Abstract. Stable nitrogen isotopic composition (δ15N) has proven to be a valuable tool for identifying sources of nitrates (NO3–) in PM2.5. However, the absence of a systematic study on the δ15N values of domestic NOx sources hinders accurate identification of NO3– sources in China. Here, we systematically determined and refined δ15N values for six categories of NOx sources in the local Tianjin area using an active sampling method. Moreover, the δ15N values of NO3– in PM2.5 were measured during pre-heating, mid-heating and late-heating periods, which are the most heavily polluted in Tianjin. Results shown that the representative nature and region-specific characteristics of isotopic fingerprints for six categories of NOx sources in Tianjin. The Bayesian isotope mixing (MixSIAR) model demonstrated that coal combustion, biomass burning, and vehicle exhaust collectively contributed more than 60 %, dominating the sources of NO3– during sampling periods in Tianjin. However, failure to consider the isotopic signatures of local NOx sources could result in an underestimation of the contribution from coal combustion. Additionally, the absence of industrial sources, an uncharacterized source in previous studies, may directly result in the contribution fraction of other sources being overestimated by the model more than 15 %. Notably, as the number of sources input to the model increased, the contribution of various NOx sources was becoming more stable, and the inter-influence between various sources significantly reduced. This study demonstrated that the refined isotopic fingerprint in a region-specific context could more effectively distinguish source of NO3–, thereby providing valuable insights for controlling NO3– pollution.
{"title":"Technical note: Refining δ15N isotopic fingerprints of local NOx for accurate source identification of nitrate in PM2.5","authors":"Hao Xiao, Qinkai Li, Shiyuan Ding, Wenjing Dai, Gaoyang Cui, Xiaodong Li","doi":"10.5194/egusphere-2024-1621","DOIUrl":"https://doi.org/10.5194/egusphere-2024-1621","url":null,"abstract":"<strong>Abstract.</strong> Stable nitrogen isotopic composition (δ<sup>15</sup>N) has proven to be a valuable tool for identifying sources of nitrates (NO<sub>3</sub><sup>–</sup>) in PM<sub>2.5</sub>. However, the absence of a systematic study on the δ<sup>15</sup>N values of domestic NOx sources hinders accurate identification of NO<sub>3</sub><sup>–</sup> sources in China. Here, we systematically determined and refined δ<sup>15</sup>N values for six categories of NOx sources in the local Tianjin area using an active sampling method. Moreover, the δ<sup>15</sup>N values of NO<sub>3</sub><sup>–</sup> in PM<sub>2.5</sub> were measured during pre-heating, mid-heating and late-heating periods, which are the most heavily polluted in Tianjin. Results shown that the representative nature and region-specific characteristics of isotopic fingerprints for six categories of NOx sources in Tianjin. The Bayesian isotope mixing (MixSIAR) model demonstrated that coal combustion, biomass burning, and vehicle exhaust collectively contributed more than 60 %, dominating the sources of NO<sub>3</sub><sup>–</sup> during sampling periods in Tianjin. However, failure to consider the isotopic signatures of local NOx sources could result in an underestimation of the contribution from coal combustion. Additionally, the absence of industrial sources, an uncharacterized source in previous studies, may directly result in the contribution fraction of other sources being overestimated by the model more than 15 %. Notably, as the number of sources input to the model increased, the contribution of various NOx sources was becoming more stable, and the inter-influence between various sources significantly reduced. This study demonstrated that the refined isotopic fingerprint in a region-specific context could more effectively distinguish source of NO<sub>3</sub><sup>–</sup>, thereby providing valuable insights for controlling NO<sub>3</sub><sup>–</sup> pollution.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"131 10 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141462408","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 : 2024-06-27DOI: 10.5194/egusphere-2024-1891
Luís Filipe Escusa dos Santos, Hannah C. Frostenberg, Alejandro Baró Pérez, Annica M. L. Ekman, Luisa Ickes, Erik S. Thomson
<strong>Abstract.</strong> Increased surface warming over the Arctic, triggered by increased greenhouse gas concentrations and feedback processes in the climate system, has been causing a steady decline in sea-ice extent and thickness. With the retreating sea-ice, shipping activity will likely increase in the future driven by economic activity and the potential for realizing time and fuel savings from transiting shorter trade routes. Moreover, over the last decade, the global shipping sector has been subject to regulatory changes, that affect the physicochemical properties of exhaust particles. International regulations aiming to reduce SO<sub>x</sub> and particulate matter (PM) emissions, mandate ships to burn fuels with reduced sulfur content or alternatively, use wet scrubbing as exhaust after-treatment when using fuels with sulfur contents exceeding regulatory limits. Compliance measures affect the physicochemical properties of exhaust particles and their cloud condensation nuclei (CCN) activity in different ways, with the potential to have both direct and indirect impacts on atmospheric processes such as the formation and lifetime of clouds. Given the relatively pristine Arctic environment, ship exhaust particle emissions could be a large perturbation to natural baseline Arctic aerosol concentrations. Low-level stratiform mixed-phase clouds cover large areas of the Arctic region and play an important role in the regional energy budget. Results from laboratory marine engine measurements, which investigated the impact of fuel sulfur content (FSC) reduction and wet scrubbing on exhaust particle properties, motivate the use of large eddy simulations to further investigate how such particles may influence the micro- and macrophysical properties of a stratiform mixed-phase cloud case observed during the Arctic Summer Cloud Ocean Study campaign. Simulated enhancements of ship exhaust particles predominantly affected the liquid-phase properties of the cloud and led to a decrease in liquid surface precipitation, increased cloud albedo and increased longwave surface warming. The magnitude of the impact strongly depended on ship exhaust particle concentration, hygroscopicity, and size where the effect of particle size dominated the impact of hygroscopicity. While low FSC exhaust particles were mostly observed to affect cloud properties at exhaust particle concentrations of 1000 cm<sup>-3</sup>, exhaust wet scrubbing already led to significant changes at concentrations of 100 cm<sup>-3</sup>. Additional simulations with cloud ice water path increased from ≈5.5 g m<sup>-2</sup> to ≈9.3 g m<sup>-2</sup>, show more muted responses to ship exhaust perturbations but revealed that exhaust perturbations may even lead to a slight radiative cooling effect depending on the microphysical state of the cloud. The regional impact of shipping activity on Arctic cloud properties may, therefore, strongly depend on ship fuel type, whether ships utilize wet scrubbers, and
摘要由于温室气体浓度增加和气候系统中的反馈过程，北极地区地表变暖，导致海冰范围和厚度持续下降。随着海冰的消退，未来航运活动很可能会在经济活动的推动下增加，而且通过更短的贸易航线可以节省时间和燃料。此外，在过去的十年中，全球航运业一直受到法规变化的影响，从而影响到废气颗粒的物理化学特性。旨在减少硫氧化物和微粒物质（PM）排放的国际法规要求船舶燃烧硫含量较低的燃料，或者在使用硫含量超过法规限制的燃料时使用湿式洗涤作为尾气后处理。合规措施会以不同的方式影响废气颗粒的物理化学特性及其云凝结核 (CCN) 活性，有可能对云的形成和寿命等大气过程产生直接和间接影响。鉴于北极环境相对原始，船舶废气颗粒排放可能会对北极气溶胶的自然基线浓度造成巨大干扰。低层平流混合相云覆盖了北极地区的大片区域，在区域能量预算中发挥着重要作用。实验室船用发动机测量的结果研究了降低燃料硫含量（FSC）和湿式洗涤对废气颗粒特性的影响，这促使我们使用大涡模拟来进一步研究这些颗粒如何影响在北极夏季云海研究活动中观测到的平流混合相云的微观和宏观物理特性。模拟的船舶废气颗粒增强主要影响了云的液相特性，导致液面降水减少、云反照率增加和长波表面增温。影响的大小在很大程度上取决于船舶废气颗粒的浓度、吸湿性和大小，其中颗粒大小的影响在吸湿性的影响中占主导地位。虽然在废气颗粒浓度为 1000 cm-3 时，观察到低 FSC 废气颗粒对云特性的影响最大，但在浓度为 100 cm-3 时，废气湿式洗涤已经导致了显著的变化。在将云冰水路径从≈5.5 g m-2 增加到≈9.3 g m-2 的其他模拟中，对船舶废气扰动的反应更加微弱，但发现根据云的微物理状态，废气扰动甚至可能导致轻微的辐射冷却效应。因此，航运活动对北极云特性的区域影响可能在很大程度上取决于船舶燃料类型、船舶是否使用湿式洗涤器以及决定主要云特性的环境热力学条件。
{"title":"Potential impacts of marine fuel regulations on Arctic clouds and radiative feedbacks","authors":"Luís Filipe Escusa dos Santos, Hannah C. Frostenberg, Alejandro Baró Pérez, Annica M. L. Ekman, Luisa Ickes, Erik S. Thomson","doi":"10.5194/egusphere-2024-1891","DOIUrl":"https://doi.org/10.5194/egusphere-2024-1891","url":null,"abstract":"<strong>Abstract.</strong> Increased surface warming over the Arctic, triggered by increased greenhouse gas concentrations and feedback processes in the climate system, has been causing a steady decline in sea-ice extent and thickness. With the retreating sea-ice, shipping activity will likely increase in the future driven by economic activity and the potential for realizing time and fuel savings from transiting shorter trade routes. Moreover, over the last decade, the global shipping sector has been subject to regulatory changes, that affect the physicochemical properties of exhaust particles. International regulations aiming to reduce SO<sub>x</sub> and particulate matter (PM) emissions, mandate ships to burn fuels with reduced sulfur content or alternatively, use wet scrubbing as exhaust after-treatment when using fuels with sulfur contents exceeding regulatory limits. Compliance measures affect the physicochemical properties of exhaust particles and their cloud condensation nuclei (CCN) activity in different ways, with the potential to have both direct and indirect impacts on atmospheric processes such as the formation and lifetime of clouds. Given the relatively pristine Arctic environment, ship exhaust particle emissions could be a large perturbation to natural baseline Arctic aerosol concentrations. Low-level stratiform mixed-phase clouds cover large areas of the Arctic region and play an important role in the regional energy budget. Results from laboratory marine engine measurements, which investigated the impact of fuel sulfur content (FSC) reduction and wet scrubbing on exhaust particle properties, motivate the use of large eddy simulations to further investigate how such particles may influence the micro- and macrophysical properties of a stratiform mixed-phase cloud case observed during the Arctic Summer Cloud Ocean Study campaign. Simulated enhancements of ship exhaust particles predominantly affected the liquid-phase properties of the cloud and led to a decrease in liquid surface precipitation, increased cloud albedo and increased longwave surface warming. The magnitude of the impact strongly depended on ship exhaust particle concentration, hygroscopicity, and size where the effect of particle size dominated the impact of hygroscopicity. While low FSC exhaust particles were mostly observed to affect cloud properties at exhaust particle concentrations of 1000 cm<sup>-3</sup>, exhaust wet scrubbing already led to significant changes at concentrations of 100 cm<sup>-3</sup>. Additional simulations with cloud ice water path increased from ≈5.5 g m<sup>-2</sup> to ≈9.3 g m<sup>-2</sup>, show more muted responses to ship exhaust perturbations but revealed that exhaust perturbations may even lead to a slight radiative cooling effect depending on the microphysical state of the cloud. The regional impact of shipping activity on Arctic cloud properties may, therefore, strongly depend on ship fuel type, whether ships utilize wet scrubbers, and","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"33 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141462541","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 : 2024-06-27DOI: 10.5194/egusphere-2024-1808
Christian Mark Garcia Salvador, Jeffrey D. Wood, Emma Grace Cochran, Hunter A. Seubert, Bella D. Kamplain, Sam S. Overby, Kevin R. Birdwell, Lianhong Gu, Melanie A. Mayes
Abstract. Climate extremes are projected to cause unprecedented deviations in the emission and transformation of volatile organic compounds (VOCs), which trigger feedback mechanisms that will impact the atmospheric oxidation and formation of aerosols and clouds. However, the response of VOCs to future conditions such as extreme heat and wildfire events is still uncertain. This study explored the modification of the mixing ratio and distribution of several anthropogenic and biogenic VOCs in a temperate oak–hickory–juniper forest as a response to increased temperature and transported biomass burning plumes. A chemical ionization mass spectrometer was deployed on a tower at a height of 32 m in rural central Missouri, United States, for the continuous and in situ measurement of VOCs from June to August of 2023. The maximum observed temperature in the region was 38 °C, and during multiple episodes the temperature remained above 32 °C for several hours. Biogenic VOCs such as isoprene and monoterpene followed closely the temperature daily profile but at varying rates, whereas anthropogenic VOCs were insensitive to elevated temperature. During the measurement period, wildfire emissions were transported to the site and substantially increased the mixing ratios of acetonitrile and benzene, which are produced from burning of biomass. An in-depth analysis of the mass spectra revealed more than 250 minor compounds, such as formamide and methylglyoxal. The overall volatility, O:C, and H:C ratios of the extended list of VOCs responded to the changes in extreme heat and the presence of combustion plumes. Multivariate analysis also clustered the compounds into five factors, which highlighted the sources of the unaccounted-for VOCs. Overall, results here underscore the imminent effect of extreme heat and wildfire on VOC variability, which is important in understanding future interactions between climate and atmospheric chemistry.
{"title":"Extreme Heat and Wildfire Emissions Enhance Volatile Organic Compounds: Insights on Future Climate","authors":"Christian Mark Garcia Salvador, Jeffrey D. Wood, Emma Grace Cochran, Hunter A. Seubert, Bella D. Kamplain, Sam S. Overby, Kevin R. Birdwell, Lianhong Gu, Melanie A. Mayes","doi":"10.5194/egusphere-2024-1808","DOIUrl":"https://doi.org/10.5194/egusphere-2024-1808","url":null,"abstract":"<strong>Abstract.</strong> Climate extremes are projected to cause unprecedented deviations in the emission and transformation of volatile organic compounds (VOCs), which trigger feedback mechanisms that will impact the atmospheric oxidation and formation of aerosols and clouds. However, the response of VOCs to future conditions such as extreme heat and wildfire events is still uncertain. This study explored the modification of the mixing ratio and distribution of several anthropogenic and biogenic VOCs in a temperate oak–hickory–juniper forest as a response to increased temperature and transported biomass burning plumes. A chemical ionization mass spectrometer was deployed on a tower at a height of 32 m in rural central Missouri, United States, for the continuous and in situ measurement of VOCs from June to August of 2023. The maximum observed temperature in the region was 38 °C, and during multiple episodes the temperature remained above 32 °C for several hours. Biogenic VOCs such as isoprene and monoterpene followed closely the temperature daily profile but at varying rates, whereas anthropogenic VOCs were insensitive to elevated temperature. During the measurement period, wildfire emissions were transported to the site and substantially increased the mixing ratios of acetonitrile and benzene, which are produced from burning of biomass. An in-depth analysis of the mass spectra revealed more than 250 minor compounds, such as formamide and methylglyoxal. The overall volatility, O:C, and H:C ratios of the extended list of VOCs responded to the changes in extreme heat and the presence of combustion plumes. Multivariate analysis also clustered the compounds into five factors, which highlighted the sources of the unaccounted-for VOCs. Overall, results here underscore the imminent effect of extreme heat and wildfire on VOC variability, which is important in understanding future interactions between climate and atmospheric chemistry.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"8 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141462498","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 : 2024-06-27DOI: 10.5194/acp-24-7385-2024
Flora Maria Brocza, Peter Rafaj, Robert Sander, Fabian Wagner, Jenny Marie Jones
Abstract. Anthropogenic mercury (Hg) emissions to the atmosphere are a long-lived hazard to human and environmental health. The UN Minamata Convention on Mercury is seeking to lower anthropogenic mercury emissions through a mix of policies from banning certain Hg uses to reducing unintentional Hg release from different activities. In addition to independent Hg policy, strategies to mitigate greenhouse gases, particulate matter (PM) and SO2 may also lower Hg emissions as a co-benefit. This study uses the Greenhouse Gas–Air Pollution Interactions and Synergies (GAINS) model to examine the effect of different clean air and climate policies on future global Hg emissions. The baseline scenario assumes current trends for energy use and Hg emissions as well as current legislation for clean air, mercury and climate policy. In addition, we explore the impact of the Minamata Convention, the co-benefits of climate and stringent air pollution policies, and maximum feasible reduction measures for Hg. Hg emission projections until 2050 show noticeable reductions in combustion sectors for all scenarios due to a decrease in global fossil fuel and traditional biomass use, leading to emission reductions of 33 % at baseline and up to 90 % when combining stringent climate controls and the most efficient Hg controls. Cement and non-ferrous metal emissions increase in all scenarios with current air pollution policy but could be reduced by up to 72 % and 46 %, respectively, in 2050 with stringent Hg-specific measures. Other emissions (including waste) are a significant source of uncertainty in this study, and their projections range between a 22 % increase and a 54 % decrease in 2050, depending on both climate and clean air policy. The largest absolute reduction potential for Hg abatement but also the largest uncertainties regarding absolute emissions lie in small-scale and artisanal gold production, where abatement measures could eliminate annual Hg emissions in the range of 601–1371 t (95 % confidence interval), although the uncertainties in the estimate are so high that they might eclipse reduction efforts in all other sectors. In total, 90 % of Hg emissions are covered by provisions of the Minamata Convention. Overall, the findings emphasize the necessity to implement targeted Hg control policies in addition to stringent climate, PM and SO2 policies to achieve significant reductions in Hg emissions.
{"title":"Global scenarios of anthropogenic mercury emissions","authors":"Flora Maria Brocza, Peter Rafaj, Robert Sander, Fabian Wagner, Jenny Marie Jones","doi":"10.5194/acp-24-7385-2024","DOIUrl":"https://doi.org/10.5194/acp-24-7385-2024","url":null,"abstract":"Abstract. Anthropogenic mercury (Hg) emissions to the atmosphere are a long-lived hazard to human and environmental health. The UN Minamata Convention on Mercury is seeking to lower anthropogenic mercury emissions through a mix of policies from banning certain Hg uses to reducing unintentional Hg release from different activities. In addition to independent Hg policy, strategies to mitigate greenhouse gases, particulate matter (PM) and SO2 may also lower Hg emissions as a co-benefit. This study uses the Greenhouse Gas–Air Pollution Interactions and Synergies (GAINS) model to examine the effect of different clean air and climate policies on future global Hg emissions. The baseline scenario assumes current trends for energy use and Hg emissions as well as current legislation for clean air, mercury and climate policy. In addition, we explore the impact of the Minamata Convention, the co-benefits of climate and stringent air pollution policies, and maximum feasible reduction measures for Hg. Hg emission projections until 2050 show noticeable reductions in combustion sectors for all scenarios due to a decrease in global fossil fuel and traditional biomass use, leading to emission reductions of 33 % at baseline and up to 90 % when combining stringent climate controls and the most efficient Hg controls. Cement and non-ferrous metal emissions increase in all scenarios with current air pollution policy but could be reduced by up to 72 % and 46 %, respectively, in 2050 with stringent Hg-specific measures. Other emissions (including waste) are a significant source of uncertainty in this study, and their projections range between a 22 % increase and a 54 % decrease in 2050, depending on both climate and clean air policy. The largest absolute reduction potential for Hg abatement but also the largest uncertainties regarding absolute emissions lie in small-scale and artisanal gold production, where abatement measures could eliminate annual Hg emissions in the range of 601–1371 t (95 % confidence interval), although the uncertainties in the estimate are so high that they might eclipse reduction efforts in all other sectors. In total, 90 % of Hg emissions are covered by provisions of the Minamata Convention. Overall, the findings emphasize the necessity to implement targeted Hg control policies in addition to stringent climate, PM and SO2 policies to achieve significant reductions in Hg emissions.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"22 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141461946","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. Cold extremes have large impacts on human society. Understanding the physical processes dominating the changes in cold extremes is crucial for a reliable projection of future climate change. The observed cold extremes have decreased during the last several decades, and this trend will continue under future global warming. Here, we quantitatively identify the contributions of dynamic (changes in large-scale atmospheric circulation) and thermodynamic (rising temperatures resulting from global warming) effects to East Asian cold extremes in the past several decades and in a future warm climate by using two sets of large-ensemble simulations of climate models. We show that the dynamic component accounts for over 80 % of the cold-month (coldest 5 % boreal winter months) surface air temperature (SAT) anomaly over the past 5 decades. However, in a future warm climate, the thermodynamic change is the main contributor to the decreases in the intensity and occurrence probability of East Asian cold extremes, while the dynamic change is also contributive. The intensity of East Asian cold extremes will decrease by around 5 °C at the end of the 21st century, in which the thermodynamic (dynamic) change contributes approximately 75 % (25 %). The present-day (1986–2005) East Asian cold extremes will almost never occur after around 2035, and this will happen 10 years later due solely to thermodynamic change. The upward trend of a positive Arctic Oscillation-like sea level pressure pattern dominates the changes in the dynamic component. The finding provides a useful reference for policymakers in climate change adaptation activities.
{"title":"Future reduction of cold extremes over East Asia due to thermodynamic and dynamic warming","authors":"Donghuan Li, Tianjun Zhou, Youcun Qi, Liwei Zou, Chao Li, Wenxia Zhang, Xiaolong Chen","doi":"10.5194/acp-24-7347-2024","DOIUrl":"https://doi.org/10.5194/acp-24-7347-2024","url":null,"abstract":"Abstract. Cold extremes have large impacts on human society. Understanding the physical processes dominating the changes in cold extremes is crucial for a reliable projection of future climate change. The observed cold extremes have decreased during the last several decades, and this trend will continue under future global warming. Here, we quantitatively identify the contributions of dynamic (changes in large-scale atmospheric circulation) and thermodynamic (rising temperatures resulting from global warming) effects to East Asian cold extremes in the past several decades and in a future warm climate by using two sets of large-ensemble simulations of climate models. We show that the dynamic component accounts for over 80 % of the cold-month (coldest 5 % boreal winter months) surface air temperature (SAT) anomaly over the past 5 decades. However, in a future warm climate, the thermodynamic change is the main contributor to the decreases in the intensity and occurrence probability of East Asian cold extremes, while the dynamic change is also contributive. The intensity of East Asian cold extremes will decrease by around 5 °C at the end of the 21st century, in which the thermodynamic (dynamic) change contributes approximately 75 % (25 %). The present-day (1986–2005) East Asian cold extremes will almost never occur after around 2035, and this will happen 10 years later due solely to thermodynamic change. The upward trend of a positive Arctic Oscillation-like sea level pressure pattern dominates the changes in the dynamic component. The finding provides a useful reference for policymakers in climate change adaptation activities.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"38 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141461805","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 : 2024-06-26DOI: 10.5194/egusphere-2024-1848
Feng Jiang, Harald Saathoff, Junwei Song, Hengheng Zhang, Linyu Gao, Thomas Leisner
Abstract. Brown carbon aerosol (BrC) is one major contributor to atmospheric air pollution in Europe, especially in winter. Therefore, we studied the chemical composition, diurnal variation, and sources of BrC from 17th February to 16th March at a rural location in southwest Germany. In total, 178 potential BrC molecules (including 7 nitro aromatic compounds, NACs) were identified in the particle phase comprising on average 63 ± 32 ng m−3, and 31 potential BrC (including 4 NACs) molecules were identified in the gas phase contributing on average 6.2 ± 5.0 ng m−3 during the whole campaign. The 178 potential BrC molecules only accounted for 2.3 ± 1.5 % of the total organic mass, but can explain 11 ± 11 % of the total BrC absorption at 370 nm, assuming an average mass absorption coefficient at 370 nm (MAC370) of 9.5 m2 g−1. A few BrC molecules dominated the total BrC absorption. In addition, diurnal variations show that gas phase BrC was higher at daytime and lower at night. It was mainly controlled by secondary formation (e.g. photooxidation) and particle-to-gas partitioning. Correspondingly, the particle phase BrC was lower at daytime and higher at nighttime. Secondary formation dominates the particle-phase BrC with 61 ± 21 %, while 39 ± 21 % originated from biomass burning. Furthermore, the particle-phase BrC showed decreasing light absorption due to photochemical aging. This study extends the current understanding of real-time behaviors of brown carbon aerosol in the gas and particle phase at a location characteristic for the central Europe.
{"title":"Brown carbon aerosol in rural Germany: sources, chemistry, and diurnal variations","authors":"Feng Jiang, Harald Saathoff, Junwei Song, Hengheng Zhang, Linyu Gao, Thomas Leisner","doi":"10.5194/egusphere-2024-1848","DOIUrl":"https://doi.org/10.5194/egusphere-2024-1848","url":null,"abstract":"<strong>Abstract.</strong> Brown carbon aerosol (BrC) is one major contributor to atmospheric air pollution in Europe, especially in winter. Therefore, we studied the chemical composition, diurnal variation, and sources of BrC from 17<sup>th</sup> February to 16<sup>th</sup> March at a rural location in southwest Germany. In total, 178 potential BrC molecules (including 7 nitro aromatic compounds, NACs) were identified in the particle phase comprising on average 63 ± 32 ng m<sup>−3</sup>, and 31 potential BrC (including 4 NACs) molecules were identified in the gas phase contributing on average 6.2 ± 5.0 ng m<sup>−3</sup> during the whole campaign. The 178 potential BrC molecules only accounted for 2.3 ± 1.5 % of the total organic mass, but can explain 11 ± 11 % of the total BrC absorption at 370 nm, assuming an average mass absorption coefficient at 370 nm (MAC<sub>370</sub>) of 9.5 m<sup>2</sup> g<sup>−1</sup>. A few BrC molecules dominated the total BrC absorption. In addition, diurnal variations show that gas phase BrC was higher at daytime and lower at night. It was mainly controlled by secondary formation (e.g. photooxidation) and particle-to-gas partitioning. Correspondingly, the particle phase BrC was lower at daytime and higher at nighttime. Secondary formation dominates the particle-phase BrC with 61 ± 21 %, while 39 ± 21 % originated from biomass burning. Furthermore, the particle-phase BrC showed decreasing light absorption due to photochemical aging. This study extends the current understanding of real-time behaviors of brown carbon aerosol in the gas and particle phase at a location characteristic for the central Europe.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"17 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141452907","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 : 2024-06-26DOI: 10.5194/acp-24-7309-2024
Haklim Choi, Alison L. Redington, Hyeri Park, Jooil Kim, Rona L. Thompson, Jens Mühle, Peter K. Salameh, Christina M. Harth, Ray F. Weiss, Alistair J. Manning, Sunyoung Park
Abstract. Hydrofluorocarbons (HFCs) are powerful anthropogenic greenhouse gases (GHGs) with high global-warming potentials (GWPs). They have been widely used as refrigerants, insulation foam-blowing agents, aerosol propellants, and fire suppression agents. Since the mid-1990s, emissions of HFCs have been increasing rapidly as they are used in many applications to replace ozone-depleting chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) whose consumption and production have been phased out under the Montreal Protocol (MP). Due to the high GWP of HFCs, the Kigali Amendment to the MP requires the phasedown of production and consumption of HFCs to gradually achieve an 80 %–85 % reduction by 2047, starting in 2019 for non-Article 5 (developed) countries with a 10 % reduction against each defined baseline and later schedules for Article 5 (developing) countries. In this study, we have examined long-term high-precision measurements of atmospheric abundances of five major HFCs (HFC-134a, HFC-143a, HFC-32, HFC-125, and HFC-152a) at Gosan station, Jeju Island, South Korea, from 2008 to 2020. Background abundances of HFCs gradually increased, and the inflow of polluted air masses with elevated abundances from surrounding source regions were detected over the entire period. From these pollution events, we inferred regional and country-specific HFC emission estimates using two independent Lagrangian particle dispersion models and Bayesian inversion frameworks (FLEXPART-FLEXINVERT+ and NAME-InTEM). The spatial distribution of the derived “top-down” (measurement based) emissions for all HFCs shows large fluxes from megacities and industrial areas in the region. Our most important finding is that HFC emissions in eastern China and Japan have sharply increased from 2016 to 2018. The contribution of East Asian HFC emissions to the global total increased from 9 % (2008–2014) to 13 % (2016–2020). In particular, HFC emissions in Japan (Annex I country) rose rapidly from 2016 onward, with accumulated total inferred HFC emissions being ∼ 114 Gg yr−1, which is ∼ 76 Gg yr−1 higher for 2016–2020 than the “bottom-up” (i.e., based on activity data and emission factors) emissions of ∼ 38 Gg yr−1 reported to the United Nations Framework Convention on Climate Change (UNFCCC). This is likely related to the increase in domestic demand in Japan for refrigerants and air-conditioning-system-related products and incomplete accounting. A downward trend of HFC emissions that started in 2019 reflects the effectiveness of the F-gas policy in Japan. Eastern China and South Korea, though not obligated to report to the UNFCCC, voluntarily reported emissions, which also show differences between top-down and bottom-up emission estimates, demonstrating the need for atmospheric measurements, comprehensive data analysis, and accurate reporting for precise emission management. Further, the proportional contribution of each country's CO2-equivalent HFC emissions has changed over tim
{"title":"Revealing the significant acceleration of hydrofluorocarbon (HFC) emissions in eastern Asia through long-term atmospheric observations","authors":"Haklim Choi, Alison L. Redington, Hyeri Park, Jooil Kim, Rona L. Thompson, Jens Mühle, Peter K. Salameh, Christina M. Harth, Ray F. Weiss, Alistair J. Manning, Sunyoung Park","doi":"10.5194/acp-24-7309-2024","DOIUrl":"https://doi.org/10.5194/acp-24-7309-2024","url":null,"abstract":"Abstract. Hydrofluorocarbons (HFCs) are powerful anthropogenic greenhouse gases (GHGs) with high global-warming potentials (GWPs). They have been widely used as refrigerants, insulation foam-blowing agents, aerosol propellants, and fire suppression agents. Since the mid-1990s, emissions of HFCs have been increasing rapidly as they are used in many applications to replace ozone-depleting chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) whose consumption and production have been phased out under the Montreal Protocol (MP). Due to the high GWP of HFCs, the Kigali Amendment to the MP requires the phasedown of production and consumption of HFCs to gradually achieve an 80 %–85 % reduction by 2047, starting in 2019 for non-Article 5 (developed) countries with a 10 % reduction against each defined baseline and later schedules for Article 5 (developing) countries. In this study, we have examined long-term high-precision measurements of atmospheric abundances of five major HFCs (HFC-134a, HFC-143a, HFC-32, HFC-125, and HFC-152a) at Gosan station, Jeju Island, South Korea, from 2008 to 2020. Background abundances of HFCs gradually increased, and the inflow of polluted air masses with elevated abundances from surrounding source regions were detected over the entire period. From these pollution events, we inferred regional and country-specific HFC emission estimates using two independent Lagrangian particle dispersion models and Bayesian inversion frameworks (FLEXPART-FLEXINVERT+ and NAME-InTEM). The spatial distribution of the derived “top-down” (measurement based) emissions for all HFCs shows large fluxes from megacities and industrial areas in the region. Our most important finding is that HFC emissions in eastern China and Japan have sharply increased from 2016 to 2018. The contribution of East Asian HFC emissions to the global total increased from 9 % (2008–2014) to 13 % (2016–2020). In particular, HFC emissions in Japan (Annex I country) rose rapidly from 2016 onward, with accumulated total inferred HFC emissions being ∼ 114 Gg yr−1, which is ∼ 76 Gg yr−1 higher for 2016–2020 than the “bottom-up” (i.e., based on activity data and emission factors) emissions of ∼ 38 Gg yr−1 reported to the United Nations Framework Convention on Climate Change (UNFCCC). This is likely related to the increase in domestic demand in Japan for refrigerants and air-conditioning-system-related products and incomplete accounting. A downward trend of HFC emissions that started in 2019 reflects the effectiveness of the F-gas policy in Japan. Eastern China and South Korea, though not obligated to report to the UNFCCC, voluntarily reported emissions, which also show differences between top-down and bottom-up emission estimates, demonstrating the need for atmospheric measurements, comprehensive data analysis, and accurate reporting for precise emission management. Further, the proportional contribution of each country's CO2-equivalent HFC emissions has changed over tim","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"12 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141452807","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. The capacity of particulate matter (PM) to generate reactive oxygen species (ROS) in vivo leading to oxidative stress is thought to be a main pathway in the health effects of PM inhalation. Exogenous ROS from PM can be assessed by acellular oxidative potential (OP) measurements as a proxy of the induction of oxidative stress in the lungs. Here, we investigate the importance of OP apportionment methods for OP distribution by PM10 sources in different types of environments. PM10 sources derived from receptor models (e.g., EPA positive matrix factorization (EPA PMF)) are coupled with regression models expressing the associations between PM10 sources and PM10 OP measured by ascorbic acid (OPAA) and dithiothreitol assay (OPDTT). These relationships are compared for eight regression techniques: ordinary least squares, weighted least squares, positive least squares, Ridge, Lasso, generalized linear model, random forest, and multilayer perceptron. The models are evaluated on 1 year of PM10 samples and chemical analyses at each of six sites of different typologies in France to assess the possible impact of PM source variability on PM10 OP apportionment. PM10 source-specific OPDTT and OPAA and out-of-sample apportionment accuracy vary substantially by model, highlighting the importance of model selection according to the datasets. Recommendations for the selection of the most accurate model are provided, encompassing considerations such as multicollinearity and homoscedasticity.
摘要颗粒物（PM）在体内产生活性氧（ROS）导致氧化应激的能力被认为是吸入颗粒物影响健康的主要途径。可吸入颗粒物产生的外源性 ROS 可通过细胞氧化电位（OP）测量来评估，以此作为肺部氧化应激诱导的替代物。在这里，我们研究了不同类型环境中 PM10 来源的 OP 分布的 OP 分摊方法的重要性。从受体模型（如 EPA 正矩阵因式分解（EPA PMF））得出的 PM10 来源与表达 PM10 来源与通过抗坏血酸（OPAA）和二硫苏糖醇测定法（OPDTT）测量的 PM10 OP 之间关系的回归模型相结合。这些关系通过八种回归技术进行了比较：普通最小二乘法、加权最小二乘法、正最小二乘法、Ridge、Lasso、广义线性模型、随机森林和多层感知器。这些模型对法国六个不同类型地点的一年 PM10 样品和化学分析进行了评估，以评估 PM10 源变异性对 PM10 OP 分配可能产生的影响。不同模型的PM10特定源OPDTT和OPAA以及样本外分摊的准确性差异很大，这突出了根据数据集选择模型的重要性。提供了选择最准确模型的建议，包括多共线性和同方差等考虑因素。
{"title":"Unveiling the optimal regression model for source apportionment of the oxidative potential of PM10","authors":"Vy Dinh Ngoc Thuy, Jean-Luc Jaffrezo, Ian Hough, Pamela A. Dominutti, Guillaume Salque Moreton, Grégory Gille, Florie Francony, Arabelle Patron-Anquez, Olivier Favez, Gaëlle Uzu","doi":"10.5194/acp-24-7261-2024","DOIUrl":"https://doi.org/10.5194/acp-24-7261-2024","url":null,"abstract":"Abstract. The capacity of particulate matter (PM) to generate reactive oxygen species (ROS) in vivo leading to oxidative stress is thought to be a main pathway in the health effects of PM inhalation. Exogenous ROS from PM can be assessed by acellular oxidative potential (OP) measurements as a proxy of the induction of oxidative stress in the lungs. Here, we investigate the importance of OP apportionment methods for OP distribution by PM10 sources in different types of environments. PM10 sources derived from receptor models (e.g., EPA positive matrix factorization (EPA PMF)) are coupled with regression models expressing the associations between PM10 sources and PM10 OP measured by ascorbic acid (OPAA) and dithiothreitol assay (OPDTT). These relationships are compared for eight regression techniques: ordinary least squares, weighted least squares, positive least squares, Ridge, Lasso, generalized linear model, random forest, and multilayer perceptron. The models are evaluated on 1 year of PM10 samples and chemical analyses at each of six sites of different typologies in France to assess the possible impact of PM source variability on PM10 OP apportionment. PM10 source-specific OPDTT and OPAA and out-of-sample apportionment accuracy vary substantially by model, highlighting the importance of model selection according to the datasets. Recommendations for the selection of the most accurate model are provided, encompassing considerations such as multicollinearity and homoscedasticity.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"43 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141452918","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 : 2024-06-26DOI: 10.5194/acp-24-7283-2024
Donatello Gallucci, Domenico Cimini, Emma Turner, Stuart Fox, Philip W. Rosenkranz, Mikhail Y. Tretyakov, Vinia Mattioli, Salvatore Larosa, Filomena Romano
Abstract. Atmospheric radiative transfer models are extensively used in Earth observation to simulate radiative processes occurring in the atmosphere and to provide both upwelling and downwelling synthetic brightness temperatures for ground-based, airborne, and satellite radiometric sensors. For a meaningful comparison between simulated and observed radiances, it is crucial to characterize the uncertainty in such models. The purpose of this work is to quantify the uncertainty in radiative transfer models due to uncertainty in the associated spectroscopic parameters and to compute simulated brightness temperature uncertainties for millimeter- and submillimeter-wave channels of downward-looking satellite radiometric sensors (MicroWave Imager, MWI; Ice Cloud Imager, ICI; MicroWave Sounder, MWS; and Advanced Technology Microwave Sounder, ATMS) as well as upward-looking airborne radiometers (International Submillimetre Airborne Radiometer, ISMAR, and Microwave Airborne Radiometer Scanning System, MARSS). The approach adopted here is firstly to study the sensitivity of brightness temperature calculations to each spectroscopic parameter separately, then to identify the dominant parameters and investigate their uncertainty covariance, and finally to compute the total brightness temperature uncertainty due to the full uncertainty covariance matrix for the identified set of relevant spectroscopic parameters. The approach is applied to a recent version of the Millimeter-wave Propagation Model, taking into account water vapor, oxygen, and ozone spectroscopic parameters, though the approach is general and can be applied to any radiative transfer code. A set of 135 spectroscopic parameters were identified as dominant for the uncertainty in simulated brightness temperatures (26 for water vapor, 109 for oxygen, none for ozone). The uncertainty in simulated brightness temperatures is computed for six climatology conditions (ranging from sub-Arctic winter to tropical) and all instrument channels. Uncertainty is found to be up to few kelvins [K] in the millimeter-wave range, whereas it is considerably lower in the submillimeter-wave range (less than 1 K).
{"title":"Uncertainty in simulated brightness temperature due to sensitivity to atmospheric gas spectroscopic parameters from the centimeter- to submillimeter-wave range","authors":"Donatello Gallucci, Domenico Cimini, Emma Turner, Stuart Fox, Philip W. Rosenkranz, Mikhail Y. Tretyakov, Vinia Mattioli, Salvatore Larosa, Filomena Romano","doi":"10.5194/acp-24-7283-2024","DOIUrl":"https://doi.org/10.5194/acp-24-7283-2024","url":null,"abstract":"Abstract. Atmospheric radiative transfer models are extensively used in Earth observation to simulate radiative processes occurring in the atmosphere and to provide both upwelling and downwelling synthetic brightness temperatures for ground-based, airborne, and satellite radiometric sensors. For a meaningful comparison between simulated and observed radiances, it is crucial to characterize the uncertainty in such models. The purpose of this work is to quantify the uncertainty in radiative transfer models due to uncertainty in the associated spectroscopic parameters and to compute simulated brightness temperature uncertainties for millimeter- and submillimeter-wave channels of downward-looking satellite radiometric sensors (MicroWave Imager, MWI; Ice Cloud Imager, ICI; MicroWave Sounder, MWS; and Advanced Technology Microwave Sounder, ATMS) as well as upward-looking airborne radiometers (International Submillimetre Airborne Radiometer, ISMAR, and Microwave Airborne Radiometer Scanning System, MARSS). The approach adopted here is firstly to study the sensitivity of brightness temperature calculations to each spectroscopic parameter separately, then to identify the dominant parameters and investigate their uncertainty covariance, and finally to compute the total brightness temperature uncertainty due to the full uncertainty covariance matrix for the identified set of relevant spectroscopic parameters. The approach is applied to a recent version of the Millimeter-wave Propagation Model, taking into account water vapor, oxygen, and ozone spectroscopic parameters, though the approach is general and can be applied to any radiative transfer code. A set of 135 spectroscopic parameters were identified as dominant for the uncertainty in simulated brightness temperatures (26 for water vapor, 109 for oxygen, none for ozone). The uncertainty in simulated brightness temperatures is computed for six climatology conditions (ranging from sub-Arctic winter to tropical) and all instrument channels. Uncertainty is found to be up to few kelvins [K] in the millimeter-wave range, whereas it is considerably lower in the submillimeter-wave range (less than 1 K).","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"27 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141453075","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 : 2024-06-25DOI: 10.5194/egusphere-2024-1880
Rui Jin, Wei Hu, Peimin Duan, Ming Sheng, Dandan Liu, Ziye Huang, Mutong Niu, Libin Wu, Junjun Deng, Pingqing Fu
Abstract. The interactions of metabolically active atmospheric microorganisms with cloud organic matter can alter the atmospheric carbon cycle. Upon deposition, atmospheric microorganisms can influence microbial communities in surface Earth systems. However, the metabolic activities of cultivable atmospheric microorganisms in settled habitats remain less understood. Here, we investigated exometabolites produced by typical bacterial and fungal species isolated from the urban atmosphere to elucidate their biogeochemical roles. Molecular compositions of exometabolites were analyzed using ultra-high resolution Fourier transform ion cyclotron resonance mass spectrometry. Annotation through the Kyoto Encyclopedia of Genes and Genomes database helped identify metabolic processes. Results showed that bacterial and fungal strains produce exometabolites with lower H/C and higher O/C ratios than consumed and resistant compounds. CHON compounds constituted over 50 % of the identified formulas of exometabolites. Bacterial exometabolites contained more abundant CHONS compounds (25.2 %), while fungal exometabolites were rich in CHO compounds (31.7 %). These microbial exometabolites predominantly comprised aliphatic/peptide-like and carboxyl-rich alicyclic molecules (CRAM-like). Significant variations in metabolites were observed among different strains. Bacteria showed a performance for amino acid synthesis, while fungi were more active in transcription and expression processes. Lipid metabolism, amino acid metabolism, and carbohydrate metabolism varied widely among bacterial strains, while fungi exhibited marked differences in carbohydrate metabolism and secondary metabolism. This comprehensive examination of metabolite characteristics at the molecular level for typical culturable airborne microorganisms enhances our understanding of their potential metabolic activities at air-land/water interfaces. These insights are pivotal for assessing the biogeochemical impacts of atmospheric microorganisms following their deposition.
摘要代谢活跃的大气微生物与云层有机物的相互作用可改变大气碳循环。大气微生物在沉积后会影响地球表面系统中的微生物群落。然而，人们对定居栖息地中可培养的大气微生物的代谢活动仍然知之甚少。在这里，我们研究了从城市大气中分离出来的典型细菌和真菌物种产生的外代谢产物，以阐明它们的生物地球化学作用。我们使用超高分辨率傅立叶变换离子回旋共振质谱分析了外代谢物的分子组成。通过京都基因和基因组百科全书数据库进行注释，有助于确定代谢过程。结果表明，细菌和真菌菌株产生的外代谢物与消耗性和抗性化合物相比，H/C 比值较低，O/C 比值较高。在已鉴定的外代谢物配方中，CHON化合物占了50%以上。细菌外代谢物含有更多的 CHONS 化合物（25.2%），而真菌外代谢物则富含 CHO 化合物（31.7%）。这些微生物外代谢物主要包括脂肪族/肽类和富含羧基的脂环族分子（CRAM-like）。不同菌株的代谢物存在显著差异。细菌在氨基酸合成方面表现突出，而真菌在转录和表达过程中更为活跃。细菌菌株之间的脂质代谢、氨基酸代谢和碳水化合物代谢差异很大，而真菌在碳水化合物代谢和次级代谢方面表现出明显差异。对典型的可培养空气传播微生物的代谢物特征进行分子水平的全面研究，加深了我们对它们在空气-陆地-水界面的潜在代谢活动的了解。这些见解对于评估大气微生物沉积后的生物地球化学影响至关重要。
{"title":"Exometabolomic exploration of culturable airborne microorganisms from an urban atmosphere","authors":"Rui Jin, Wei Hu, Peimin Duan, Ming Sheng, Dandan Liu, Ziye Huang, Mutong Niu, Libin Wu, Junjun Deng, Pingqing Fu","doi":"10.5194/egusphere-2024-1880","DOIUrl":"https://doi.org/10.5194/egusphere-2024-1880","url":null,"abstract":"<strong>Abstract.</strong> The interactions of metabolically active atmospheric microorganisms with cloud organic matter can alter the atmospheric carbon cycle. Upon deposition, atmospheric microorganisms can influence microbial communities in surface Earth systems. However, the metabolic activities of cultivable atmospheric microorganisms in settled habitats remain less understood. Here, we investigated exometabolites produced by typical bacterial and fungal species isolated from the urban atmosphere to elucidate their biogeochemical roles. Molecular compositions of exometabolites were analyzed using ultra-high resolution Fourier transform ion cyclotron resonance mass spectrometry. Annotation through the Kyoto Encyclopedia of Genes and Genomes database helped identify metabolic processes. Results showed that bacterial and fungal strains produce exometabolites with lower H/C and higher O/C ratios than consumed and resistant compounds. CHON compounds constituted over 50 % of the identified formulas of exometabolites. Bacterial exometabolites contained more abundant CHONS compounds (25.2 %), while fungal exometabolites were rich in CHO compounds (31.7 %). These microbial exometabolites predominantly comprised aliphatic/peptide-like and carboxyl-rich alicyclic molecules (CRAM-like). Significant variations in metabolites were observed among different strains. Bacteria showed a performance for amino acid synthesis, while fungi were more active in transcription and expression processes. Lipid metabolism, amino acid metabolism, and carbohydrate metabolism varied widely among bacterial strains, while fungi exhibited marked differences in carbohydrate metabolism and secondary metabolism. This comprehensive examination of metabolite characteristics at the molecular level for typical culturable airborne microorganisms enhances our understanding of their potential metabolic activities at air-land/water interfaces. These insights are pivotal for assessing the biogeochemical impacts of atmospheric microorganisms following their deposition.","PeriodicalId":8611,"journal":{"name":"Atmospheric Chemistry and Physics","volume":"27 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141452863","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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