Pub Date : 2024-06-24DOI: 10.5194/egusphere-2024-1763
Sarah E. Hancock, Daniel Jacob, Zichong Chen, Hannah Nesser, Aaron Davitt, Daniel J. Varon, Melissa P. Sulprizio, Nicholas Balasus, Lucas A. Estrada, James D. East, Elise Penn, Cynthia A. Randles, John Worden, Ilse Aben, Robert J. Parker, Joannes D. Maasakkers
Abstract. We use 2021 TROPOMI and GOSAT satellite observations of atmospheric methane in an analytical inversion to quantify national methane emissions from South America at up to 25 km × 25 km resolution. From the inversion, we derive optimal posterior estimates of methane emissions correcting the national anthropogenic emission inventories reported by individual countries to the United Nations Framework Convention on Climate Change (UNFCCC) and taken here as prior estimates. We also evaluate two alternative wetland emission inventories (WetCHARTs and LPJ-wsl) as prior estimates. Our best posterior estimates for wetland emissions are consistent with previous inventories for the Amazon but lower for the Pantanal and higher for the Parana. Our best posterior estimate of South American anthropogenic emissions is 48 (41–56) Tg a-1, where numbers in parentheses are the range from our inversion ensemble. This is 55 % higher than UNFCCC reports and is dominated by livestock (65 % of anthropogenic total). We find that TROPOMI and GOSAT observations can effectively optimize and separate national emissions by sector for 10 of the 13 countries and territories in the region, 7 of which account for 93 % of continental anthropogenic emissions: Brazil (19 (16–23) Tg a−1), Argentina (9.2 (7.9–11) Tg a−1 ), Venezuela (7.0 (5.5-9.9) Tg a−1), Colombia (5.0 (4.4–6.7) Tg a−1), Peru (2.4 (1.6–3.9) Tg a−1), Bolivia (0.96 (0.66–1.2) Tg a−1), and Paraguay (0.93 (0.88 – 1.0) Tg a−1). Our estimates align with UNFCCC reports for Brazil, Bolivia, and Paraguay, but are significantly higher for other countries. Emissions in all countries are dominated by livestock (mainly enteric fermentation) except for oil/gas in Venezuela and landfills in Peru. Methane intensities from the oil/gas industry are high in Venezuela (33 %), Colombia (6.5 %) and Argentina (5.9 %). Country-average emission factors for enteric fermentation from cattle in UNFCCC reports are in the range 46–60 kg head-1 a-1, close to the IPCC Tier 1 estimate which is mostly based on data from Brazil. Our inversion yields cattle enteric fermentation emission factors consistent with the UNFCCC reports for Brazil and Bolivia but a factor of two higher for other countries. The discrepancy for Argentina can be corrected by using IPCC Tier 2 emission estimates accounting for high milk production.
{"title":"Satellite quantification of methane emissions from South American countries: A high-resolution inversion of TROPOMI and GOSAT observations","authors":"Sarah E. Hancock, Daniel Jacob, Zichong Chen, Hannah Nesser, Aaron Davitt, Daniel J. Varon, Melissa P. Sulprizio, Nicholas Balasus, Lucas A. Estrada, James D. East, Elise Penn, Cynthia A. Randles, John Worden, Ilse Aben, Robert J. Parker, Joannes D. Maasakkers","doi":"10.5194/egusphere-2024-1763","DOIUrl":"https://doi.org/10.5194/egusphere-2024-1763","url":null,"abstract":"<strong>Abstract.</strong> We use 2021 TROPOMI and GOSAT satellite observations of atmospheric methane in an analytical inversion to quantify national methane emissions from South America at up to 25 km × 25 km resolution. From the inversion, we derive optimal posterior estimates of methane emissions correcting the national anthropogenic emission inventories reported by individual countries to the United Nations Framework Convention on Climate Change (UNFCCC) and taken here as prior estimates. We also evaluate two alternative wetland emission inventories (WetCHARTs and LPJ-wsl) as prior estimates. Our best posterior estimates for wetland emissions are consistent with previous inventories for the Amazon but lower for the Pantanal and higher for the Parana. Our best posterior estimate of South American anthropogenic emissions is 48 (41–56) Tg a<sup>-1</sup>, where numbers in parentheses are the range from our inversion ensemble. This is 55 % higher than UNFCCC reports and is dominated by livestock (65 % of anthropogenic total). We find that TROPOMI and GOSAT observations can effectively optimize and separate national emissions by sector for 10 of the 13 countries and territories in the region, 7 of which account for 93 % of continental anthropogenic emissions: Brazil (19 (16–23) Tg a<sup>−1</sup>), Argentina (9.2 (7.9–11) Tg a<sup>−1</sup> ), Venezuela (7.0 (5.5-9.9) Tg a<sup>−1</sup>), Colombia (5.0 (4.4–6.7) Tg a<sup>−1</sup>), Peru (2.4 (1.6–3.9) Tg a<sup>−1</sup>), Bolivia (0.96 (0.66–1.2) Tg a<sup>−1</sup>), and Paraguay (0.93 (0.88 – 1.0) Tg a<sup>−1</sup>). Our estimates align with UNFCCC reports for Brazil, Bolivia, and Paraguay, but are significantly higher for other countries. Emissions in all countries are dominated by livestock (mainly enteric fermentation) except for oil/gas in Venezuela and landfills in Peru. Methane intensities from the oil/gas industry are high in Venezuela (33 %), Colombia (6.5 %) and Argentina (5.9 %). Country-average emission factors for enteric fermentation from cattle in UNFCCC reports are in the range 46–60 kg head<sup>-1</sup> a<sup>-1</sup>, close to the IPCC Tier 1 estimate which is mostly based on data from Brazil. Our inversion yields cattle enteric fermentation emission factors consistent with the UNFCCC reports for Brazil and Bolivia but a factor of two higher for other countries. The discrepancy for Argentina can be corrected by using IPCC Tier 2 emission estimates accounting for high milk production.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"61 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141444769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-21DOI: 10.5194/acp-24-7137-2024
Kevin Oliveira, Marc Guevara, Oriol Jorba, Hervé Petetin, Dene Bowdalo, Carles Tena, Gilbert Montané Pinto, Franco López, Carlos Pérez García-Pando
Abstract. Volatile organic compounds (VOCs) significantly impact air quality and atmospheric chemistry, influencing ozone formation and secondary organic aerosol production. Despite their importance, the uncertainties associated with representing VOCs in atmospheric emission inventories are considerable. This work presents a spatiotemporal assessment and evaluation of benzene, toluene, and xylene (BTX) emissions and concentrations in Spain by combining bottom-up emissions, air quality modelling techniques, and ground-based observations. The emissions produced by High-Elective Resolution Modelling Emission System (HERMESv3) were used as input to the Multiscale Online Nonhydrostatic AtmospheRe CHemistry (MONARCH) chemical transport model to simulate surface concentrations across Spain. Comparing modelled and observed levels revealed uncertainty in the anthropogenic emissions, which were further explored through sensitivity tests. The largest levels of observed benzene and xylene were found in industrial sites near coke ovens, refineries, and car manufacturing facilities, where the modelling results show large underestimations. Official emissions reported for these facilities were replaced by alternative estimates, resulting in varied improvements in the model's performance across different stations. However, uncertainties associated with industrial emission processes persist, emphasising the need for further refinement. For toluene, consistent overestimations in background stations were mainly related to uncertainties in the spatial disaggregation of emissions from industrial-use solvent activities, mainly wood paint applications. Observed benzene levels in Barcelona's urban traffic areas were 5 times larger than the ones observed in Madrid. MONARCH failed to reproduce the observed gradient between the two cities due to uncertainties arising from estimating emissions from motorcycles and mopeds, as well as from different measurement methods and the model's capacity to accurately simulate meteorological conditions. Our results are constrained by the spatial and temporal coverage of available BTX observations, posing a key challenge in evaluating the spatial distribution of modelled levels and associated emissions.
{"title":"On the uncertainty of anthropogenic aromatic volatile organic compound emissions: model evaluation and sensitivity analysis","authors":"Kevin Oliveira, Marc Guevara, Oriol Jorba, Hervé Petetin, Dene Bowdalo, Carles Tena, Gilbert Montané Pinto, Franco López, Carlos Pérez García-Pando","doi":"10.5194/acp-24-7137-2024","DOIUrl":"https://doi.org/10.5194/acp-24-7137-2024","url":null,"abstract":"Abstract. Volatile organic compounds (VOCs) significantly impact air quality and atmospheric chemistry, influencing ozone formation and secondary organic aerosol production. Despite their importance, the uncertainties associated with representing VOCs in atmospheric emission inventories are considerable. This work presents a spatiotemporal assessment and evaluation of benzene, toluene, and xylene (BTX) emissions and concentrations in Spain by combining bottom-up emissions, air quality modelling techniques, and ground-based observations. The emissions produced by High-Elective Resolution Modelling Emission System (HERMESv3) were used as input to the Multiscale Online Nonhydrostatic AtmospheRe CHemistry (MONARCH) chemical transport model to simulate surface concentrations across Spain. Comparing modelled and observed levels revealed uncertainty in the anthropogenic emissions, which were further explored through sensitivity tests. The largest levels of observed benzene and xylene were found in industrial sites near coke ovens, refineries, and car manufacturing facilities, where the modelling results show large underestimations. Official emissions reported for these facilities were replaced by alternative estimates, resulting in varied improvements in the model's performance across different stations. However, uncertainties associated with industrial emission processes persist, emphasising the need for further refinement. For toluene, consistent overestimations in background stations were mainly related to uncertainties in the spatial disaggregation of emissions from industrial-use solvent activities, mainly wood paint applications. Observed benzene levels in Barcelona's urban traffic areas were 5 times larger than the ones observed in Madrid. MONARCH failed to reproduce the observed gradient between the two cities due to uncertainties arising from estimating emissions from motorcycles and mopeds, as well as from different measurement methods and the model's capacity to accurately simulate meteorological conditions. Our results are constrained by the spatial and temporal coverage of available BTX observations, posing a key challenge in evaluating the spatial distribution of modelled levels and associated emissions.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"41 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141435788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-21DOI: 10.5194/egusphere-2024-1725
Fabian Hoffmann, Franziska Glassmeier, Graham Feingold
Abstract. Aerosol-cloud interactions modulate the role of clouds in Earth's climate. We derive, evaluate, and apply a simple model to understand aerosol-mediated cloud water adjustments in stratocumulus based on only two prognostic equations for the integrated cloud water L and droplet number concentration N. The model is solved numerically and analytically, and agrees well with documented large-eddy simulation data and satellite retrievals. A tight relationship between adjustments at low and high N is found, revealing the influence of non-precipitation processes (primarily entrainment) on adjustments in precipitating clouds. Furthermore, it is shown that adjustments in non-precipitating clouds tend to be positively biased by external L or N perturbations, while adjustments in precipitating clouds are barely susceptible. By deliberately reducing the complexity of the underlying system, this study constitutes a way forward to facilitate process-level understanding of cloud water adjustments.
摘要气溶胶与云的相互作用调节着云在地球气候中的作用。我们推导、评估并应用了一个简单的模型来理解气溶胶介导的层积云云水调整，该模型仅基于综合云水 L 和水滴数浓度 N 的两个预报方程。研究发现，低 N 值和高 N 值的调整之间关系密切，揭示了非沉降过程（主要是夹带）对降水云调整的影响。此外，研究还表明，非沉降云的调整往往会受到外部L或N扰动的正偏影响，而沉降云的调整则几乎不受影响。通过有意降低基本系统的复杂性，本研究为促进对云水调节过程的理解提供了一条前进的道路。
{"title":"The Impact of Aerosol on Cloud Water: A Heuristic Perspective","authors":"Fabian Hoffmann, Franziska Glassmeier, Graham Feingold","doi":"10.5194/egusphere-2024-1725","DOIUrl":"https://doi.org/10.5194/egusphere-2024-1725","url":null,"abstract":"<strong>Abstract.</strong> Aerosol-cloud interactions modulate the role of clouds in Earth's climate. We derive, evaluate, and apply a simple model to understand aerosol-mediated cloud water adjustments in stratocumulus based on only two prognostic equations for the integrated cloud water <em>L</em> and droplet number concentration <em>N</em>. The model is solved numerically and analytically, and agrees well with documented large-eddy simulation data and satellite retrievals. A tight relationship between adjustments at low and high <em>N</em> is found, revealing the influence of non-precipitation processes (primarily entrainment) on adjustments in precipitating clouds. Furthermore, it is shown that adjustments in non-precipitating clouds tend to be positively biased by external <em>L</em> or <em>N</em> perturbations, while adjustments in precipitating clouds are barely susceptible. By deliberately reducing the complexity of the underlying system, this study constitutes a way forward to facilitate process-level understanding of cloud water adjustments.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"43 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141435794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-21DOI: 10.5194/egusphere-2024-1617
Natalie M. Mahowald, Longlei Li, Julius Vira, Marje Prank, Douglas S. Hamilton, Hitoshi Matsui, Ron L. Miller, Louis Lu, Ezgi Akyuz, Daphne Meidan, Peter G. Hess, Heikki Lihavainen, Christine Wiedinmyer, Jenny Hand, Maria Grazia Alaimo, Célia Alves, Andres Alastuey, Paulo Artaxo, Africa Barreto, Francisco Barraza, Silvia Becagli, Giulia Calzolai, Shankararaman Chellam, Ying Chen, Patrick Chuang, David D. Cohen, Cristina Colombi, Evangelia Diapouli, Gaetano Dongarra, Konstantinos Eleftheriadis, Johann Engelbrecht, Corinne Galy-Lacaux, Cassandra Gaston, Dario Gomez, Yenny González Ramos, Roy M. Harrison, Chris Heyes, Barak Herut, Philip Hopke, Christoph Hüglin, Maria Kanakidou, Zsofia Kertesz, Zbigniew Klimont, Katriina Kyllönen, Fabrice Lambert, Xiaohong Liu, Remi Losno, Franco Lucarelli, Willy Maenhaut, Beatrice Marticorena, Randall V. Martin, Nikolaos Mihalopoulos, Yasser Morera-Gomez, Adina Paytan, Joseph Prospero, Sergio Rodríguez, Patricia Smichowski, Daniela Varrica, Brenna Walsh, Crystal Weagle, Xi Zhao
Abstract. Aerosol particles are an important part of the Earth system, but their concentrations are spatially and temporally heterogeneous, as well as variable in size and composition. Particles can interact with incoming solar radiation and outgoing long wave radiation, change cloud properties, affect photochemistry, impact surface air quality, change the surface albedo of snow and ice, and modulate carbon dioxide uptake by the land and ocean. High particulate matter concentrations at the surface represent an important public health hazard. There are substantial datasets describing aerosol particles in the literature or in public health databases, but they have not been compiled for easy use by the climate and air quality modelling community. Here we present a new compilation of PM2.5 and PM10 aerosol observations, focusing on the spatial variability across different observational stations, including composition, and demonstrate a method for comparing the datasets to model output. Overall, most of the planet or even the land fraction does not have sufficient observations of surface concentrations, and especially particle composition to understand the current distribution of particles. Most climate models exclude 10–30 % of the aerosol particles in both PM2.5 and PM10 size fractions across large swaths of the globe in their current configurations, with ammonium nitrate and agricultural dust aerosol being the most important omitted aerosol types.
{"title":"AERO-MAP: A data compilation and modelling approach to understand spatial variability in fine and coarse mode aerosol composition","authors":"Natalie M. Mahowald, Longlei Li, Julius Vira, Marje Prank, Douglas S. Hamilton, Hitoshi Matsui, Ron L. Miller, Louis Lu, Ezgi Akyuz, Daphne Meidan, Peter G. Hess, Heikki Lihavainen, Christine Wiedinmyer, Jenny Hand, Maria Grazia Alaimo, Célia Alves, Andres Alastuey, Paulo Artaxo, Africa Barreto, Francisco Barraza, Silvia Becagli, Giulia Calzolai, Shankararaman Chellam, Ying Chen, Patrick Chuang, David D. Cohen, Cristina Colombi, Evangelia Diapouli, Gaetano Dongarra, Konstantinos Eleftheriadis, Johann Engelbrecht, Corinne Galy-Lacaux, Cassandra Gaston, Dario Gomez, Yenny González Ramos, Roy M. Harrison, Chris Heyes, Barak Herut, Philip Hopke, Christoph Hüglin, Maria Kanakidou, Zsofia Kertesz, Zbigniew Klimont, Katriina Kyllönen, Fabrice Lambert, Xiaohong Liu, Remi Losno, Franco Lucarelli, Willy Maenhaut, Beatrice Marticorena, Randall V. Martin, Nikolaos Mihalopoulos, Yasser Morera-Gomez, Adina Paytan, Joseph Prospero, Sergio Rodríguez, Patricia Smichowski, Daniela Varrica, Brenna Walsh, Crystal Weagle, Xi Zhao","doi":"10.5194/egusphere-2024-1617","DOIUrl":"https://doi.org/10.5194/egusphere-2024-1617","url":null,"abstract":"<strong>Abstract.</strong> Aerosol particles are an important part of the Earth system, but their concentrations are spatially and temporally heterogeneous, as well as variable in size and composition. Particles can interact with incoming solar radiation and outgoing long wave radiation, change cloud properties, affect photochemistry, impact surface air quality, change the surface albedo of snow and ice, and modulate carbon dioxide uptake by the land and ocean. High particulate matter concentrations at the surface represent an important public health hazard. There are substantial datasets describing aerosol particles in the literature or in public health databases, but they have not been compiled for easy use by the climate and air quality modelling community. Here we present a new compilation of PM<sub>2.5 </sub>and PM<sub>10</sub> aerosol observations, focusing on the spatial variability across different observational stations, including composition, and demonstrate a method for comparing the datasets to model output. Overall, most of the planet or even the land fraction does not have sufficient observations of surface concentrations, and especially particle composition to understand the current distribution of particles. Most climate models exclude 10–30 % of the aerosol particles in both PM<sub>2.5 </sub>and PM<sub>10</sub> size fractions across large swaths of the globe in their current configurations, with ammonium nitrate and agricultural dust aerosol being the most important omitted aerosol types.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"18 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141435842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-21DOI: 10.5194/acp-24-7123-2024
Nan Sun, Gaopeng Lu, Yunfei Fu
Abstract. We examine the geographical distribution and microphysical three-dimensional structure of convective overshooting over East China by matching the Global Precipitation Measurement Dual-frequency Precipitation Radar (GPM DPR) instrument with the European Centre for Medium-Range Weather Forecasts Fifth-Generation Reanalysis (ERA5). Convective overshooting mainly occurs over Northeast China (NC) and northern Middle and East China (MEC), and its frequency varies from 4×10-4 to 5.4×10-3. Radar reflectivity of convective overshooting over NC accounts for a higher proportion below the freezing level, while MEC and South China (SC) account for a higher proportion above the freezing level, indicating stronger upward motion and more ice crystal particles. The microphysical processes within convective overshooting are unique, leading to various properties of the droplets in precipitation. Droplets of convective overshooting are large but sparse, with an effective droplet radius of nearly 2.5 mm below 10 km, which is about twice that of non-overshooting precipitation. The findings of this study may have important implications for the microphysical evolution associated with convective overshooting and provide more accurate precipitation microphysical parameters as input for model simulations.
{"title":"Microphysical characteristics of precipitation within convective overshooting over East China observed by GPM DPR and ERA5","authors":"Nan Sun, Gaopeng Lu, Yunfei Fu","doi":"10.5194/acp-24-7123-2024","DOIUrl":"https://doi.org/10.5194/acp-24-7123-2024","url":null,"abstract":"Abstract. We examine the geographical distribution and microphysical three-dimensional structure of convective overshooting over East China by matching the Global Precipitation Measurement Dual-frequency Precipitation Radar (GPM DPR) instrument with the European Centre for Medium-Range Weather Forecasts Fifth-Generation Reanalysis (ERA5). Convective overshooting mainly occurs over Northeast China (NC) and northern Middle and East China (MEC), and its frequency varies from 4×10-4 to 5.4×10-3. Radar reflectivity of convective overshooting over NC accounts for a higher proportion below the freezing level, while MEC and South China (SC) account for a higher proportion above the freezing level, indicating stronger upward motion and more ice crystal particles. The microphysical processes within convective overshooting are unique, leading to various properties of the droplets in precipitation. Droplets of convective overshooting are large but sparse, with an effective droplet radius of nearly 2.5 mm below 10 km, which is about twice that of non-overshooting precipitation. The findings of this study may have important implications for the microphysical evolution associated with convective overshooting and provide more accurate precipitation microphysical parameters as input for model simulations.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"75 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141435834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-21DOI: 10.5194/egusphere-2024-1676
Jakob Boyd Pernov, Jens Liengaard Hjorth, Lise Lotte Sørensen, Henrik Skov
Abstract. Ozone depletion events (ODEs) occur every spring in the Arctic and have implications for the atmospheric oxidizing capacity, radiative balance, and mercury oxidation. Here we comprehensively analyze ozone, ODEs, and their connection to meteorological and air mass history variables through statistical analyses, back-trajectories, and machine learning (ML) from observations at Villum Research Station, Station Nord, Greenland. We show that the ODE frequency and duration peak in May followed by April and March, which is likely related to air masses spending more time over sea ice and increases in radiation from March to May. Back-trajectories indicate that, as spring progresses, ODE air masses spend more time within the mixed layer and the geographic origins move closer to Villum. ODE frequency and duration are increasing during May (low confidence) and April (high confidence), respectively. Our analysis revealed that ODEs are favorable under sunny, calm conditions with air masses arriving from northerly wind directions with sea ice contact. The ML model was able to reproduce the ODE occurrence and illuminated that radiation, time over sea ice, and temperature were the most important variables for modeling ODEs during March, April, and May, respectively. Several variables displayed threshold ranges for contributing to the positive prediction of ODEs vs Non-ODEs, notably temperature, radiation, wind direction, time spent over sea ice, and snow. Our ML methodology provides a framework for investigating and comparing the environmental drivers of ODEs between different Arctic sites and can be applied to other atmospheric phenomena (e.g., atmospheric mercury depletion events).
{"title":"On the dynamics of ozone depletion events at Villum Research Station in the High Arctic","authors":"Jakob Boyd Pernov, Jens Liengaard Hjorth, Lise Lotte Sørensen, Henrik Skov","doi":"10.5194/egusphere-2024-1676","DOIUrl":"https://doi.org/10.5194/egusphere-2024-1676","url":null,"abstract":"<strong>Abstract.</strong> Ozone depletion events (ODEs) occur every spring in the Arctic and have implications for the atmospheric oxidizing capacity, radiative balance, and mercury oxidation. Here we comprehensively analyze ozone, ODEs, and their connection to meteorological and air mass history variables through statistical analyses, back-trajectories, and machine learning (ML) from observations at Villum Research Station, Station Nord, Greenland. We show that the ODE frequency and duration peak in May followed by April and March, which is likely related to air masses spending more time over sea ice and increases in radiation from March to May. Back-trajectories indicate that, as spring progresses, ODE air masses spend more time within the mixed layer and the geographic origins move closer to Villum. ODE frequency and duration are increasing during May (low confidence) and April (high confidence), respectively. Our analysis revealed that ODEs are favorable under sunny, calm conditions with air masses arriving from northerly wind directions with sea ice contact. The ML model was able to reproduce the ODE occurrence and illuminated that radiation, time over sea ice, and temperature were the most important variables for modeling ODEs during March, April, and May, respectively. Several variables displayed threshold ranges for contributing to the positive prediction of ODEs vs Non-ODEs, notably temperature, radiation, wind direction, time spent over sea ice, and snow. Our ML methodology provides a framework for investigating and comparing the environmental drivers of ODEs between different Arctic sites and can be applied to other atmospheric phenomena (e.g., atmospheric mercury depletion events).","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"74 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141435728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract. Volatile chemical products (VCPs) have become an important source of reactive organic gases (ROGs) in urban areas worldwide. Industrial activities can also utilize a large number of VCPs and emit many organic gases into the atmosphere. Due to multiple sampling and measurement challenges, only a subset of ROG species is usually measured for many industrial VCP sources. This study aims to investigate the emissions of ROGs from five industrial VCP sources in the Pearl River Delta (PRD) region of China, including the shoemaking, plastic surface coating, furniture coating, printing, and ship coating industries. A more comprehensive speciation of ROG emissions from these industrial VCP sources was developed by the combination of proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS) and the gas chromatography–mass spectrometer/flame ionization detector (GC–MS/FID). Our study identified oxygenated ROG species (OVOCs) as representative ROGs emitted from these sources, which are highly related to specific chemicals used during industrial activities. Moreover, mass spectra similarity analysis revealed significant dissimilarities among the ROG emissions from industrial activities, indicating substantial variations between different industrial VCP sources. Except for the ship coating industry utilizing solvent-borne coatings, the proportions of OVOCs range from 67 % to 96 % in total ROG emissions and 72 % to 97 % in total OH reactivity (OHR) for different industrial sources, while the corresponding contributions of OVOCs in the ship coating industry are only 16 ± 3.5 % and 15 ± 3.6 %. The industrial VCP sources associated with solvent-borne coatings exhibited a higher ozone formation potential (OFP), reaching as high as 5.5 and 2.7 g O3 g−1 ROGs for the ship coating and furniture coating industries, primarily due to contributions from aromatics. We find that a few species can contribute the majority of the ROG emissions and also their OHR and OFP from various industrial VCP sources. Our results suggest that ROG treatment devices may have limited effectiveness for all ROGs, with treatment efficiencies ranging from −12 % to 68 %. Furthermore, we found that ambient measurements in industrial areas have been significantly impacted by industrial VCP sources, and ROG pairs (e.g., methyl ethyl ketone (MEK) / C8 aromatics ratio) can be utilized as reliable evidence by using high-time-resolution ROG measurements from PTR-ToF-MS. Our study demonstrated the importance of measuring a large number of ROGs using PTR-ToF-MS for characterizing ROG emissions from industrial VCP sources.
{"title":"Emission characteristics of reactive organic gases (ROGs) from industrial volatile chemical products (VCPs) in the Pearl River Delta (PRD), China","authors":"Sihang Wang, Bin Yuan, Xianjun He, Ru Cui, Xin Song, Yubin Chen, Caihong Wu, Chaomin Wang, Yibo Huangfu, Xiao-Bing Li, Boguang Wang, Min Shao","doi":"10.5194/acp-24-7101-2024","DOIUrl":"https://doi.org/10.5194/acp-24-7101-2024","url":null,"abstract":"Abstract. Volatile chemical products (VCPs) have become an important source of reactive organic gases (ROGs) in urban areas worldwide. Industrial activities can also utilize a large number of VCPs and emit many organic gases into the atmosphere. Due to multiple sampling and measurement challenges, only a subset of ROG species is usually measured for many industrial VCP sources. This study aims to investigate the emissions of ROGs from five industrial VCP sources in the Pearl River Delta (PRD) region of China, including the shoemaking, plastic surface coating, furniture coating, printing, and ship coating industries. A more comprehensive speciation of ROG emissions from these industrial VCP sources was developed by the combination of proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS) and the gas chromatography–mass spectrometer/flame ionization detector (GC–MS/FID). Our study identified oxygenated ROG species (OVOCs) as representative ROGs emitted from these sources, which are highly related to specific chemicals used during industrial activities. Moreover, mass spectra similarity analysis revealed significant dissimilarities among the ROG emissions from industrial activities, indicating substantial variations between different industrial VCP sources. Except for the ship coating industry utilizing solvent-borne coatings, the proportions of OVOCs range from 67 % to 96 % in total ROG emissions and 72 % to 97 % in total OH reactivity (OHR) for different industrial sources, while the corresponding contributions of OVOCs in the ship coating industry are only 16 ± 3.5 % and 15 ± 3.6 %. The industrial VCP sources associated with solvent-borne coatings exhibited a higher ozone formation potential (OFP), reaching as high as 5.5 and 2.7 g O3 g−1 ROGs for the ship coating and furniture coating industries, primarily due to contributions from aromatics. We find that a few species can contribute the majority of the ROG emissions and also their OHR and OFP from various industrial VCP sources. Our results suggest that ROG treatment devices may have limited effectiveness for all ROGs, with treatment efficiencies ranging from −12 % to 68 %. Furthermore, we found that ambient measurements in industrial areas have been significantly impacted by industrial VCP sources, and ROG pairs (e.g., methyl ethyl ketone (MEK) / C8 aromatics ratio) can be utilized as reliable evidence by using high-time-resolution ROG measurements from PTR-ToF-MS. Our study demonstrated the importance of measuring a large number of ROGs using PTR-ToF-MS for characterizing ROG emissions from industrial VCP sources.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"35 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141430348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-20DOI: 10.5194/acp-24-7063-2024
Arianna Peron, Martin Graus, Marcus Striednig, Christian Lamprecht, Georg Wohlfahrt, Thomas Karl
Abstract. The anthropogenic and biogenic contributions of isoprene, monoterpenes, sesquiterpenes and methanol in an urban area were estimated based on direct eddy covariance flux observations during four campaigns between 2018 and 2021. While these compounds are typically thought to be dominated by biogenic sources on regional and global scales, the role of potentially significant anthropogenic emissions in urban areas has been recently debated. Typical fluxes of isoprene, monoterpenes and sesquiterpenes were on the order of 0.07 ± 0.02, 0.09 and 0.003 nmol m−2 s−1 during spring. During summer, emission fluxes of isoprene, monoterpenes and sesquiterpenes were higher on the order of 0.85 ± 0.09, 0.11 and 0.004 nmol m−2 s−1. It was found that the contribution of the anthropogenic part is strongly seasonally dependent. For isoprene, the anthropogenic fraction can be as high as 64 % in spring but is typically very low < 18 % during the summer season. For monoterpenes, the anthropogenic fraction was estimated to be between 43 % in spring and less than 20 % in summer. With values of 2.8 nmol m−2 s−1 in spring and 3.2 nmol m−2 s−1 in summer, methanol did not exhibit a significant seasonal variation of observed surface fluxes. However, there was a difference in emissions between weekdays and weekends (about 2.3 times higher on weekdays in spring). This suggests that methanol emissions are likely influenced by anthropogenic activities during all seasons.
{"title":"Deciphering anthropogenic and biogenic contributions to selected non-methane volatile organic compound emissions in an urban area","authors":"Arianna Peron, Martin Graus, Marcus Striednig, Christian Lamprecht, Georg Wohlfahrt, Thomas Karl","doi":"10.5194/acp-24-7063-2024","DOIUrl":"https://doi.org/10.5194/acp-24-7063-2024","url":null,"abstract":"Abstract. The anthropogenic and biogenic contributions of isoprene, monoterpenes, sesquiterpenes and methanol in an urban area were estimated based on direct eddy covariance flux observations during four campaigns between 2018 and 2021. While these compounds are typically thought to be dominated by biogenic sources on regional and global scales, the role of potentially significant anthropogenic emissions in urban areas has been recently debated. Typical fluxes of isoprene, monoterpenes and sesquiterpenes were on the order of 0.07 ± 0.02, 0.09 and 0.003 nmol m−2 s−1 during spring. During summer, emission fluxes of isoprene, monoterpenes and sesquiterpenes were higher on the order of 0.85 ± 0.09, 0.11 and 0.004 nmol m−2 s−1. It was found that the contribution of the anthropogenic part is strongly seasonally dependent. For isoprene, the anthropogenic fraction can be as high as 64 % in spring but is typically very low < 18 % during the summer season. For monoterpenes, the anthropogenic fraction was estimated to be between 43 % in spring and less than 20 % in summer. With values of 2.8 nmol m−2 s−1 in spring and 3.2 nmol m−2 s−1 in summer, methanol did not exhibit a significant seasonal variation of observed surface fluxes. However, there was a difference in emissions between weekdays and weekends (about 2.3 times higher on weekdays in spring). This suggests that methanol emissions are likely influenced by anthropogenic activities during all seasons.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"48 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141430347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract. Organic aerosol (OA) is a significant constituent of urban particulate matter (PM), and molecular markers therein provide information on the sources and formation mechanisms. With the in situ measurement of over 70 OA molecular markers in a summer month at a bihourly resolution, this study focused on the temporal variations in representative markers and dynamic source contributions to OA at an urban site in Hong Kong SAR (HK). The levels of secondary OA (SOA) markers were markedly elevated (p < 0.05) in the short-duration cases with continental and coastal air relative to those in the most common marine air, and the primary markers primarily contained local characteristics. The troughs showed the enhancements of many SOA markers (p < 0.05), which appeared to be related to the high relative humidity. The diurnal patterns of 2-methyltetrols varied in differed cases, and their aqueous formation at night seemed plausible, particularly in the presence of troughs. Eight sources were identified for the organic matter in submicron PM (PM1-OM). Despite being an urban site, the mean SOA contribution (66.1 ± 10.5 %), primarily anthropogenic, was significant. Anthropogenic SOA dominated in the cases with continental and coastal air and in the early afternoon. Local cooking and vehicle emissions became predominant in the case of marine air without troughs. Even averaged over the study period in this summer month with the prevalence of marine air, primary cooking emissions contributed up to 44.2 % to PM1-OM in the early evening. The study highlighted the need to control regional anthropogenic SOA and local cooking emissions to mitigate PM pollution in HK.
摘要。有机气溶胶（OA）是城市颗粒物（PM）的重要组成部分，其中的分子标记提供了有关其来源和形成机制的信息。这项研究以每两小时一次的分辨率，在一个夏季月份原位测量了超过 70 个有机气溶胶分子标记，重点研究了香港特别行政区（香港）一个市区地点的代表性标记的时间变化和有机气溶胶的动态来源贡献。与最常见的海洋空气相比，在大陆和沿海空气的短时情况下，二次 OA（SOA）标记物的水平明显升高（p < 0.05），而一次标记物主要包含本地特征。低谷显示了许多 SOA 标记的增强（p < 0.05），这似乎与高相对湿度有关。在不同的情况下，2-甲基四醇的昼夜模式各不相同，它们在夜间的水形成似乎是合理的，尤其是在出现低谷的情况下。亚微米级可吸入颗粒物（PM1-OM）中的有机物有八个来源。尽管这是一个城市站点，但 SOA 的平均贡献率（66.1 ± 10.5 %）非常高，主要是人为的。在有大陆和沿海空气的情况下，以及在下午早些时候，人为 SOA 占主导地位。在没有低谷的海洋空气中，本地烹饪和汽车尾气排放占主导地位。即使是在研究期间的平均值，在这个夏季海洋空气盛行的月份，一次烹饪排放对傍晚 PM1-OM 的影响高达 44.2%。这项研究强调有必要控制区域人为的 SOA 和本地烹饪排放，以减轻香港的 PM 污染。
{"title":"In situ measurement of organic aerosol molecular markers in urban Hong Kong during a summer period: temporal variations and source apportionment","authors":"Hongyong Li, Xiaopu Lyu, Likun Xue, Yunxi Huo, Dawen Yao, Haoxian Lu, Hai Guo","doi":"10.5194/acp-24-7085-2024","DOIUrl":"https://doi.org/10.5194/acp-24-7085-2024","url":null,"abstract":"Abstract. Organic aerosol (OA) is a significant constituent of urban particulate matter (PM), and molecular markers therein provide information on the sources and formation mechanisms. With the in situ measurement of over 70 OA molecular markers in a summer month at a bihourly resolution, this study focused on the temporal variations in representative markers and dynamic source contributions to OA at an urban site in Hong Kong SAR (HK). The levels of secondary OA (SOA) markers were markedly elevated (p < 0.05) in the short-duration cases with continental and coastal air relative to those in the most common marine air, and the primary markers primarily contained local characteristics. The troughs showed the enhancements of many SOA markers (p < 0.05), which appeared to be related to the high relative humidity. The diurnal patterns of 2-methyltetrols varied in differed cases, and their aqueous formation at night seemed plausible, particularly in the presence of troughs. Eight sources were identified for the organic matter in submicron PM (PM1-OM). Despite being an urban site, the mean SOA contribution (66.1 ± 10.5 %), primarily anthropogenic, was significant. Anthropogenic SOA dominated in the cases with continental and coastal air and in the early afternoon. Local cooking and vehicle emissions became predominant in the case of marine air without troughs. Even averaged over the study period in this summer month with the prevalence of marine air, primary cooking emissions contributed up to 44.2 % to PM1-OM in the early evening. The study highlighted the need to control regional anthropogenic SOA and local cooking emissions to mitigate PM pollution in HK.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"25 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141430367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-20DOI: 10.5194/egusphere-2024-1793
Norbert Glatthor, Gabriele P. Stiller, Thomas von Clarmann, Bernd Funke, Sylvia Kellmann, Andrea Linden
Abstract. We present a global climatology of upper tropospheric hydrogen cyanide (HCN), carbon monoxide (CO), acetylene (C2H2), ethane (C2H6), peroxyacetyl nitrate (PAN) and formic acid (HCOOH), obtained from MIPAS/Envisat observations between 2002 and 2012. At northern mid- and high latitudes the biomass burning tracer HCN as well as CO, PAN and HCOOH exhibit maxima during spring and/or summer and minima during winter. On the contrary, maximum northern extra-tropical C2H2 and C2H6 amounts were measured during winter and spring and minimum values during summer and fall. In the tropics and subtropics, enhanced amounts of all pollutants were observed during all seasons, especially widespread and up to southern mid-latitudes during austral spring. Other characteristic features are eastward transport of anthropogenic C2H6 and of biogenic HCOOH from Central and North America in boreal summer, accumulation of pollutants in the Asian Monsoon Anticyclone and enhanced C2H2 over South-East Asia in boreal winter. Clear indication of biogenic release of HCOOH was also found above tropical South America and Africa. A global correlation analysis of the other pollutants with HCN corroborates common release by biomass burning as source of the widespread southern hemispheric pollution during austral spring. Further, high correlation with HCN points to biomass burning as major source of tropical and subtropical C2H2 and PAN during most of the year. In the northern extra-tropics there are generally low correlations with HCN during spring and early summer, indicating the influence of anthropogenic and biogenic sources. However, in August there are stronger correlations above Siberia and boreal North America, which points to common release by boreal fires. This is confirmed by the respective enhancement ratios (ERs). The ERs measured above North-East Africa fit well to the emission ratios of the dominant local fire type (savanna burning) for C2H2, while those for CO, C2H6 and HCOOH rather indicate tropical forest fires or additional anthropogenic or biogenic sources. The southern hemispheric ΔC2H6/ΔHCN ERs obtained during August to October are in good agreement with the emission ratio for savanna fires. The same applies for ΔC2H2/ΔHCN in August and for ΔHCN/ΔCO as well as for ΔHCOOH/ΔHCN in October.
{"title":"Upper tropospheric pollutants observed by MIPAS: geographic and seasonal variations","authors":"Norbert Glatthor, Gabriele P. Stiller, Thomas von Clarmann, Bernd Funke, Sylvia Kellmann, Andrea Linden","doi":"10.5194/egusphere-2024-1793","DOIUrl":"https://doi.org/10.5194/egusphere-2024-1793","url":null,"abstract":"<strong>Abstract.</strong> We present a global climatology of upper tropospheric hydrogen cyanide (HCN), carbon monoxide (CO), acetylene (C<sub>2</sub>H<sub>2</sub>), ethane (C<sub>2</sub>H<sub>6</sub>), peroxyacetyl nitrate (PAN) and formic acid (HCOOH), obtained from MIPAS/Envisat observations between 2002 and 2012. At northern mid- and high latitudes the biomass burning tracer HCN as well as CO, PAN and HCOOH exhibit maxima during spring and/or summer and minima during winter. On the contrary, maximum northern extra-tropical C<sub>2</sub>H<sub>2</sub> and C<sub>2</sub>H<sub>6</sub> amounts were measured during winter and spring and minimum values during summer and fall. In the tropics and subtropics, enhanced amounts of all pollutants were observed during all seasons, especially widespread and up to southern mid-latitudes during austral spring. Other characteristic features are eastward transport of anthropogenic C<sub>2</sub>H<sub>6</sub> and of biogenic HCOOH from Central and North America in boreal summer, accumulation of pollutants in the Asian Monsoon Anticyclone and enhanced C<sub>2</sub>H<sub>2</sub> over South-East Asia in boreal winter. Clear indication of biogenic release of HCOOH was also found above tropical South America and Africa. A global correlation analysis of the other pollutants with HCN corroborates common release by biomass burning as source of the widespread southern hemispheric pollution during austral spring. Further, high correlation with HCN points to biomass burning as major source of tropical and subtropical C<sub>2</sub>H<sub>2</sub> and PAN during most of the year. In the northern extra-tropics there are generally low correlations with HCN during spring and early summer, indicating the influence of anthropogenic and biogenic sources. However, in August there are stronger correlations above Siberia and boreal North America, which points to common release by boreal fires. This is confirmed by the respective enhancement ratios (ERs). The ERs measured above North-East Africa fit well to the emission ratios of the dominant local fire type (savanna burning) for C<sub>2</sub>H<sub>2</sub>, while those for CO, C<sub>2</sub>H<sub>6</sub> and HCOOH rather indicate tropical forest fires or additional anthropogenic or biogenic sources. The southern hemispheric ΔC<sub>2</sub>H<sub>6</sub>/ΔHCN ERs obtained during August to October are in good agreement with the emission ratio for savanna fires. The same applies for ΔC<sub>2</sub>H<sub>2</sub>/ΔHCN in August and for ΔHCN/ΔCO as well as for ΔHCOOH/ΔHCN in October.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"12 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141430556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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