Pub Date : 2024-07-09DOI: 10.5194/acp-24-7699-2024
Yao Ge, Sverre Solberg, Mathew R. Heal, Stefan Reimann, Willem van Caspel, Bryan Hellack, Thérèse Salameh, David Simpson
Abstract. Atmospheric volatile organic compounds (VOCs) constitute a wide range of species, acting as precursors to ozone and aerosol formation. Atmospheric chemistry and transport models (CTMs) are crucial to understanding the emissions, distribution, and impacts of VOCs. Given the uncertainties in VOC emissions, lack of evaluation studies, and recent changes in emissions, this work adapts the European Monitoring and Evaluation Programme Meteorological Synthesizing Centre – West (EMEP MSC-W) CTM to evaluate emission inventories in Europe. Here we undertake the first intensive model–measurement comparison of VOCs in 2 decades. The modelled surface concentrations are evaluated both spatially and temporally, using measurements from the regular EMEP monitoring network in 2018 and 2019, as well as a 2022 campaign. To achieve this, we utilised the UK National Atmospheric Emissions Inventory to derive explicit emission profiles for individual species and employed a tracer method to produce pure concentrations that are directly comparable to observations. The degree to which the modelled and measured VOCs agree varies depending on the specific species. The model successfully captures the overall spatial and temporal variations of major alkanes (e.g. ethane, n-butane) and unsaturated species (e.g. ethene, benzene) but less so for propane, i-butane, and ethyne. This discrepancy underscores potential issues in the boundary conditions for the latter species and in their primary emissions from, in particular, the solvent and road transport sectors. Specifically, potential missing propane emissions and issues with its boundary conditions are highlighted by large model underestimations and smaller propane-to-ethane ratios compared to the measurement. Meanwhile, both the model and measurements show strong linear correlations among butane isomers and among pentane isomers, indicating common sources for these pairs of isomers. However, modelled ratios of i-butane to n-butane and i-pentane to n-pentane are approximately one-third of the measured ratios, which is largely driven by significant emissions of n-butane and n-pentane from the solvent sector. This suggests issues with the speciation profile of the solvent sector, underrepresented contributions from transport and fuel evaporation sectors in current inventories, or both. Furthermore, the modelled ethene-to-ethyne and benzene-to-ethyne ratios differ significantly from measured ratios. The different model performance strongly points to shortcomings in the spatial and temporal patterns and magnitudes of ethyne emissions, especially during winter. For OVOCs, the modelled and measured concentrations of methanal and methylglyoxal show a good agreement, despite a moderate underestimation by the model in summer. This discrepancy could be attributed to an underestimation of contributions from biogenic sources or possibly a model overestimation of their photolytic loss in summer. However, the insufficiency of suitabl
{"title":"Evaluation of modelled versus observed non-methane volatile organic compounds at European Monitoring and Evaluation Programme sites in Europe","authors":"Yao Ge, Sverre Solberg, Mathew R. Heal, Stefan Reimann, Willem van Caspel, Bryan Hellack, Thérèse Salameh, David Simpson","doi":"10.5194/acp-24-7699-2024","DOIUrl":"https://doi.org/10.5194/acp-24-7699-2024","url":null,"abstract":"Abstract. Atmospheric volatile organic compounds (VOCs) constitute a wide range of species, acting as precursors to ozone and aerosol formation. Atmospheric chemistry and transport models (CTMs) are crucial to understanding the emissions, distribution, and impacts of VOCs. Given the uncertainties in VOC emissions, lack of evaluation studies, and recent changes in emissions, this work adapts the European Monitoring and Evaluation Programme Meteorological Synthesizing Centre – West (EMEP MSC-W) CTM to evaluate emission inventories in Europe. Here we undertake the first intensive model–measurement comparison of VOCs in 2 decades. The modelled surface concentrations are evaluated both spatially and temporally, using measurements from the regular EMEP monitoring network in 2018 and 2019, as well as a 2022 campaign. To achieve this, we utilised the UK National Atmospheric Emissions Inventory to derive explicit emission profiles for individual species and employed a tracer method to produce pure concentrations that are directly comparable to observations. The degree to which the modelled and measured VOCs agree varies depending on the specific species. The model successfully captures the overall spatial and temporal variations of major alkanes (e.g. ethane, n-butane) and unsaturated species (e.g. ethene, benzene) but less so for propane, i-butane, and ethyne. This discrepancy underscores potential issues in the boundary conditions for the latter species and in their primary emissions from, in particular, the solvent and road transport sectors. Specifically, potential missing propane emissions and issues with its boundary conditions are highlighted by large model underestimations and smaller propane-to-ethane ratios compared to the measurement. Meanwhile, both the model and measurements show strong linear correlations among butane isomers and among pentane isomers, indicating common sources for these pairs of isomers. However, modelled ratios of i-butane to n-butane and i-pentane to n-pentane are approximately one-third of the measured ratios, which is largely driven by significant emissions of n-butane and n-pentane from the solvent sector. This suggests issues with the speciation profile of the solvent sector, underrepresented contributions from transport and fuel evaporation sectors in current inventories, or both. Furthermore, the modelled ethene-to-ethyne and benzene-to-ethyne ratios differ significantly from measured ratios. The different model performance strongly points to shortcomings in the spatial and temporal patterns and magnitudes of ethyne emissions, especially during winter. For OVOCs, the modelled and measured concentrations of methanal and methylglyoxal show a good agreement, despite a moderate underestimation by the model in summer. This discrepancy could be attributed to an underestimation of contributions from biogenic sources or possibly a model overestimation of their photolytic loss in summer. However, the insufficiency of suitabl","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"1 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141561308","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 : 2024-07-09DOI: 10.5194/egusphere-2024-1946
Duncan Watson-Parris, Laura J. Wilcox, Camilla W. Stjern, Robert J. Allen, Geeta Persad, Massimo A. Bollasina, Annica M. L. Ekman, Carley E. Iles, Manoj Joshi, Marianne T. Lund, Daniel McCoy, Daniel Westervelt, Andrew Williams, Bjørn H. Samset
Abstract. In 2020 the International Maritime Organization (IMO) implemented strict new regulations on the emissions of sulphate aerosol from the world's shipping fleet. This can be expected to lead to a reduction in aerosol-driven cooling, unmasking a portion of greenhouse gas warming. The magnitude of the effect is uncertain, however, due to the large remaining uncertainties in the climate response to aerosols. Here, we investigate this question using an 18-member ensemble of fully coupled climate simulations evenly sampling key modes of climate variability with the NCAR CESM2 model. We show that while there is a clear physical response of the climate system to the IMO regulations, including a surface temperature increase, we do not find global mean temperature influence that is significantly different from zero. The 20-year average global mean warming for 2020–2040 is +0.03 °C, with a 5–95 % confidence range of [-0.09, 0.19], reflecting the weakness of the perturbation relative to internal variability. We do, however, find a robust, non-zero regional temperature response in part of the North Atlantic. We also find that the maximum annual-mean ensemble-mean warming occurs around a decade after the perturbation in 2029, which means that the IMO regulations have likely had very limited influence on observed global warming to date. We further discuss our results in light of other, recent publications that have reached different conclusions. Overall, while the IMO regulations may contribute up to at 0.16 °C [-0.17, 0.52] to the global mean surface temperature in individual years during this decade, consistent with some early studies, such a response is unlikely to have been discernible above internal variability by the end of 2023 and is in fact consistent with zero throughout the 2020–2040 period.
{"title":"Weak surface temperature effects of recent reductions in shipping SO2 emissions, with quantification confounded by internal variability","authors":"Duncan Watson-Parris, Laura J. Wilcox, Camilla W. Stjern, Robert J. Allen, Geeta Persad, Massimo A. Bollasina, Annica M. L. Ekman, Carley E. Iles, Manoj Joshi, Marianne T. Lund, Daniel McCoy, Daniel Westervelt, Andrew Williams, Bjørn H. Samset","doi":"10.5194/egusphere-2024-1946","DOIUrl":"https://doi.org/10.5194/egusphere-2024-1946","url":null,"abstract":"<strong>Abstract.</strong> In 2020 the International Maritime Organization (IMO) implemented strict new regulations on the emissions of sulphate aerosol from the world's shipping fleet. This can be expected to lead to a reduction in aerosol-driven cooling, unmasking a portion of greenhouse gas warming. The magnitude of the effect is uncertain, however, due to the large remaining uncertainties in the climate response to aerosols. Here, we investigate this question using an 18-member ensemble of fully coupled climate simulations evenly sampling key modes of climate variability with the NCAR CESM2 model. We show that while there is a clear physical response of the climate system to the IMO regulations, including a surface temperature increase, we do not find global mean temperature influence that is significantly different from zero. The 20-year average global mean warming for 2020–2040 is +0.03 °C, with a 5–95 % confidence range of [-0.09, 0.19], reflecting the weakness of the perturbation relative to internal variability. We do, however, find a robust, non-zero regional temperature response in part of the North Atlantic. We also find that the maximum annual-mean ensemble-mean warming occurs around a decade after the perturbation in 2029, which means that the IMO regulations have likely had very limited influence on observed global warming to date. We further discuss our results in light of other, recent publications that have reached different conclusions. Overall, while the IMO regulations may contribute up to at 0.16 °C [-0.17, 0.52] to the global mean surface temperature in individual years during this decade, consistent with some early studies, such a response is unlikely to have been discernible above internal variability by the end of 2023 and is in fact consistent with zero throughout the 2020–2040 period.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"6 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141561309","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. Water-insoluble organic carbon (WIOC) constitutes a substantial portion of organic carbon (OC) and contributes significantly to light absorption by brown carbon (BrC), playing pivotal roles in climate forcing. China is a hotspot region with high levels of OC and BrC, but information regarding the sources and light-absorbing properties of WIOC on a national scale remains scarce. Here, we investigated the light-absorbing properties and sources of WIOC in 10 representative urban cities in China. On average, WIOC made up 33.4 ± 7.66 % and 40.5 ± 9.73 % of concentrations and light absorption at 365 nm (Abs365) of extractable OC (EX-OC), which includes relatively hydrophobic OC (WIOC and humic-like substances, HULIS-C) and hydrophilic OC (non-humic-like substances, non-HULIS-C). The mass absorption efficiency of WIOC at 365 nm (MAE365) was (1.59 ± 0.55 m2 (g C)−1) comparable to that of HULIS (1.54 ± 0.57 m2 (g C)−1) but significantly higher than non-HULIS (0.71 ± 0.28 m2 (g C)−1), indicating that hydrophobic OC possesses a stronger light-absorbing capacity than hydrophilic OC. Biomass burning (31.0 %) and coal combustion (31.1 %) were the dominant sources of WIOC, with coal combustion sources exhibiting the strongest light-absorbing capacity. Moreover, employing the simple forcing efficiency (SFE300–700 nm) method, we observed that WIOC exhibited the highest SFE300–700 nm (6.57 ± 5.37 W g−1) among the EX-OC fractions. The radiative forcing of EX-OC was predominantly contributed by hydrophobic OC (WIOC – 39.4 ± 15.5 % and HULIS – 39.5 ± 12.1 %). Considering the aromaticity, sources, and atmospheric processes of different carbonaceous components, we propose a light-absorbing carbonaceous continuum, revealing that components enriched with fossil sources tend to possess stronger light-absorbing capacity, higher aromatic levels, increased molecular weights, and greater recalcitrance in the atmosphere. Reducing fossil fuel emissions emerges as an effective means of mitigating both gaseous (CO2) and particulate light-absorbing carbonaceous warming components.
{"title":"The water-insoluble organic carbon in PM2.5 of typical Chinese urban areas: light-absorbing properties, potential sources, radiative forcing effects, and a possible light-absorbing continuum","authors":"Yangzhi Mo, Jun Li, Guangcai Zhong, Sanyuan Zhu, Shizhen Zhao, Jiao Tang, Hongxing Jiang, Zhineng Cheng, Chongguo Tian, Yingjun Chen, Gan Zhang","doi":"10.5194/acp-24-7755-2024","DOIUrl":"https://doi.org/10.5194/acp-24-7755-2024","url":null,"abstract":"Abstract. Water-insoluble organic carbon (WIOC) constitutes a substantial portion of organic carbon (OC) and contributes significantly to light absorption by brown carbon (BrC), playing pivotal roles in climate forcing. China is a hotspot region with high levels of OC and BrC, but information regarding the sources and light-absorbing properties of WIOC on a national scale remains scarce. Here, we investigated the light-absorbing properties and sources of WIOC in 10 representative urban cities in China. On average, WIOC made up 33.4 ± 7.66 % and 40.5 ± 9.73 % of concentrations and light absorption at 365 nm (Abs365) of extractable OC (EX-OC), which includes relatively hydrophobic OC (WIOC and humic-like substances, HULIS-C) and hydrophilic OC (non-humic-like substances, non-HULIS-C). The mass absorption efficiency of WIOC at 365 nm (MAE365) was (1.59 ± 0.55 m2 (g C)−1) comparable to that of HULIS (1.54 ± 0.57 m2 (g C)−1) but significantly higher than non-HULIS (0.71 ± 0.28 m2 (g C)−1), indicating that hydrophobic OC possesses a stronger light-absorbing capacity than hydrophilic OC. Biomass burning (31.0 %) and coal combustion (31.1 %) were the dominant sources of WIOC, with coal combustion sources exhibiting the strongest light-absorbing capacity. Moreover, employing the simple forcing efficiency (SFE300–700 nm) method, we observed that WIOC exhibited the highest SFE300–700 nm (6.57 ± 5.37 W g−1) among the EX-OC fractions. The radiative forcing of EX-OC was predominantly contributed by hydrophobic OC (WIOC – 39.4 ± 15.5 % and HULIS – 39.5 ± 12.1 %). Considering the aromaticity, sources, and atmospheric processes of different carbonaceous components, we propose a light-absorbing carbonaceous continuum, revealing that components enriched with fossil sources tend to possess stronger light-absorbing capacity, higher aromatic levels, increased molecular weights, and greater recalcitrance in the atmosphere. Reducing fossil fuel emissions emerges as an effective means of mitigating both gaseous (CO2) and particulate light-absorbing carbonaceous warming components.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"2015 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141561306","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 : 2024-07-09DOI: 10.5194/egusphere-2024-1982
Prosper K. Nyassor, Cristiano M. Wrasse, Igo Paulino, Cosme A. O. B. Figueiredo, Ricardo A. Buriti, Hisao Takahashi, Delano Gobbi, Gabriel A. Giongo
Abstract. Simultaneous observations of airglow intensity, rotational temperature, and wind data at São João do Cariri (36.31° W; 07.40° S) by Co-located photometer, all-sky imager, and meteor radar were used to study the characteristics of vertical propagating gravity waves (GWs). Using the photometer data, the phase progression of GWs with the same propagation period in the OI 557.7nm, O2, NaD-line, and OH (6-2) emission layers were then used to determine the upward or downward vertical propagation of the waves. The vertical phase speed and wavelength are estimated using the wave period and phase difference at different altitude. From the O2 and OH (6-2) rotational temperatures, the total energy and the momentum flux of the downward propagating GWs were determined. For the upward propagating GW only the momentum flux and potential energy were estimated due to lack of observed wind. Further analysis of the momentum flux for each of the two events revealed that the momentum flux and potential energy of the downward propagating GWs increases with decreasing altitude. On the contrary, the GW momentum and energy of the upward propagating waves increases with increasing altitude. Thus, clearly demonstrating the transfer of momentum flux and energy from the source to the sink. This characteristic difference can be used to careful analysis the changes in GWs energy propagation due to reflection of non-primary GWs.
摘要利用共址光度计、全天空成像仪和流星雷达在 São João do Cariri（西经 36.31 度；南纬 07.40 度）同时观测到的气辉强度、旋转温度和风数据，研究了垂直传播重力波（GWs）的特征。利用光度计数据，在 OI 557.7nm、O2、NaD 线和 OH（6-2）发射层中对具有相同传播周期的重力波的相位变化进行分析，以确定重力波是向上还是向下垂直传播。利用不同高度的波周期和相位差估算垂直相速和波长。根据 O2 和 OH (6-2) 旋转温度，确定了向下传播的全球大气环流的总能量和动量通量。对于向上传播的全球大气环流，由于没有观测到风，只估算了动量通量和势能。对两个事件的动量通量的进一步分析表明，向下传播的全球大气风暴的动量通量和势能随着高度的降低而增加。相反，向上传播的全球定位系统的动量和能量则随着高度的增加而增加。因此，这清楚地表明了动量通量和能量从源向汇的转移。可以利用这一特征差异来仔细分析非初级全球定位系统反射导致的全球定位系统能量传播的变化。
{"title":"Momentum flux characteristics of vertical propagating Gravity Waves","authors":"Prosper K. Nyassor, Cristiano M. Wrasse, Igo Paulino, Cosme A. O. B. Figueiredo, Ricardo A. Buriti, Hisao Takahashi, Delano Gobbi, Gabriel A. Giongo","doi":"10.5194/egusphere-2024-1982","DOIUrl":"https://doi.org/10.5194/egusphere-2024-1982","url":null,"abstract":"<strong>Abstract.</strong> Simultaneous observations of airglow intensity, rotational temperature, and wind data at São João do Cariri (36.31° W; 07.40° S) by Co-located photometer, all-sky imager, and meteor radar were used to study the characteristics of vertical propagating gravity waves (GWs). Using the photometer data, the phase progression of GWs with the same propagation period in the OI 557.7nm, O<sub>2</sub>, NaD-line, and OH (6-2) emission layers were then used to determine the upward or downward vertical propagation of the waves. The vertical phase speed and wavelength are estimated using the wave period and phase difference at different altitude. From the O<sub>2</sub> and OH (6-2) rotational temperatures, the total energy and the momentum flux of the downward propagating GWs were determined. For the upward propagating GW only the momentum flux and potential energy were estimated due to lack of observed wind. Further analysis of the momentum flux for each of the two events revealed that the momentum flux and potential energy of the downward propagating GWs increases with decreasing altitude. On the contrary, the GW momentum and energy of the upward propagating waves increases with increasing altitude. Thus, clearly demonstrating the transfer of momentum flux and energy from the source to the sink. This characteristic difference can be used to careful analysis the changes in GWs energy propagation due to reflection of non-primary GWs.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"31 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141561310","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 : 2024-07-09DOI: 10.5194/acp-24-7731-2024
Jiao Xue, Tian Zhang, Keyhong Park, Jinpei Yan, Young Jun Yoon, Jiyeon Park, Bingbing Wang
Abstract. Atmospheric particles can impact cloud formation and play a critical role in regulating cloud properties. However, particle characteristics at the single-particle level and their ability to act as ice-nucleating particles (INPs) over the marine atmosphere are poorly understood. In this study, we present micro-spectroscopic characterizations and ice nucleation properties of particles collected during a cruise from South Korea to Antarctica in 2019. Most of the samples were dominated by fresh sea salt, aged sea salt, and sea salt mixed with sulfate particles, with total number percentages ranging from 48 % to 99 % over the western Pacific and the Southern Ocean. The mixing-state index of the particle population ranged from 50 % to 95 % over the Northern Hemisphere and Southern Hemisphere. Multiphase processes on sea salt particles resulted in chlorine deficiency. This selective aging process made the marine particle population more externally mixed. Ice nucleation onset conditions primarily for the deposition mode were measured and the investigated particles showed diverse ice nucleation abilities. The fresh sea salt particles with organic coatings exhibited the highest ice nucleation ability at a relative humidity with respect to ice as low as 121 %. The sea salt mixed sulfate particle was enriched in INPs by a factor of 1.9. Aging processes affected both the mixing state of the particles and their ice nucleation abilities. Our analysis shows that assuming an internally mixed particle population in the marine atmosphere can lead to errors of several orders of magnitude in predicting ice nucleation rates.
{"title":"Diverse sources and aging change the mixing state and ice nucleation properties of aerosol particles over the western Pacific and Southern Ocean","authors":"Jiao Xue, Tian Zhang, Keyhong Park, Jinpei Yan, Young Jun Yoon, Jiyeon Park, Bingbing Wang","doi":"10.5194/acp-24-7731-2024","DOIUrl":"https://doi.org/10.5194/acp-24-7731-2024","url":null,"abstract":"Abstract. Atmospheric particles can impact cloud formation and play a critical role in regulating cloud properties. However, particle characteristics at the single-particle level and their ability to act as ice-nucleating particles (INPs) over the marine atmosphere are poorly understood. In this study, we present micro-spectroscopic characterizations and ice nucleation properties of particles collected during a cruise from South Korea to Antarctica in 2019. Most of the samples were dominated by fresh sea salt, aged sea salt, and sea salt mixed with sulfate particles, with total number percentages ranging from 48 % to 99 % over the western Pacific and the Southern Ocean. The mixing-state index of the particle population ranged from 50 % to 95 % over the Northern Hemisphere and Southern Hemisphere. Multiphase processes on sea salt particles resulted in chlorine deficiency. This selective aging process made the marine particle population more externally mixed. Ice nucleation onset conditions primarily for the deposition mode were measured and the investigated particles showed diverse ice nucleation abilities. The fresh sea salt particles with organic coatings exhibited the highest ice nucleation ability at a relative humidity with respect to ice as low as 121 %. The sea salt mixed sulfate particle was enriched in INPs by a factor of 1.9. Aging processes affected both the mixing state of the particles and their ice nucleation abilities. Our analysis shows that assuming an internally mixed particle population in the marine atmosphere can lead to errors of several orders of magnitude in predicting ice nucleation rates.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"15 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141561304","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 : 2024-07-08DOI: 10.5194/egusphere-2024-1849
Srinivasan Prasanth, Narayana Sarma Anand, Kudilil Sunilkumar, Subin Jose, Kenath Arun, Sreedharan K. Satheesh, Krishnaswamy K. Moorthy
Abstract. Extreme bushfire events amplify climate change by emitting greenhouse gases and destroying carbon sinks while causing economic damage through property destruction and even fatalities. One such bushfire occurred in Australia during 2019/2020, injecting large amounts of aerosols and gases into the stratosphere and depleting the ozone layer. While previous studies focused on the drivers behind ozone depletion, the bushfire impact on the polar stratospheric clouds (PSC), a paramount factor in ozone depletion, has not been extensively investigated so far. This study focuses on the effects of bushfire aerosols on the dynamics and stratospheric chemistry related to PSC formation and its pathways. An analysis from Aura's microwave limb sounder revealed enhanced hydrolysis of dinitrogen pentoxide significantly increased nitric acid (HNO3) in the high-latitude lower stratosphere in early 2020. Using a novel methodology which retrieves formation pathways of PSCs from spaceborne lidar observations, we found that the enhanced HNO3 condensed on bushfire aerosols, forming 82 % of Liquid Nitric Acid Trihydrate (LNAT), which rapidly converted to 77 % of ice, resulting in an anomalous high areal coverage of ice PSCs. This highlights the primary formation pathways of ice and LNAT and possibly helps us to simulate the PSC formation and denitrification process better in climate models. As tropospheric warming is anticipated to increase the frequency of extreme wildfire events and stratospheric cooling is expected to expand the PSC areal coverage, these findings will contribute significantly to a deeper understanding of the impacts of extreme wildfire events on stratospheric chemistry and PSC dynamics.
{"title":"Australian Bushfire Emissions Result in Enhanced Polar Stratospheric Ice Clouds","authors":"Srinivasan Prasanth, Narayana Sarma Anand, Kudilil Sunilkumar, Subin Jose, Kenath Arun, Sreedharan K. Satheesh, Krishnaswamy K. Moorthy","doi":"10.5194/egusphere-2024-1849","DOIUrl":"https://doi.org/10.5194/egusphere-2024-1849","url":null,"abstract":"<strong>Abstract.</strong> Extreme bushfire events amplify climate change by emitting greenhouse gases and destroying carbon sinks while causing economic damage through property destruction and even fatalities. One such bushfire occurred in Australia during 2019/2020, injecting large amounts of aerosols and gases into the stratosphere and depleting the ozone layer. While previous studies focused on the drivers behind ozone depletion, the bushfire impact on the polar stratospheric clouds (PSC), a paramount factor in ozone depletion, has not been extensively investigated so far. This study focuses on the effects of bushfire aerosols on the dynamics and stratospheric chemistry related to PSC formation and its pathways. An analysis from Aura's microwave limb sounder revealed enhanced hydrolysis of dinitrogen pentoxide significantly increased nitric acid (HNO<sub>3</sub>) in the high-latitude lower stratosphere in early 2020. Using a novel methodology which retrieves formation pathways of PSCs from spaceborne lidar observations, we found that the enhanced HNO<sub>3</sub> condensed on bushfire aerosols, forming 82 % of Liquid Nitric Acid Trihydrate (LNAT), which rapidly converted to 77 % of ice, resulting in an anomalous high areal coverage of ice PSCs. This highlights the primary formation pathways of ice and LNAT and possibly helps us to simulate the PSC formation and denitrification process better in climate models. As tropospheric warming is anticipated to increase the frequency of extreme wildfire events and stratospheric cooling is expected to expand the PSC areal coverage, these findings will contribute significantly to a deeper understanding of the impacts of extreme wildfire events on stratospheric chemistry and PSC dynamics.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"140 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141557204","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 : 2024-07-08DOI: 10.5194/egusphere-2024-1821
Irina Petropavlovskikh, Jeannette D. Wild, Kari Abromitis, Peter Effertz, Koji Miyagawa, Lawrence E. Flynn, Eliane Maillard-Barra, Robert Damadeo, Glen McConville, Bryan Johnson, Patrick Cullis, Sophie Godin-Beekmann, Gerald Ancellet, Richard Querel, Roeland Van Malderen, Daniel Zawada
Abstract. This study presents an updated evaluation of stratospheric ozone profile trends at Arosa/Davos/Hohenpeißenberg, Switzerland/Germany, Observatory de Haute Provence (OHP), France, Boulder, Colorado, Mauna Loa Observatory (MLO) and Hilo, Hawaii, and Lauder, New Zealand with focus on the ozone recovery period post 2000. Trends are derived using vertical ozone profiles from NOAA’s Dobson Network via the Umkehr method (with a recent new homogenization), ozonesondes, and the NOAA COHesive SBUV/OMPS satellite-based record (COH) sampled to match geographical coordinates of the ground-based stations used in this study. Analyses of long-term changes in stratospheric ozone time series were performed using the updated version (0.8.0) of the Long-term Ozone Trends and Uncertainties in the Stratosphere (LOTUS) Independent Linear Trend (ILT) regression model. This study finds a consistency of the trends derived from the different observational records, which is a key factor to the understanding of the recovery of the ozone layer after the implementation of the Montreal Protocol and its amendments that control ozone-depleting substances production and release into the atmosphere. The Northern Hemispheric Umkehr records of Aros/Davos, OHP, and MLO all show positive trends in the mid to upper stratosphere with trends peaking at ~+2 %/decade. Although the upper stratospheric ozone trends derived from COH satellite records are more positive than those detected by the Umkehr system, the agreement is within the two sigma uncertainty. Umkehr trends in the upper stratosphere at Boulder and Lauder are positive but not statistically significant, while COH trends are larger and statistically significant (within 2 sigma). In the lower stratosphere, trends derived from Umkehr and ozonesonde records are mostly negative (except for positive ozonesonde trends at OHP), however the uncertainties are quite large. Additional dynamical proxies were investigated in the LOTUS model at five ground-based sites. The use of additional proxies did not significantly change trends, but equivalent latitude reduced the uncertainty of the Umkehr and COH trends in the upper stratosphere and at higher latitudes. In lower layers, additional predictors (tropopause pressure for all stations, two extra components of Quasi-Biennial Oscillation at MLO, Arctic Oscillation at Arosa/Davos, OHP and MLO) improve the model fit and reduce trend uncertainties as seen by Umkehr and sonde.
{"title":"Ozone trends in homogenized Umkehr, Ozonesonde, and COH overpass records","authors":"Irina Petropavlovskikh, Jeannette D. Wild, Kari Abromitis, Peter Effertz, Koji Miyagawa, Lawrence E. Flynn, Eliane Maillard-Barra, Robert Damadeo, Glen McConville, Bryan Johnson, Patrick Cullis, Sophie Godin-Beekmann, Gerald Ancellet, Richard Querel, Roeland Van Malderen, Daniel Zawada","doi":"10.5194/egusphere-2024-1821","DOIUrl":"https://doi.org/10.5194/egusphere-2024-1821","url":null,"abstract":"<strong>Abstract.</strong> This study presents an updated evaluation of stratospheric ozone profile trends at Arosa/Davos/Hohenpeißenberg, Switzerland/Germany, Observatory de Haute Provence (OHP), France, Boulder, Colorado, Mauna Loa Observatory (MLO) and Hilo, Hawaii, and Lauder, New Zealand with focus on the ozone recovery period post 2000. Trends are derived using vertical ozone profiles from NOAA’s Dobson Network via the Umkehr method (with a recent new homogenization), ozonesondes, and the NOAA COHesive SBUV/OMPS satellite-based record (COH) sampled to match geographical coordinates of the ground-based stations used in this study. Analyses of long-term changes in stratospheric ozone time series were performed using the updated version (0.8.0) of the Long-term Ozone Trends and Uncertainties in the Stratosphere (LOTUS) Independent Linear Trend (ILT) regression model. This study finds a consistency of the trends derived from the different observational records, which is a key factor to the understanding of the recovery of the ozone layer after the implementation of the Montreal Protocol and its amendments that control ozone-depleting substances production and release into the atmosphere. The Northern Hemispheric Umkehr records of Aros/Davos, OHP, and MLO all show positive trends in the mid to upper stratosphere with trends peaking at ~+2 %/decade. Although the upper stratospheric ozone trends derived from COH satellite records are more positive than those detected by the Umkehr system, the agreement is within the two sigma uncertainty. Umkehr trends in the upper stratosphere at Boulder and Lauder are positive but not statistically significant, while COH trends are larger and statistically significant (within 2 sigma). In the lower stratosphere, trends derived from Umkehr and ozonesonde records are mostly negative (except for positive ozonesonde trends at OHP), however the uncertainties are quite large. Additional dynamical proxies were investigated in the LOTUS model at five ground-based sites. The use of additional proxies did not significantly change trends, but equivalent latitude reduced the uncertainty of the Umkehr and COH trends in the upper stratosphere and at higher latitudes. In lower layers, additional predictors (tropopause pressure for all stations, two extra components of Quasi-Biennial Oscillation at MLO, Arctic Oscillation at Arosa/Davos, OHP and MLO) improve the model fit and reduce trend uncertainties as seen by Umkehr and sonde.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"365 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141557203","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 : 2024-07-08DOI: 10.5194/egusphere-2024-2032
Mohammed Jaoui, Klara Nestorowicz, Krzysztof Rudzinski, Michael Lewandowski, Tadeusz Kleindienst, Julio Torres, Ewa Bulska, Witold Danikiewicz, Rafal Szmigielski
Abstract. This study investigated the effect of relative humidity (RH) on the chemical composition of gas and particle phases formed from the photooxidation of 1,3-butadiene (13BD) in the presence of NOx under acidic and non-acidic conditions. The experiments were conducted in a 14.5 m3 smog chamber operated in a steady-state mode. Products were identified by high performance liquid chromatography, gas chromatography mass spectrometry and ultrahigh performance liquid chromatography coupled with high resolution mass spectrometry. More than 48 oxygenated products were identified including 33 oxygenated organics, 10 organosulfates (OSs), PAN, APAN, glyoxal, formaldehyde, and acrolein. Secondary organic aerosol (SOA) mass and reaction products were found to be dependent on RH and acidity of the aerosol. SOA mass, and most SOA products (i) were higher under acidic than non-acidic conditions, and (ii) decreased with increasing RH. Glyceric acid, threitols, threonic acids, four dimers, three unknowns, and four organosulfates were among the main species measured either under acidic or non-acidic conditions across all RH levels. Total secondary organic carbon and carbon yield decreased with increasing RH under both acidic and non-acidic conditions. The photochemical reactivity of 13BD in our systems decreased with increasing RH and was faster under non-acidic than acidic conditions. To determine the contribution of 13BD products to ambient aerosol, we analyzed PM2.5 samples collected at three European monitoring stations located in Poland. The occurrence of several 13BD SOA products (e.g., glyceric acid, tartronic acid, threonic acid, tartaric acid, and OSs) in the field samples suggests that 13BD could contribute to ambient aerosol formation.
{"title":"Atmospheric oxidation of 1,3-butadiene: influence of acidity and relative humidity on SOA composition and air toxic compounds","authors":"Mohammed Jaoui, Klara Nestorowicz, Krzysztof Rudzinski, Michael Lewandowski, Tadeusz Kleindienst, Julio Torres, Ewa Bulska, Witold Danikiewicz, Rafal Szmigielski","doi":"10.5194/egusphere-2024-2032","DOIUrl":"https://doi.org/10.5194/egusphere-2024-2032","url":null,"abstract":"<strong>Abstract.</strong> This study investigated the effect of relative humidity (RH) on the chemical composition of gas and particle phases formed from the photooxidation of 1,3-butadiene (13BD) in the presence of NOx under acidic and non-acidic conditions. The experiments were conducted in a 14.5 m<sup>3</sup> smog chamber operated in a steady-state mode. Products were identified by high performance liquid chromatography, gas chromatography mass spectrometry and ultrahigh performance liquid chromatography coupled with high resolution mass spectrometry. More than 48 oxygenated products were identified including 33 oxygenated organics, 10 organosulfates (OSs), PAN, APAN, glyoxal, formaldehyde, and acrolein. Secondary organic aerosol (SOA) mass and reaction products were found to be dependent on RH and acidity of the aerosol. SOA mass, and most SOA products (i) were higher under acidic than non-acidic conditions, and (ii) decreased with increasing RH. Glyceric acid, threitols, threonic acids, four dimers, three unknowns, and four organosulfates were among the main species measured either under acidic or non-acidic conditions across all RH levels. Total secondary organic carbon and carbon yield decreased with increasing RH under both acidic and non-acidic conditions. The photochemical reactivity of 13BD in our systems decreased with increasing RH and was faster under non-acidic than acidic conditions. To determine the contribution of 13BD products to ambient aerosol, we analyzed PM<sub>2.5</sub> samples collected at three European monitoring stations located in Poland. The occurrence of several 13BD SOA products (e.g., glyceric acid, tartronic acid, threonic acid, tartaric acid, and OSs) in the field samples suggests that 13BD could contribute to ambient aerosol formation.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"49 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141557207","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 : 2024-07-08DOI: 10.5194/egusphere-2024-1937
Shiv Priyam Raghuraman, Brian Soden, Amy Clement, Gabriel Vecchi, Sofia Menemenlis, Wenchang Yang
Abstract. Global-mean surface temperature rapidly increased 0.27 ± 0.05 K from 2022 to 2023. Such an interannual global warming spike is not unprecedented in the observational record with previous instances occurring in 1956–57 and 1976–77. However, why global warming spikes occur is unknown and the rapid global warming of 2023 has led to concerns that it could have been externally driven. Here we show that climate models that are subject only to internal variability can generate such spikes, but they are an uncommon occurrence (𝑝 = 2.6 ± 0.1 %). However, when a prolonged La Niña immediately precedes an El Niño in the simulations, as occurred in nature in 1956–57, 1976–77, 2022–23, such spikes become much more common (𝑝 = 16.5 ± 0.6 %). Furthermore, we find that nearly all simulated spikes (94 %) are associated with El Niño occurring that year. Thus, our results underscore the importance of El Niño/Southern Oscillation in driving the occurrence of global warming spikes such as the one in 2023, without needing to invoke anthropogenic forcing, such as changes in atmospheric concentrations of greenhouse gases or aerosols, as an explanation.
{"title":"The 2023 global warming spike was driven by El Niño/Southern Oscillation","authors":"Shiv Priyam Raghuraman, Brian Soden, Amy Clement, Gabriel Vecchi, Sofia Menemenlis, Wenchang Yang","doi":"10.5194/egusphere-2024-1937","DOIUrl":"https://doi.org/10.5194/egusphere-2024-1937","url":null,"abstract":"<strong>Abstract.</strong> Global-mean surface temperature rapidly increased 0.27 ± 0.05 K from 2022 to 2023. Such an interannual global warming spike is not unprecedented in the observational record with previous instances occurring in 1956–57 and 1976–77. However, why global warming spikes occur is unknown and the rapid global warming of 2023 has led to concerns that it could have been externally driven. Here we show that climate models that are subject only to internal variability can generate such spikes, but they are an uncommon occurrence (<span>𝑝</span> = 2.6 ± 0.1 %). However, when a prolonged La Niña immediately precedes an El Niño in the simulations, as occurred in nature in 1956–57, 1976–77, 2022–23, such spikes become much more common (<span>𝑝</span> = 16.5 ± 0.6 %). Furthermore, we find that nearly all simulated spikes (94 %) are associated with El Niño occurring that year. Thus, our results underscore the importance of El Niño/Southern Oscillation in driving the occurrence of global warming spikes such as the one in 2023, without needing to invoke anthropogenic forcing, such as changes in atmospheric concentrations of greenhouse gases or aerosols, as an explanation.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"25 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141557205","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 : 2024-07-08DOI: 10.5194/egusphere-2024-2020
Claudia Christine Stephan, Bjorn Stevens
Abstract. Tropical precipitation cluster area and intensity distributions follow power laws, but the physical processes responsible for this macroscopic behavior remain unknown.We analyze global simulations at ten-kilometer horizontal resolution that are configured to have drastically varying degrees of realism, ranging from global radiative-convective equilibrium to fully realistic atmospheric simulations, to investigate how dynamics influence precipitation statistics. We find the presence of stirring and large-scale vertical overturning, as associated with substantial planetary and synoptic-scale variability, to be key for having cluster statistics approach power laws. The presence of such large-scale dynamics is reflected in steep vertical velocity spectra. Large-scale rising and sinking modulate the column water vapor and temperature field, leading to a heterogeneous distribution of moist and dry patches and regions of strong mass flux, in which large precipitation clusters form. Our findings suggest that power laws in Earth’s precipitation cluster statistics stem from the robust power laws of atmospheric motions.
{"title":"Dynamical imprints on precipitation cluster statistics across a hierarchy of high-resolution simulations","authors":"Claudia Christine Stephan, Bjorn Stevens","doi":"10.5194/egusphere-2024-2020","DOIUrl":"https://doi.org/10.5194/egusphere-2024-2020","url":null,"abstract":"<strong>Abstract.</strong> Tropical precipitation cluster area and intensity distributions follow power laws, but the physical processes responsible for this macroscopic behavior remain unknown.We analyze global simulations at ten-kilometer horizontal resolution that are configured to have drastically varying degrees of realism, ranging from global radiative-convective equilibrium to fully realistic atmospheric simulations, to investigate how dynamics influence precipitation statistics. We find the presence of stirring and large-scale vertical overturning, as associated with substantial planetary and synoptic-scale variability, to be key for having cluster statistics approach power laws. The presence of such large-scale dynamics is reflected in steep vertical velocity spectra. Large-scale rising and sinking modulate the column water vapor and temperature field, leading to a heterogeneous distribution of moist and dry patches and regions of strong mass flux, in which large precipitation clusters form. Our findings suggest that power laws in Earth’s precipitation cluster statistics stem from the robust power laws of atmospheric motions.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"55 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141557206","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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