate contents to the extent that some hydrophobic black carbon particles are rendered hydrophilic after cloud processing. It is also shown that haze-mediated cloud droplets are acidic with a solution pH range of 0.5–4.0 and that solution non-ideal behaviour over the smallest haze droplets is around 29%. Modelled spectra match up with the observed spectra after two cycles of cloud processing only when the effects of a variable composition of a multi-modal spectrum growing in concentrated ionic solutions are accounted for. Importantly, the study shows that although 35.6% of the aerosols are activated, 78.6% of the smallest particles (Mode I—modal radius 0.03 μm) fall within a restricted Köhler growth regime. The results from this study are also likely to impact new research through better model parameterisations and linking haze processes into large-scale atmospheric models.
PubDate: 2022-03-10

• Estimation of the probable maximum precipitation (PMP) in the Cheliff
semi-arid region (Algeria)

Abstract: Abstract The design of hydraulic infrastructure requires careful evaluation of extreme precipitation events. This paper presents an estimation of extreme precipitation events based on the Probable Maximum Precipitation (PMP) concept. The PMP approach is useful in determining probable maximum flood (PMF), which is required for the design of large hydraulic structures. Therefore, in this study, 24-h PMP estimates were performed through 43 rainfall stations located in the Cheliff watershed in Algeria. This estimation was implemented based on moisture maximization and Hershfield statistical method. The 24-h PMP values vary between 109.2 and 741.6 mm for the first approach and between 151.5 and 369.4 mm for the second approach. Using the moisture maximization approach, the 24-h PMP values obtained are approximately double those based on the Hershfield statistical method, with return periods ranging from 1000 to 28 106 years for the majority of stations in the Cheliff basin.
PubDate: 2022-03-04

• A thermodynamic condition affecting the movement of a southwest China
vortex case

Abstract: Abstract From 30 June to 5 July 2016, a persistent rainstorm occurred in the Yangtze River basin, China, causing severe floods. This was a rainstorm event associated with a southwest China vortex (SWCV), and four movements of the SWCV were observed. In this paper, we analyze a thermodynamic condition affecting the movement of the SWCV, and the results show that: (1) Equivalent potential temperature could reflect well the thermodynamic variation of the SWCV’s movement; thermodynamic structures including distinctive wet–warm (dry–cold) advection in the front (rear) of the SWCV along the direction of motion were important factors for its movement and maintaining the overall cyclonic structure, while dry–cold advection promoted eastward movement of the SWCV. (2) In the four movements of the SWCV, the system existed not only at 700 hPa but also sometimes at 850 hPa. The reasons for this difference lay in the variation of the dry–cold advection in the rear of the SWCV. If the dry–cold advection was located at 700 hPa and above, the cyclonic circulation of the SWCV at 700 hPa was the most complete. The circulation of the 850-hPa SWCV became complete if the dry–cold advection flowed down to 850 hPa and below. Therefore, the synergy between the wet–warm (dry–cold) advection in the front (rear) of the SWCV not only facilitated the movement of the SWCV, but also the maintenance of a complete cyclonic circulation.
PubDate: 2022-03-04

• Meteorological trend analysis for Najd and Hejaz regions, Saudi Arabia

Abstract: Abstract Global warming and abrupt seasonal changes are the current challenging issues across the globe. This study investigated the trends in average temperature and precipitation on monthly basis for the designated stations of Najd and Hejaz regions of Saudi Arabia, namely Qassim, Riyadh, Tabuk, Medina, Mecca, Al-Baha, Hail and Jizan. Two non-parametric techniques are used for this purpose. In the first stage, the Mann–Kendall test is applied to determine the trends and in the later stage, the Sen’s slope test is utilized to determine the extent of the trends. The Mann–Kendall test with a 5% significance level was applied to the 30-year data of eight selected stations from 1985 to 2014. The analysis showed increasing trends only in mean monthly temperature at all eight stations throughout the year, whereas Tabuk and Riyad showed increasing trends, while Medina, Qassim and Hail exhibited decreasing trends in precipitation in four different months of the year. The trend in precipitation at Mecca, Al-Baha and Jizan was insignificant throughout the year. From the results of Sen’s Slope test, it was concluded that the trend pattern is associated with the intensity of trend values. It was also found that temperature is rising in three of the four seasons on an annual basis during the study period. From the results, longer summer and shorter winter are expected in the future due to rising temperature. It can also be inferred that the increasing temperature will increase the evaporation from the sea causing a humid environment which can result in a heavy downpour in the near future especially in coastal areas. The rising temperature and changing pattern of precipitation may increase uncertainty in developing strategies for water resources management.
PubDate: 2022-03-04

• Ocean–atmosphere dynamics and Rossby waves in fractal anisotropic
media

Abstract: Abstract We study some basic problems arising in ocean–atmosphere dynamics including the ocean surface waves and Rossby waves based on the concept of product-like fractal measure introduced recently by Li and Ostoja-Starzewski in their formulation of anisotropic media. We have derived the fractal fluid equations and we have analyzed several fundamental problems related to earth’s ocean and Rossby waves. This study demonstrates the mutual effects of eastward-propagating stationary barotropic Rossby waves and westward-propagating stationary barotropic Rossby waves in the atmosphere which are in agreement with some recent studies and satellite observations. Numerical estimates of fractal dimensions were also given.
PubDate: 2022-02-27
DOI: 10.1007/s00703-022-00867-9

• A WRF-FLEXPART simulation study of oil-fire plume dispersion- sensitivity
to turbulent diffusion schemes

Abstract: Abstract In this work, we simulate the dispersion of oil-fire aerosols from the accident at Abqaiq oil processing facility in Saudi Arabia during 14–16 September 2019 using the Lagrangian dispersion model FLEXPART-WRF (version 3.1) to investigate the sensitivity of local and nonlocal turbulence parameterization schemes on the dispersion dynamics. The Weather Research and Forecasting (WRF version 4.0) model is used to simulate the meteorological parameters over the 2-day release period at a resolution of 2 km. Two Planetary Boundary Layer (PBL) schemes (MYNN level 2.5 and YSU) are used to simulate the boundary layer structure during the fire episode. Comparison with available surface and upper-air observations indicate fairly similar results, showing good agreement between simulation and observations. The FLEXPART-WRF v3.1 model is run with two turbulence diffusion schemes, Hanna and Hanna-TKE Hybrid. Meteorological predictions of WRF-YSU are coupled with Hanna diffusion scheme (hereafter YSU-Hanna) and predictions of MYNN2.5 are coupled with Hanna-TKE Hybrid scheme (hereafter MYNN-TKE). Simulated plume dispersion patterns are compared with Moderate Resolution Imaging Spectroradiometer (MODIS)/Terra and LANDVIWER Earth Observing System imagery. Though, in general the simulated plumes compare well with the satellite observed plume, MYNN-TKE simulates a wider plume beyond 20 km and YSU-Hanna produces more accurate plume pattern and plume width. Both schemes could reproduce the downwind variation of concentration. While YSU-Hanna slightly overestimates the concentration at all distances, MYNN-TKE underestimates for an initial 5 km and then closely follows observation derived data. While both schemes produces nearly similar behaviour of vertical concentration variation in both daytime and nighttime conditions, YSU-Hanna overestimates the concentration profile in the lower level region by approximately 25% compared to MYNN-TKE. Overall, YSU-Hanna performs slightly better than MYNN-TKE in reproducing the observed plume behaviour.
PubDate: 2022-02-25
DOI: 10.1007/s00703-022-00866-w

• Does drought show a significant weakening trend from 1961 to 2017 in
northern China'

Abstract: Abstract Understanding the multi-dimensional drought variation and its driving mechanism is essentially important in climate change and risk assessment. Based on the monthly meteorological data at 321 stations from northern China, this study computed the Standardized Precipitation Evapotranspiration Index (SPEI), which was estimated using the potential evapotranspiration (PET) with the Penman–Monteith equation. Drought displayed the wetting trend in 1961–2017 at a rate of 0.05/10a, which generally occurred in winter and in most study areas. In contrast, the apparent drying trend occurred on the Loess Plateau. The piecewise linear regression method (LRM) identified that the turning point (TP) for trends occurred in 1990; the annual SPEI had been increasing pre-1990 and decreasing post-1990. This was especially the case in the Xinjiang Uygur Autonomous Region, Tibet, Gansu, and Inner Mongolia, consistent with patterns of seasonal drought at their respective TP apart from autumn. From 1961 to 2017, the drought-affected area decreased at a rate of − 1.69%/10a (p < 0.05). The area decreased before the TP and increased after the TP at different drought levels. The seasonal drought-affected area also showed decreasing trend, particularly in winter. The highest frequency and duration of drought occurred in the Loess Plateau and Xinjiang Uygur Autonomous Region, respectively, although it decreased post-1990. These findings suggest that long-term trends in drought were not significant in northern China during 1961–2017. Although the severity, frequency, and duration of drought decreased post-1990, the recent increasing drying trend and drought-affected area should not be dismissed.
PubDate: 2022-02-23
DOI: 10.1007/s00703-022-00860-2

• Classification of synoptic and local-scale wind patterns using k-means
clustering in a Tyrrhenian coastal area (Italy)

Abstract: Abstract In coastal regions, the complex interaction of synoptic-scale dynamics and breeze regimes influence the local atmospheric circulation, permitting to distinguish typical yet alternative patterns. In this paper, the k-means clustering algorithm is applied to the hourly time series of wind intensity and direction collected by in-situ weather stations at seven locations within 30 km from the western coastline of central Italy, in the proximity of Rome, over the period 2014–2020. The selection of both wind-integral quantities and ad hoc objective parameters allows for the identification of three characteristic clusters, two of which are closely related to the synoptic circulation and governed by persistent winds, blowing from either the northeast or the southeast direction throughout the day. In the latter case, synoptic and mesoscale contributions add up, giving rise to a complex circulation at the ground level. On the contrary, the third cluster is closely related to the sea breeze regime. The results allow the identification of some general information about the low-level circulation, showing that the synoptic circulation dominates in winter and, partly, in spring and autumn, when high ventilation and low recirculation conditions occur. Conversely, during summer the sea breeze regime is more frequent and stronger, generating intense air recirculation. Our analysis permits to discern rigorously and objectively the typical coastal meteorological patterns, only requiring anemological in-situ data.
PubDate: 2022-02-22
DOI: 10.1007/s00703-022-00871-z

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