 Subjects -> GEOGRAPHY (Total: 493 journals)
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- Ch3MS-RF: a random forest model for chemical characterization and improved
quantification of unidentified atmospheric organics detected by
chromatography–mass spectrometry techniques
Abstract: Ch3MS-RF: a random forest model for chemical characterization and improved quantification of unidentified atmospheric organics detected by chromatography–mass spectrometry techniques
Emily B. Franklin, Lindsay D. Yee, Bernard Aumont, Robert J. Weber, Paul Grigas, and Allen H. Goldstein
Atmos. Meas. Tech., 15, 3779–3803, https://doi.org/10.5194/amt-15-3779-2022, 2022
The composition of atmospheric aerosols are extremely complex, containing hundreds of thousands of estimated individual compounds. The majority of these compounds have never been catalogued in widely used databases, making them extremely difficult for atmospheric chemists to identify and analyze. In this work, we present Ch3MS-RF, a machine-learning-based model to enable characterization of complex mixtures and prediction of structure-specific properties of unidentifiable organic compounds.
PubDate: 2022-06-24T23:18:49+02:00
- Measuring dry deposition of ammonia using flux-gradient and eddy
covariance methods with two novel open-path instruments
Abstract: Measuring dry deposition of ammonia using flux-gradient and eddy covariance methods with two novel open-path instruments
Daan Swart, Jun Zhang, Shelley van der Graaf, Susanna Rutledge-Jonker, Arjan Hensen, Stijn Berkhout, Pascal Wintjen, René van der Hoff, Marty Haaima, Arnoud Frumau, Pim van den Bulk, Ruben Schulte, and Thomas van Goethem
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2022-171,2022
Preprint under review for AMT (discussion: open, 0 comments)
During a five-week comparison campaign, we tested two setups that aim to measure half-hourly ammonia fluxes. The eddy covariance and flux gradient systems showed very similar results when the upwind terrain was both homogeneous and free of obstacles. We discuss the technical performance and practical limitations of both systems. Measurements from these instruments can facilitate the study of processes behind ammonia deposition, an important contributor to eutrophication in natural areas.
PubDate: 2022-06-24T23:18:49+02:00
- Performance of AIRS ozone retrieval over the central Himalayas: Case
studies of biomass burning, downward ozone transport and radiative forcing
using long-term observations
Abstract: Performance of AIRS ozone retrieval over the central Himalayas: Case studies of biomass burning, downward ozone transport and radiative forcing using long-term observations
Prajjwal Rawat, Manish Naja, Evan Fishbein, Pradeep K. Thapliyal, Rajesh Kumar, Piyush Bhardwaj, Aditya Jaiswal, Sugriva Nath Tiwari, Sethuraman Venkataramani, and Shyam Lal
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2022-187,2022
Preprint under review for AMT (discussion: open, 0 comments)
Satellite based ozone observations have gained wide importance due to their global coverage. However, satellite retrieved products are less direct and needs to be validated, particularly in complex terrain region. Here, ozonesonde launched from a Himalayan site is utilized to assess the Atmospheric Infrared Sounder (AIRS) ozone retrieval. AIRS is shown to overestimates ozone in the upper troposphere and lower stratosphere but does reasonably well in the lower troposphere and stratosphere.
PubDate: 2022-06-24T23:18:49+02:00
- High-frequency gaseous and particulate chemical characterization using
extractive electrospray ionization mass spectrometry (Dual-Phase-EESI-TOF)
Abstract: High-frequency gaseous and particulate chemical characterization using extractive electrospray ionization mass spectrometry (Dual-Phase-EESI-TOF)
Chuan Ping Lee, Mihnea Surdu, David M. Bell, Josef Dommen, Mao Xiao, Xueqin Zhou, Andrea Baccarini, Stamatios Giannoukos, Günther Wehrle, Pascal André Schneider, Andre S. H. Prevot, Jay G. Slowik, Houssni Lamkaddam, Dongyu Wang, Urs Baltensperger, and Imad El Haddad
Atmos. Meas. Tech., 15, 3747–3760, https://doi.org/10.5194/amt-15-3747-2022, 2022
Real-time detection of both the gas and particle phase is needed to elucidate the sources and chemical reaction pathways of organic vapors and particulate matter. The Dual-EESI was developed to measure gas- and particle-phase species to provide new insights into aerosol sources or formation mechanisms. After characterizing the relative gas and particle response factors of EESI via organic aerosol uptake experiments, the Dual-EESI is more sensitive toward gas-phase analyes.
PubDate: 2022-06-23T23:18:49+02:00
- Cloud phase and macrophysical properties over the Southern Ocean during
the MARCUS field campaign
Abstract: Cloud phase and macrophysical properties over the Southern Ocean during the MARCUS field campaign
Baike Xi, Xiquan Dong, Xiaojian Zheng, and Peng Wu
Atmos. Meas. Tech., 15, 3761–3777, https://doi.org/10.5194/amt-15-3761-2022, 2022
This study develops an innovative method to determine the cloud phases over the Southern Ocean (SO) using the combination of radar and lidar measurements during the ship-based field campaign of MARCUS. Results from our study show that the low-level, deep, and shallow cumuli are dominant, and the mixed-phase clouds occur more than single phases over the SO. The mixed-phase cloud properties are similar to liquid-phase (ice-phase) clouds in the midlatitudes (polar) region of the SO.
PubDate: 2022-06-23T23:18:49+02:00
- An optimal estimation-based retrieval of upper atmospheric oxygen airglow
and temperature from SCIAMACHY limb observations
Abstract: An optimal estimation-based retrieval of upper atmospheric oxygen airglow and temperature from SCIAMACHY limb observations
Kang Sun, Mahdi Yousefi, Christopher Chan Miller, Kelly Chance, Gonzalo González Abad, Iouli E. Gordon, Xiong Liu, Ewan O'Sullivan, Christopher E. Sioris, and Steven C. Wofsy
Atmos. Meas. Tech., 15, 3721–3745, https://doi.org/10.5194/amt-15-3721-2022, 2022
This study of upper atmospheric airglow from oxygen is motivated by the need to measure oxygen simultaneously with methane and CO2 in satellite remote sensing. We provide an accurate understanding of the spatial, temporal, and spectral distribution of airglow emissions, which will help in the satellite remote sensing of greenhouse gases and constraining the chemical and physical processes in the upper atmosphere.
PubDate: 2022-06-23T23:18:49+02:00
- An alternative cloud index for estimating downwelling surface solar
irradiance from various satellite imagers in the framework of a Heliosat-V
method
Abstract: An alternative cloud index for estimating downwelling surface solar irradiance from various satellite imagers in the framework of a Heliosat-V method
Benoît Tournadre, Benoît Gschwind, Yves-Marie Saint-Drenan, Xuemei Chen, Rodrigo Amaro E Silva, and Philippe Blanc
Atmos. Meas. Tech., 15, 3683–3704, https://doi.org/10.5194/amt-15-3683-2022, 2022
Solar radiation received by the Earth's surface is valuable information for various fields like the photovoltaic industry or climate research. Pictures taken from satellites can be used to estimate the solar radiation from cloud reflectivity. Two issues for a good estimation are different instrumentations and orbits. We modify a widely used method that is today only used on geostationary satellites, so it can be applied on instruments on different orbits and with different sensitivities.
PubDate: 2022-06-21T00:14:49+02:00
- A high-transmission axial ion mobility classifier for mass–mobility
measurements of atmospheric ions
Abstract: A high-transmission axial ion mobility classifier for mass–mobility measurements of atmospheric ions
Markus Leiminger, Lukas Fischer, Sophia Brilke, Julian Resch, Paul Martin Winkler, Armin Hansel, and Gerhard Steiner
Atmos. Meas. Tech., 15, 3705–3720, https://doi.org/10.5194/amt-15-3705-2022, 2022
We developed an axial ion mobility classifier coupled to an atmospheric-pressure interface time-of-flight (APi-TOF) mass spectrometer to measure size-segregated atmospheric ions. We characterize the performance of the novel instrument with bipolar-electrospray-generated ion mobility standards and compare the results with CFD simulations and a simplified numerical particle-tracking model. Ultimately, we report first mass–mobility measurements of atmospheric ions in Innsbruck, Austria.
PubDate: 2022-06-21T00:14:49+02:00
- Direct measurement of N2O5 heterogeneous uptake coefficients on ambient
aerosols via an aerosol flow tube system: design, characterization and
performance
Abstract: Direct measurement of N2O5 heterogeneous uptake coefficients on ambient aerosols via an aerosol flow tube system: design, characterization and performance
Xiaorui Chen, Haichao Wang, Tianyu Zhai, Chunmeng Li, and Keding Lu
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2022-167,2022
Preprint under review for AMT (discussion: open, 0 comments)
N2O5 is an important reservoir of atmospheric nitrogen, the interface reaction of which on ambient particles can largely influence the fate of nitrogen oxides and air quality. In this study, we developed an approach to enable the reactions of N2O5 on ambient particles directly in a tube-reactor and thus derive the reaction rate of this process by a chemistry model. Its successful application helps complement the data scarcity and fill the knowledge gap between laboratory and field results.
PubDate: 2022-06-21T00:14:49+02:00
- Detection of supercooled liquid water containing clouds with ceilometers:
development and evaluation of deterministic and data-driven retrievals
Abstract: Detection of supercooled liquid water containing clouds with ceilometers: development and evaluation of deterministic and data-driven retrievals
Adrien Guyot, Alain Protat, Simon P. Alexander, Andrew R. Klekociuk, Peter Kuma, and Adrian McDonald
Atmos. Meas. Tech., 15, 3663–3681, https://doi.org/10.5194/amt-15-3663-2022, 2022
Ceilometers are instruments that are widely deployed as part of operational networks. They are usually not able to detect cloud phase. Here, we propose an evaluation of various methods to detect supercooled liquid water with ceilometer observations, using an extensive dataset from Davis, Antarctica. Our results highlight the possibility for ceilometers to detect supercooled liquid water in clouds.
PubDate: 2022-06-20T00:14:49+02:00
- An Improved OSIRIS NO2 Profile Retrieval in the UTLS and Intercomparison
with ACE-FTS and SAGE III/ISS
Abstract: An Improved OSIRIS NO2 Profile Retrieval in the UTLS and Intercomparison with ACE-FTS and SAGE III/ISS
Kimberlee Dubé, Daniel Zawada, Adam Bourassa, Doug Degenstein, William Randel, David Flittner, Patrick Sheese, and Kaley Walker
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2022-133,2022
Preprint under review for AMT (discussion: open, 0 comments)
Satellite observations are important for monitoring changes in atmospheric composition. Here we describe an improved version of the NO2 retrieval for the Optical Spectrograph and InfraRed Imager System. The resulting NO2 profiles are compared to those from the Atmospheric Chemistry Experiment – Fourier Transform Spectrometer and the Stratospheric Aerosol and Gas Experiment III on the International Space Station. All datasets agree within 20 % throughout the stratosphere.
PubDate: 2022-06-20T00:14:49+02:00
- Horizontal geometry of trade wind cumuli – aircraft observations from a
shortwave infrared imager versus a radar profiler
Abstract: Horizontal geometry of trade wind cumuli – aircraft observations from a shortwave infrared imager versus a radar profiler
Henning Dorff, Heike Konow, and Felix Ament
Atmos. Meas. Tech., 15, 3641–3661, https://doi.org/10.5194/amt-15-3641-2022, 2022
This study elaborates how aircraft-based horizontal geometries of trade wind cumuli differ whether a one-dimensional profiling radar or a two-dimensional imager is used. Cloud size distributions are examined in terms of sensitivity to sample size, resolution, and instrument field of view. While the radar cannot reproduce the double power law distribution due to coarse resolution and restriction to vertical transects, the imager also reveals the elliptic cloud structure enhancing with wind speed.
PubDate: 2022-06-17T17:14:37+02:00
- Characterization of a modified printed optical particle spectrometer for
high-frequency and high-precision laboratory and field measurements
Abstract: Characterization of a modified printed optical particle spectrometer for high-frequency and high-precision laboratory and field measurements
Sabin Kasparoglu, Mohammad M. Islam, Nicholas Meskhidze, and Markus D. Petters
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2022-185,2022
Preprint under review for AMT (discussion: open, 0 comments)
A modified version of a Handix Scientific’s Printed Optical Particle Spectrometer is introduced. The manuscript presents characterization experiments, including concentration-, size-, and time-responses. Integration of an external multichannel analyzer card removes counting limitations of the original instrument. It is shown that the high-resolution light-scattering amplitude data can be used to sense particle phase transitions.
PubDate: 2022-06-17T17:14:37+02:00
- Uncertainty-bounded estimates of ash cloud properties using the ORAC
algorithm: Application to the 2019 Raikoke eruption
Abstract: Uncertainty-bounded estimates of ash cloud properties using the ORAC algorithm: Application to the 2019 Raikoke eruption
Andrew T. Prata, Roy G. Grainger, Isabelle A. Taylor, Adam C. Povey, Simon R. Proud, and Caroline A. Poulsen
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2022-166,2022
Preprint under review for AMT (discussion: open, 0 comments)
Satellite observations can be used to track volcanic ash clouds as well as estimate their height, particle sizes and mass; however, the techniques used to extract this information are always associated some uncertainty. Here we describe advances in a satellite-based technique that is used to estimate ash cloud properties of the June 2019 Raikoke (Russia) eruption. Our results are significant because ash warning centres will require uncertainty information in the future.
PubDate: 2022-06-17T17:14:37+02:00
- An all-sky camera image classification method using cloud cover features
Abstract: An all-sky camera image classification method using cloud cover features
Xiaotong Li, Baozhu Wang, Bo Qiu, and Chao Wu
Atmos. Meas. Tech., 15, 3629–3639, https://doi.org/10.5194/amt-15-3629-2022, 2022
The all-sky camera images can reflect the local cloud cover, which is considerable for astronomical observatory site selection. Therefore, the realization of automatic classification of the images is very important. In this paper, three cloud cover features are proposed to classify the images. The proposed method is evaluated on a large dataset, and the method achieves an accuracy of 96.58 % and F1_score of 96.24 %, which greatly improves the efficiency of automatic processing of the images.
PubDate: 2022-06-16T17:14:37+02:00
- Small scale variability of water vapor in the atmosphere: implications for
inter-comparison of data from different measuring systems
Abstract: Small scale variability of water vapor in the atmosphere: implications for inter-comparison of data from different measuring systems
Xavier Calbet, Cintia Carbajal Henken, Sergio DeSouza-Machado, Bomin Sun, and Tony Reale
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2022-111,2022
Preprint under review for AMT (discussion: open, 0 comments)
Water vapor concentration in the atmosphere at small scales (< 6 km) is considered. The measurements show a Gaussian random field behavior following Kolmogorov's theory of turbulence two-thirds law. These properties can be useful when estimating the water vapor variability within a given observed satellite scene or when different water vapor measurements have to be merged consistently.
PubDate: 2022-06-16T17:14:37+02:00
- Performance of open-path lasers and Fourier transform infrared
spectroscopic systems in agriculture emissions research
Abstract: Performance of open-path lasers and Fourier transform infrared spectroscopic systems in agriculture emissions research
Mei Bai, Zoe Loh, David W. T. Griffith, Debra Turner, Richard Eckard, Robert Edis, Owen T. Denmead, Glenn W. Bryant, Clare Paton-Walsh, Matthew Tonini, Sean M. McGinn, and Deli Chen
Atmos. Meas. Tech., 15, 3593–3610, https://doi.org/10.5194/amt-15-3593-2022, 2022
The open-path laser (OPL) and open-path Fourier transform infrared (OP-FTIR) are used in agricultural research, but their error in emissions research has not been the focus of studies. We conducted trace gas release trials and herd and paddock emission studies to compare their applicability and performance. The OP-FTIR has better stability in stable conditions than OPL. The CH4 OPL accurately detects the low background level of CH4, but the NH3 OPL only detects background values>10 ppbv.
PubDate: 2022-06-15T00:47:09+02:00
- Evaluation of two common source estimation measurement strategies using
large-eddy simulation of plume dispersion under neutral atmospheric
conditions
Abstract: Evaluation of two common source estimation measurement strategies using large-eddy simulation of plume dispersion under neutral atmospheric conditions
Anja Ražnjević, Chiel van Heerwaarden, and Maarten Krol
Atmos. Meas. Tech., 15, 3611–3628, https://doi.org/10.5194/amt-15-3611-2022, 2022
We evaluate two widely used observational techniques (Other Test Method (OTM) 33A and car drive-bys) that estimate point source gas emissions. We performed our analysis on high-resolution plume dispersion simulation. For car drive-bys we found that at least 15 repeated measurements were needed to get within 40 % of the true emissions. OTM 33A produced large errors in estimation (50 %–200 %) due to its sensitivity to dispersion coefficients and underlying simplifying assumptions.
PubDate: 2022-06-15T00:47:09+02:00
- Improved spectral processing for a multi-mode pulse compression Ka/Ku-band
cloud radar system
Abstract: Improved spectral processing for a multi-mode pulse compression Ka/Ku-band cloud radar system
Han Ding, Haoran Li, and Liping Liu
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2022-169,2022
Preprint under review for AMT (discussion: open, 0 comments)
In this study, a framework for processing the Doppler spectra observations of a multi-mode pulse compression Ka/Ku cloud radar system is presented. We first proposed an approach to identify and remove the clutter signals in the Doppler spectrum. Then, we developed a new algorithm to remove the range sidelobe at the modes implementing the pulse compression technique. The radar observations from different modes were then merged using the shift-then-average method.
PubDate: 2022-06-15T00:47:09+02:00
- ERUO: a spectral processing routine for the Micro Rain Radar PRO (MRR-PRO)
Abstract: ERUO: a spectral processing routine for the Micro Rain Radar PRO (MRR-PRO)
Alfonso Ferrone, Anne-Claire Billault-Roux, and Alexis Berne
Atmos. Meas. Tech., 15, 3569–3592, https://doi.org/10.5194/amt-15-3569-2022, 2022
The Micro Rain Radar PRO (MRR-PRO) is a meteorological radar, with a relevant set of features for deployment in remote locations. We developed an algorithm, named ERUO, for the processing of its measurements of snowfall. The algorithm addresses typical issues of the raw spectral data, such as interference lines, but also improves the quality and sensitivity of the radar variables. ERUO has been evaluated over four different datasets collected in Antarctica and in the Swiss Jura.
PubDate: 2022-06-14T00:47:09+02:00
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