Pub Date : 2025-11-28DOI: 10.1016/j.atmosres.2025.108665
Guitong Dong , Yongqing Wang , Li Tao
The multi-scale structural characteristics of Vortex Rossby Wave (VRW) propagating in the inner and outer eyewalls as well as spiral rainbands are examined. This is done by applying the Multiscale Window Transform (MWT) and the MWT-based localized multiscale energy and vorticity analysis method (MS-EVA) to a successful high-resolution simulation of Super Typhoon Lekima (1909) with the Weather Research and Forecasting (WRF) model, and then decomposing and reconstructing geopotential, temperature, three-dimensional wind fields, potential vorticity (PV), radar reflectivity and vertical relative vorticity into the following three spatial scales: mean vortex flow, low-wavenumber and high-wavenumber flows. Results show that both low-wavenumber and high-wavenumber waves conform to VRW's wind-pressure relationship, demonstrating MWT's advantage in capturing VRW's local structures. Based on MS-EVA, this study illustrates during secondary eyewall formation and contraction (1) three types of wave-mean flow interactions manifested by VRW (cross-scale kinetic energy transfer, large-scale kinetic energy transport by small-scale waves, and cross-scale enstrophy transfer) and (2) basic-flow-scale kinetic energy transport and pressure work, illustrating their impact mechanisms on basic-flow-scale kinetic energy variations in the secondary eyewall.
{"title":"Multiscale structural characteristics of the Vortex Rossby Wave of Super Typhoon Lekima (1909) and its interaction with the mean flow","authors":"Guitong Dong , Yongqing Wang , Li Tao","doi":"10.1016/j.atmosres.2025.108665","DOIUrl":"10.1016/j.atmosres.2025.108665","url":null,"abstract":"<div><div>The multi-scale structural characteristics of Vortex Rossby Wave (VRW) propagating in the inner and outer eyewalls as well as spiral rainbands are examined. This is done by applying the Multiscale Window Transform (MWT) and the MWT-based localized multiscale energy and vorticity analysis method (MS-EVA) to a successful high-resolution simulation of Super Typhoon Lekima (1909) with the Weather Research and Forecasting (WRF) model, and then decomposing and reconstructing geopotential, temperature, three-dimensional wind fields, potential vorticity (PV), radar reflectivity and vertical relative vorticity into the following three spatial scales: mean vortex flow, low-wavenumber and high-wavenumber flows. Results show that both low-wavenumber and high-wavenumber waves conform to VRW's wind-pressure relationship, demonstrating MWT's advantage in capturing VRW's local structures. Based on MS-EVA, this study illustrates during secondary eyewall formation and contraction (1) three types of wave-mean flow interactions manifested by VRW (cross-scale kinetic energy transfer, large-scale kinetic energy transport by small-scale waves, and cross-scale enstrophy transfer) and (2) basic-flow-scale kinetic energy transport and pressure work, illustrating their impact mechanisms on basic-flow-scale kinetic energy variations in the secondary eyewall.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"331 ","pages":"Article 108665"},"PeriodicalIF":4.4,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145613778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The atmospheric electric field in fair-weather conditions, typically quantified by the Potential Gradient (PG, which is the inverse of the vertical component of the electric field), is a fundamental element of the global electric circuit. It is sensitive to multiple scales of influence, including global atmospheric dynamics, local meteorological conditions (e.g., dust, fog, clouds), and anthropogenic factors such as air pollution. In this study, we analyze PG measurements from a newly deployed electric field mill installed in the metropolitan area of Tel-Aviv area, the urban part of central Israel, which has been operational since August 2024. This instrument is part of a broader observational network that includes nearby meteorological and air quality monitoring stations, allowing for a comprehensive assessment of the factors influencing PG variability.
Focusing on fair-weather conditions, we investigate both diurnal, weekly, and seasonal patterns of PG and their relation to pollutant concentrations. Our findings reveal a distinct temporal correlation between the PG and NOₓ levels during the morning and evening rush hours, indicating rapid atmospheric responses to traffic-related emissions. In contrast, elevated PM2.5 concentrations are associated with a delayed PG response, likely due to their longer atmospheric residence time and different microphysical interactions. Furthermore, a pronounced ‘weekend effect’ is observed, with reduced pollution and correspondingly altered PG values on weekends compared with weekdays, highlighting the measurable impact of human activity on atmospheric electricity.
These results enhance our understanding of the interplay between urban air pollution and the local electric field, and emphasize the importance of integrating air quality data into atmospheric electricity studies, particularly in densely populated regions where anthropogenic influences are pronounced, with implications for public health.
{"title":"Effects of urban air pollution on the fair-weather electric field in the Tel-Aviv, Israel metropolitan area","authors":"Roy Yaniv , Itay Froomer , Yoav Yair , Assaf Hochman","doi":"10.1016/j.atmosres.2025.108661","DOIUrl":"10.1016/j.atmosres.2025.108661","url":null,"abstract":"<div><div>The atmospheric electric field in fair-weather conditions, typically quantified by the Potential Gradient (PG, which is the inverse of the vertical component of the electric field), is a fundamental element of the global electric circuit. It is sensitive to multiple scales of influence, including global atmospheric dynamics, local meteorological conditions (e.g., dust, fog, clouds), and anthropogenic factors such as air pollution. In this study, we analyze PG measurements from a newly deployed electric field mill installed in the metropolitan area of Tel-Aviv area, the urban part of central Israel, which has been operational since August 2024. This instrument is part of a broader observational network that includes nearby meteorological and air quality monitoring stations, allowing for a comprehensive assessment of the factors influencing PG variability.</div><div>Focusing on fair-weather conditions, we investigate both diurnal, weekly, and seasonal patterns of PG and their relation to pollutant concentrations. Our findings reveal a distinct temporal correlation between the PG and NOₓ levels during the morning and evening rush hours, indicating rapid atmospheric responses to traffic-related emissions. In contrast, elevated PM2.5 concentrations are associated with a delayed PG response, likely due to their longer atmospheric residence time and different microphysical interactions. Furthermore, a pronounced ‘weekend effect’ is observed, with reduced pollution and correspondingly altered PG values on weekends compared with weekdays, highlighting the measurable impact of human activity on atmospheric electricity.</div><div>These results enhance our understanding of the interplay between urban air pollution and the local electric field, and emphasize the importance of integrating air quality data into atmospheric electricity studies, particularly in densely populated regions where anthropogenic influences are pronounced, with implications for public health.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"331 ","pages":"Article 108661"},"PeriodicalIF":4.4,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145613695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-11-28DOI: 10.1016/j.atmosres.2025.108664
Huan Ren , Gaopeng Lu , Hailiang Huang , Liyu Wang , Yun Bi , Xiaoyang Zhang , Ziyi Wang
<div><div>With the contribution of Chinese sprite enthusiast, the observation of 165 Transient Luminous Events (TLEs) (almost over 98 % being sprites) over Central South China during the delayed pre-rainy season of South China on three consecutive nights of May 10th–12th, 2021 are reported. The convective cores exhibited the minimum Temperature of Black Body (TBB) of cloud top within the range of 180 to 190 K within 10 min of sprite occurrence, which extended up to or beyond the tropopause (∼ 17 km, 195 K) and was colder (more than 15 K) than that of regular TLEs-producing mesoscale convective systems (MCSs) in the central USA. However, the sprite distribution was closely associated with regions of TBB averaging 216.5 K, about 10 K warmer than that of the central USA. This distinct behavior of TLEs-producing thunderstorms in South China can be attributed to a combination of intricate meteorological and topographic factors. Firstly, in addition to the influence of the Subtropical High Pressure Zone, the positioned farther west and north compared to previous years caused the convergence of warm water vapor from the South China Sea and cold air from the north, coupled with the Southwest Vortex (SWV) and multi-layer jets, fostering intense convection. Besides, the intricate plateau and mountain topography are likely also responsible for the distinct behavior of TLEs-producing thunderstorm. Thus, more attention should be paid on thunderstorms in South China during the pre-rainy season for the future study of massive sprite outbreak.</div></div><div><h3>Plain language summary</h3><div>TLEs occur globally according to observation of the Imager for Sprites and Upper Atmospheric Lightning. However, reports of large-scale TLE groups in Asia were rare. This study, conducted with the contribution of Chinese sprite enthusiast, presents the important observation of Transient Luminous Events generated by a long lasting mesoscale convective system complex over Central South China. By analyzing lightning activity, weather conditions, and geographical features, this article reveals the characteristics of massive TLEs-producing thunderstorm and analyzes the meteorological reasons for the formation of the parent thunderstorms. TBB indicated the higher cloud top of parent thunderstorm than that of typical TLEs-producing MCSs in central USA. However, TLEs were largely confined to regions of TBB lower than that of regular TLEs-producing MCSs over central USA. Such distinct behavior of the parent thunderstorm is found in the delayed pre-rainy season of South China and to be attributed to a combination of intricate meteorological and topographic factors. The Subtropical High Pressure Zone, positioned farther west and north compared to previous years, led to the convergence of warm water vapor from the South China Sea and cold air from the north. The presence of the Southwest Vortex, coupled with multi-layer jets, ultimately fostered the development of intense convection.
{"title":"Observations of TLE outbreaks on consecutive nights over Central South China during the pre-rainy season in 2021","authors":"Huan Ren , Gaopeng Lu , Hailiang Huang , Liyu Wang , Yun Bi , Xiaoyang Zhang , Ziyi Wang","doi":"10.1016/j.atmosres.2025.108664","DOIUrl":"10.1016/j.atmosres.2025.108664","url":null,"abstract":"<div><div>With the contribution of Chinese sprite enthusiast, the observation of 165 Transient Luminous Events (TLEs) (almost over 98 % being sprites) over Central South China during the delayed pre-rainy season of South China on three consecutive nights of May 10th–12th, 2021 are reported. The convective cores exhibited the minimum Temperature of Black Body (TBB) of cloud top within the range of 180 to 190 K within 10 min of sprite occurrence, which extended up to or beyond the tropopause (∼ 17 km, 195 K) and was colder (more than 15 K) than that of regular TLEs-producing mesoscale convective systems (MCSs) in the central USA. However, the sprite distribution was closely associated with regions of TBB averaging 216.5 K, about 10 K warmer than that of the central USA. This distinct behavior of TLEs-producing thunderstorms in South China can be attributed to a combination of intricate meteorological and topographic factors. Firstly, in addition to the influence of the Subtropical High Pressure Zone, the positioned farther west and north compared to previous years caused the convergence of warm water vapor from the South China Sea and cold air from the north, coupled with the Southwest Vortex (SWV) and multi-layer jets, fostering intense convection. Besides, the intricate plateau and mountain topography are likely also responsible for the distinct behavior of TLEs-producing thunderstorm. Thus, more attention should be paid on thunderstorms in South China during the pre-rainy season for the future study of massive sprite outbreak.</div></div><div><h3>Plain language summary</h3><div>TLEs occur globally according to observation of the Imager for Sprites and Upper Atmospheric Lightning. However, reports of large-scale TLE groups in Asia were rare. This study, conducted with the contribution of Chinese sprite enthusiast, presents the important observation of Transient Luminous Events generated by a long lasting mesoscale convective system complex over Central South China. By analyzing lightning activity, weather conditions, and geographical features, this article reveals the characteristics of massive TLEs-producing thunderstorm and analyzes the meteorological reasons for the formation of the parent thunderstorms. TBB indicated the higher cloud top of parent thunderstorm than that of typical TLEs-producing MCSs in central USA. However, TLEs were largely confined to regions of TBB lower than that of regular TLEs-producing MCSs over central USA. Such distinct behavior of the parent thunderstorm is found in the delayed pre-rainy season of South China and to be attributed to a combination of intricate meteorological and topographic factors. The Subtropical High Pressure Zone, positioned farther west and north compared to previous years, led to the convergence of warm water vapor from the South China Sea and cold air from the north. The presence of the Southwest Vortex, coupled with multi-layer jets, ultimately fostered the development of intense convection.","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"331 ","pages":"Article 108664"},"PeriodicalIF":4.4,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145613783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-11-26DOI: 10.1016/j.atmosres.2025.108644
Kairan Wang , Wenrui Zhang , Chao Gao , Hu Liu , Wenhao Gao , Mingyuan Fan , Zhiming Han
Drought is a complex extreme climate event that typically originates from anomalous atmospheric precipitation and progressively propagates through hydrological, agricultural, and ecological systems, subsequently causing more severe impacts. Therefore, elucidating the propagation mechanisms among different types of droughts is crucial for enhancing drought early warning capabilities and achieving coordinated regulation across multiple systems. This study focuses on the Yellow River Basin (YRB) as the research area and, based on a multi-source dataset spanning 1982–2018, systematically investigates the propagation characteristics and spatiotemporal structure of meteorological drought to hydrological, agricultural, and ecological droughts from the perspective of drought events. This is achieved through the integrated application of run theory and an optimized drought migration model. The results indicate that in the YRB, the propagation time of droughts shows that hydrological drought occurs earlier than agricultural and ecological droughts. The drought propagation process in the YRB exhibits two typical patterns: a “high-frequency and fast-response” type and a “low-frequency and slow-response” type, corresponding respectively to regions with strong meteorological forcing and human activities. The three-dimensional spatiotemporal propagation pathways of typical years further reveal that meteorological droughts in the YRB occur frequently and expand rapidly. The hydrological droughts exhibit strong accumulation and persistence, with a response process markedly more pronounced than that of agricultural and ecological droughts, displaying significant regional disparities. The findings contribute to a deeper understanding of the propagation mechanisms among multiple drought types and provide a theoretical foundation and technical support for developing hierarchical early warning and coordinated response systems tailored to different sectors.
{"title":"Spatiotemporal evolution characteristics of multi-type drought propagation processes in the Yellow River Basin, China","authors":"Kairan Wang , Wenrui Zhang , Chao Gao , Hu Liu , Wenhao Gao , Mingyuan Fan , Zhiming Han","doi":"10.1016/j.atmosres.2025.108644","DOIUrl":"10.1016/j.atmosres.2025.108644","url":null,"abstract":"<div><div>Drought is a complex extreme climate event that typically originates from anomalous atmospheric precipitation and progressively propagates through hydrological, agricultural, and ecological systems, subsequently causing more severe impacts. Therefore, elucidating the propagation mechanisms among different types of droughts is crucial for enhancing drought early warning capabilities and achieving coordinated regulation across multiple systems. This study focuses on the Yellow River Basin (YRB) as the research area and, based on a multi-source dataset spanning 1982–2018, systematically investigates the propagation characteristics and spatiotemporal structure of meteorological drought to hydrological, agricultural, and ecological droughts from the perspective of drought events. This is achieved through the integrated application of run theory and an optimized drought migration model. The results indicate that in the YRB, the propagation time of droughts shows that hydrological drought occurs earlier than agricultural and ecological droughts. The drought propagation process in the YRB exhibits two typical patterns: a “high-frequency and fast-response” type and a “low-frequency and slow-response” type, corresponding respectively to regions with strong meteorological forcing and human activities. The three-dimensional spatiotemporal propagation pathways of typical years further reveal that meteorological droughts in the YRB occur frequently and expand rapidly. The hydrological droughts exhibit strong accumulation and persistence, with a response process markedly more pronounced than that of agricultural and ecological droughts, displaying significant regional disparities. The findings contribute to a deeper understanding of the propagation mechanisms among multiple drought types and provide a theoretical foundation and technical support for developing hierarchical early warning and coordinated response systems tailored to different sectors.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"331 ","pages":"Article 108644"},"PeriodicalIF":4.4,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145609518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-11-24DOI: 10.1016/j.atmosres.2025.108652
Qian Zhang , Xudong Wang , Yuan Long
An increase in black carbon (BC) column concentration intensifies atmospheric warming, alters precipitation regimes, and accelerates glacial melting, posing substantial risks to regional climates and ecosystems. This study systematically evaluated the applicability of MERRA-2 reanalysis data over China by using daily-scale BC column concentration observations from AERONET sites. By integrating multi-source remote sensing data with machine learning models, a high-precision BC column concentration dataset for China was reconstructed. The results show that MERRA-2 data exhibit significant limitations in the China region, with an overall correlation coefficient (R) of only 0.54, an RMSE of 6701 μg/m2, and only 41 % of the sites demonstrating high correlation. For the high-quality data, R is 0.44, with an RMSE as high as 9112 μg/m2; the poorest performance is observed in the medium and low-quality data, with an R of 0.21. In contrast, the constructed model increased R by 0.29 and decreased RMSE by 2396 μg/m2 across the entire dataset, with the number of sites showing good correlation improving by 34 %. For the high and medium-quality data, R ranged from 0.70 to 0.86, and the RMSE decreased by 1475—4569 μg/m2. In addition, MERRA-2 BCE column concentration and BC aerosol optical depth are the key factors in the model, while surface-level PM2.5, organic matter, and BC concentrations are also important variables. Spatiotemporal evolution analysis shows a high degree of spatial overlap between regions with elevated BC column concentrations and China's key national urban agglomerations as well as major energy corridors. From 2001 to 2023, the national BC column concentration exhibited a trend of initial increase followed by a steady decline, with an average annual decrease of 42.36 μg/m2. Significant emission reduction achievements were observed in the central and eastern regions, while high concentrations persist in the western region. This study provides a critical data and technical foundation for both regional climate research and atmospheric environmental governance.
{"title":"Assessing and improving MERRA-2 black carbon column concentration over china using multi-source data and machine learning","authors":"Qian Zhang , Xudong Wang , Yuan Long","doi":"10.1016/j.atmosres.2025.108652","DOIUrl":"10.1016/j.atmosres.2025.108652","url":null,"abstract":"<div><div>An increase in black carbon (BC) column concentration intensifies atmospheric warming, alters precipitation regimes, and accelerates glacial melting, posing substantial risks to regional climates and ecosystems. This study systematically evaluated the applicability of MERRA-2 reanalysis data over China by using daily-scale BC column concentration observations from AERONET sites. By integrating multi-source remote sensing data with machine learning models, a high-precision BC column concentration dataset for China was reconstructed. The results show that MERRA-2 data exhibit significant limitations in the China region, with an overall correlation coefficient (R) of only 0.54, an RMSE of 6701 μg/m<sup>2</sup>, and only 41 % of the sites demonstrating high correlation. For the high-quality data, R is 0.44, with an RMSE as high as 9112 μg/m<sup>2</sup>; the poorest performance is observed in the medium and low-quality data, with an R of 0.21. In contrast, the constructed model increased R by 0.29 and decreased RMSE by 2396 μg/m<sup>2</sup> across the entire dataset, with the number of sites showing good correlation improving by 34 %. For the high and medium-quality data, R ranged from 0.70 to 0.86, and the RMSE decreased by 1475—4569 μg/m<sup>2</sup>. In addition, MERRA-2 BCE column concentration and BC aerosol optical depth are the key factors in the model, while surface-level PM<sub>2.5</sub>, organic matter, and BC concentrations are also important variables. Spatiotemporal evolution analysis shows a high degree of spatial overlap between regions with elevated BC column concentrations and China's key national urban agglomerations as well as major energy corridors. From 2001 to 2023, the national BC column concentration exhibited a trend of initial increase followed by a steady decline, with an average annual decrease of 42.36 μg/m<sup>2</sup>. Significant emission reduction achievements were observed in the central and eastern regions, while high concentrations persist in the western region. This study provides a critical data and technical foundation for both regional climate research and atmospheric environmental governance.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"331 ","pages":"Article 108652"},"PeriodicalIF":4.4,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145593688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-11-24DOI: 10.1016/j.atmosres.2025.108640
Xuan Liu , Zhanfang Hou , Qizong Wang , Chen Chen , Jierui Hou , Weibo Li , Xiaodi Liu , Jianjun Li , Jingjing Meng
Dicarboxylic acids (diacids) and related species act as critical molecular tracers for secondary organic aerosols (SOA), which significantly influence atmospheric chemical processes and climate forcing. Nevertheless, the origins and formation pathways of these compounds remain inadequately characterized, introducing considerable uncertainties in evaluating the climate effects of SOA. This study investigates the seasonal variability in molecular distribution and stable carbon isotopic compositions (δ13C) of diacid homologs in PM2.5 to elucidate their origins and formation mechanisms in an urban Liaocheng, China. Elevated concentrations of diacid homologs were observed in winter (1469 ± 1325 ng m−3) than in summer (884 ± 343 ng m−3), predominantly attributed to significant contributions from fossil fuel combustion and biomass burning for heating during cold months. In contrast, summertime aerosols exhibited stronger photochemical aging, evidenced by enriched δ13C values of oxalic acid (C2) and increased ratios of C2/succinic acid (C4), malonic acid (C3)/C4, and C2/diacids. Correlation analyses and positive matrix factorization identified gaseous photochemical oxidation (52.4 %) as the dominant formation pathway driven by O3 and solar radiation in summer, while aqueous oxidation (57.6 %) modulated by relative humidity, aerosol acidity, and liquid water content prevailed in winter. A consistent decrease in δ13C values with increasing carbon chain length aligns with kinetic isotope effects (KIEs) during oxidative processes. Inter-site comparisons reveal that urban sites exhibit the most depleted δ13C values in C2 due to dominant anthropogenic emissions, whereas less depleted values at rural and background sites reflect greater biogenic contributions and extensive photochemical aging. Strong correlations between δ13C values of C2 and the C2/diacids ratio (R2 ≥ 0.55) further support the use of δ13C as an effective proxy for organic aerosol aging. These findings underscore the necessity of adopting a balanced and coordinated approach to air pollution control, which must address both primary emissions and secondary formation processes, while considering the interplay with meteorological factors.
二羧酸及其相关物质是二次有机气溶胶（SOA）的关键分子示踪剂，对大气化学过程和气候强迫具有重要影响。然而，这些化合物的起源和形成途径仍然没有得到充分的表征，在评估SOA的气候影响时引入了相当大的不确定性。本文研究了聊城市PM2.5中二酸同源物的分子分布和稳定碳同位素组成（δ13C）的季节变化，以阐明其来源和形成机制。二酸同源物浓度在冬季（1469±1325 ng m - 3）高于夏季（884±343 ng m - 3），这主要归因于化石燃料燃烧和在寒冷月份取暖时燃烧生物质。夏季气溶胶表现出较强的光化学老化，草酸(C2) δ13C值增加，C2/琥珀酸（C4）、丙二酸(C3)/C4和C2/二酸的比值增加。相关分析和正矩阵分解发现，夏季臭氧和太阳辐射驱动的气体光化学氧化（52.4%）是主要的形成途径，而冬季受相对湿度、气溶胶酸度和液态水含量调节的水氧化（57.6%）占主导地位。δ13C值随碳链长度的增加而持续下降，这与氧化过程中的动力学同位素效应（KIEs）一致。站点间比较表明，由于人为排放的主导，城市站点的δ13C值消耗最多，而农村和背景站点的δ13C值消耗较少，反映了更大的生物成因贡献和广泛的光化学老化。C2的δ13C值与C2/二酸比之间的强相关性（R2≥0.55）进一步支持δ13C作为有机气溶胶老化的有效代理。这些发现强调了采取平衡和协调的方法来控制空气污染的必要性，这种方法必须同时处理初级排放和次级形成过程，同时考虑与气象因素的相互作用。
{"title":"Seasonal characteristics and 13C isotopic composition of dicarboxylic acid homologs in the urban atmosphere: Implications for provenance and aging processes","authors":"Xuan Liu , Zhanfang Hou , Qizong Wang , Chen Chen , Jierui Hou , Weibo Li , Xiaodi Liu , Jianjun Li , Jingjing Meng","doi":"10.1016/j.atmosres.2025.108640","DOIUrl":"10.1016/j.atmosres.2025.108640","url":null,"abstract":"<div><div>Dicarboxylic acids (diacids) and related species act as critical molecular tracers for secondary organic aerosols (SOA), which significantly influence atmospheric chemical processes and climate forcing. Nevertheless, the origins and formation pathways of these compounds remain inadequately characterized, introducing considerable uncertainties in evaluating the climate effects of SOA. This study investigates the seasonal variability in molecular distribution and stable carbon isotopic compositions (δ<sup>13</sup>C) of diacid homologs in PM<sub>2.5</sub> to elucidate their origins and formation mechanisms in an urban Liaocheng, China. Elevated concentrations of diacid homologs were observed in winter (1469 ± 1325 ng m<sup>−3</sup>) than in summer (884 ± 343 ng m<sup>−3</sup>), predominantly attributed to significant contributions from fossil fuel combustion and biomass burning for heating during cold months. In contrast, summertime aerosols exhibited stronger photochemical aging, evidenced by enriched δ<sup>13</sup>C values of oxalic acid (C<sub>2</sub>) and increased ratios of C<sub>2</sub>/succinic acid (C<sub>4</sub>), malonic acid (C<sub>3</sub>)/C<sub>4</sub>, and C<sub>2</sub>/diacids. Correlation analyses and positive matrix factorization identified gaseous photochemical oxidation (52.4 %) as the dominant formation pathway driven by O<sub>3</sub> and solar radiation in summer, while aqueous oxidation (57.6 %) modulated by relative humidity, aerosol acidity, and liquid water content prevailed in winter. A consistent decrease in δ<sup>13</sup>C values with increasing carbon chain length aligns with kinetic isotope effects (KIEs) during oxidative processes. Inter-site comparisons reveal that urban sites exhibit the most depleted δ<sup>13</sup>C values in C<sub>2</sub> due to dominant anthropogenic emissions, whereas less depleted values at rural and background sites reflect greater biogenic contributions and extensive photochemical aging. Strong correlations between δ<sup>13</sup>C values of C<sub>2</sub> and the C<sub>2</sub>/diacids ratio (R<sup>2</sup> ≥ 0.55) further support the use of δ<sup>13</sup>C as an effective proxy for organic aerosol aging. These findings underscore the necessity of adopting a balanced and coordinated approach to air pollution control, which must address both primary emissions and secondary formation processes, while considering the interplay with meteorological factors.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"331 ","pages":"Article 108640"},"PeriodicalIF":4.4,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145593691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-11-24DOI: 10.1016/j.atmosres.2025.108653
Dongmei Xu , Liu Yi , Jingyao Luo , Zhixin He , Yakai Guo , Feifei Shen
This study leverages the Weather Research and Forecasting (WRF) model, integrated with the three-dimensional variational (3DVAR) data assimilation system, to conduct a high-resolution simulation of a thunderstorm gale event in Beijing. By assimilating observations from Automatic Weather Stations (AWSs), the impact of different observation errors is systematically assessed and explored. This study demonstrates that varying observation errors significantly influence the performance of the wind analysis and forecast. Mitigating observation errors in cases with significant observation-minus-background (OMB) discrepancies enhances the reliability of observations with large departures from the background, resulting in greater analysis increments and improved agreement with the assimilated observations. In contrast, the Desroziers method computes observation error covariances through statistical analysis of OMB and observation-minus-analysis (OMA) residuals. This approach systematically assigns higher error estimates, enabling the assimilation of more observations with reduced weights while enhancing spatial continuity in the analysis. Both experiments employing modified observation error parameters demonstrated superior predictive accuracy compared to the default configuration, enabling more precise identification of strong wind regions while mitigating overestimation tendencies. Statistical metrics (BIAS, RMSE) and FSS scores confirm their superior performance, particularly in extreme wind speed forecasting, with Exp_D05 outperforming all other experiments. These findings highlight the importance of optimized observation error estimates in AWSs data assimilation for improved wind analysis and forecasting.
{"title":"Assessment of observation errors in AWS data assimilation: Application to a thunderstorm gale event forecast","authors":"Dongmei Xu , Liu Yi , Jingyao Luo , Zhixin He , Yakai Guo , Feifei Shen","doi":"10.1016/j.atmosres.2025.108653","DOIUrl":"10.1016/j.atmosres.2025.108653","url":null,"abstract":"<div><div>This study leverages the Weather Research and Forecasting (WRF) model, integrated with the three-dimensional variational (3DVAR) data assimilation system, to conduct a high-resolution simulation of a thunderstorm gale event in Beijing. By assimilating observations from Automatic Weather Stations (AWSs), the impact of different observation errors is systematically assessed and explored. This study demonstrates that varying observation errors significantly influence the performance of the wind analysis and forecast. Mitigating observation errors in cases with significant observation-minus-background (OMB) discrepancies enhances the reliability of observations with large departures from the background, resulting in greater analysis increments and improved agreement with the assimilated observations. In contrast, the Desroziers method computes observation error covariances through statistical analysis of OMB and observation-minus-analysis (OMA) residuals. This approach systematically assigns higher error estimates, enabling the assimilation of more observations with reduced weights while enhancing spatial continuity in the analysis. Both experiments employing modified observation error parameters demonstrated superior predictive accuracy compared to the default configuration, enabling more precise identification of strong wind regions while mitigating overestimation tendencies. Statistical metrics (BIAS, RMSE) and FSS scores confirm their superior performance, particularly in extreme wind speed forecasting, with Exp_D05 outperforming all other experiments. These findings highlight the importance of optimized observation error estimates in AWSs data assimilation for improved wind analysis and forecasting.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"331 ","pages":"Article 108653"},"PeriodicalIF":4.4,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145593696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
On April 16th, 2024, Dubai experienced a record-breaking extreme rainfall event, with a total precipitation of 132.21 mm, accounting for 95.83 % of the month's total rainfall. The precipitation rate on April 16th was 128.86 mm/day, reflecting the abruptness of this event. This study defined the “Chimney effect” with this heavy rainfall. Using moisture budget analysis, the primary driver for this event was the anomalous vertical convection (7.46 mm/day), which was mainly contributed by the anomalous updrafts (exceeding 1.5 Pa/s). Conversely, the climatological zonal convection (−7.07 mm/day) had the largest inhibiting impact on rainfall. The anomalous signal of atmospheric circulation was 8 days earlier than this heavy rainfall, which was initially identified on April 8th with anomalous westerlies to the south of Dubai. This consistent phenomenon was accompanied by an anomalous northerlies on the 14th, resulting in a low pressure center over Dubai on the 16th, with a low-level convergence and upper-level divergence character. The increase of sea surface temperature in the northern Indian Ocean facilitated the transfer of moisture to Dubai. The presence of robust updrafts from 1000 to 200 hPa over Dubai on the 16th, shaped by an intense low pressure system, resulted in the lifting and cooling of warm and humid air from the Indian Ocean, culminating in heavy rainfall. While this event highlights the impact of climate change on arid regions, the study emphasizes the need to improve the resilience of infrastructure, particularly in light of the increasing frequency and intensity of extreme weather events.
{"title":"Causes of an extreme rainfall in Dubai on April 16th, 2024","authors":"Baoxu Chen , Hongyan Cui , Ziqun Zhang , Fangli Qiao , Xiaohui Sun , Chang Gao , Xinyu Meng , Changshui Xia","doi":"10.1016/j.atmosres.2025.108651","DOIUrl":"10.1016/j.atmosres.2025.108651","url":null,"abstract":"<div><div>On April 16th, 2024, Dubai experienced a record-breaking extreme rainfall event, with a total precipitation of 132.21 mm, accounting for 95.83 % of the month's total rainfall. The precipitation rate on April 16th was 128.86 mm/day, reflecting the abruptness of this event. This study defined the “Chimney effect” with this heavy rainfall. Using moisture budget analysis, the primary driver for this event was the anomalous vertical convection (7.46 mm/day), which was mainly contributed by the anomalous updrafts (exceeding 1.5 Pa/s). Conversely, the climatological zonal convection (−7.07 mm/day) had the largest inhibiting impact on rainfall. The anomalous signal of atmospheric circulation was 8 days earlier than this heavy rainfall, which was initially identified on April 8th with anomalous westerlies to the south of Dubai. This consistent phenomenon was accompanied by an anomalous northerlies on the 14th, resulting in a low pressure center over Dubai on the 16th, with a low-level convergence and upper-level divergence character. The increase of sea surface temperature in the northern Indian Ocean facilitated the transfer of moisture to Dubai. The presence of robust updrafts from 1000 to 200 hPa over Dubai on the 16th, shaped by an intense low pressure system, resulted in the lifting and cooling of warm and humid air from the Indian Ocean, culminating in heavy rainfall. While this event highlights the impact of climate change on arid regions, the study emphasizes the need to improve the resilience of infrastructure, particularly in light of the increasing frequency and intensity of extreme weather events.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"331 ","pages":"Article 108651"},"PeriodicalIF":4.4,"publicationDate":"2025-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145575311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-11-22DOI: 10.1016/j.atmosres.2025.108625
Meihua Wang , Lei Liu , Hailing Xie , Hao Zhou , Jing Su , Xuejin Sun , Shuai Hu , Bida Jian
With rapid climate warming, Arctic surface temperatures have increased by 1.2 °C per decade over recent decades. Meteorological factors influence surface temperature by perturbing the Arctic surface radiation (ASR) budget, yet the changing thermodynamic and dynamic processes driving the ASR budget remain poorly understood. Based on CERES observations from 2001 to 2020, this study quantified the contribution rates of different drivers to the long-term changes in the ASR budget using the stepwise multiple liner regression models. We found that Arctic surface net shortwave (SW) and longwave (LW) radiation show a positive trend of 2.8 and 2.9 W m−2/decade, respectively. Attribution analysis reveals that such trends of the ASR tightly relate to the changes in climatic factors, but their temporal relationships exhibit regional divergence. Over land and sea ice, cloud fraction dominantly contributes 46 % and 50 % of the variations in net SW flux anomalies, respectively, and 65 % and 40 % of the variations in net LW flux anomalies. Over open ocean, cloud optical thickness explains 49 % of the changes in net SW flux anomalies, and water vapor contributes 35 % of the variations in net LW flux anomalies. Across the most Arctic regions, clouds induce a net warming effects on the ground, particularly pronounced impacts in central Greenland where the cloud-induced radiative effects exceed 40 W m−2. Notably, contrary to conventional SW cooling expectations, peripheral Greenland exhibits cloud-induced SW warming. These findings provide critical insights for refining polar radiation parameterizations in climate models.
随着气候迅速变暖，近几十年来，北极地表温度每十年上升1.2°C。气象因子通过干扰北极地表辐射收支来影响地表温度，但驱动地表辐射收支的热力学和动力学过程的变化仍然知之甚少。基于2001 - 2020年的CERES观测数据，采用逐步多元线性回归模型量化了不同驱动因素对ASR预算长期变化的贡献率。研究发现，北极地表净短波（SW）和长波（LW）辐射分别呈2.8和2.9 W m−2/ 10年的正趋势。归因分析表明，ASR的变化趋势与气候因子的变化密切相关，但其时间关系表现出区域差异。在陆地和海冰上，云分数分别占净西南偏南通量异常变化的46%和50%，占净低地偏南通量异常变化的65%和40%。在公海上，云光学厚度解释了49%的净西南偏南通量异常变化，水蒸气解释了35%的净LW通量异常变化。在大多数北极地区，云对地面产生净变暖效应，在格陵兰岛中部的影响尤其明显，云引起的辐射效应超过40 W m - 2。值得注意的是，与传统的西南偏南变冷预期相反，格陵兰岛外围表现出云引起的西南偏南变暖。这些发现为改进气候模式中的极地辐射参数化提供了重要的见解。
{"title":"Quantifying the impacts of key meteorological drivers on the Arctic surface radiation budget","authors":"Meihua Wang , Lei Liu , Hailing Xie , Hao Zhou , Jing Su , Xuejin Sun , Shuai Hu , Bida Jian","doi":"10.1016/j.atmosres.2025.108625","DOIUrl":"10.1016/j.atmosres.2025.108625","url":null,"abstract":"<div><div>With rapid climate warming, Arctic surface temperatures have increased by 1.2 °C per decade over recent decades. Meteorological factors influence surface temperature by perturbing the Arctic surface radiation (ASR) budget, yet the changing thermodynamic and dynamic processes driving the ASR budget remain poorly understood. Based on CERES observations from 2001 to 2020, this study quantified the contribution rates of different drivers to the long-term changes in the ASR budget using the stepwise multiple liner regression models. We found that Arctic surface net shortwave (SW) and longwave (LW) radiation show a positive trend of 2.8 and 2.9 W m<sup>−2</sup>/decade, respectively. Attribution analysis reveals that such trends of the ASR tightly relate to the changes in climatic factors, but their temporal relationships exhibit regional divergence. Over land and sea ice, cloud fraction dominantly contributes 46 % and 50 % of the variations in net SW flux anomalies, respectively, and 65 % and 40 % of the variations in net LW flux anomalies. Over open ocean, cloud optical thickness explains 49 % of the changes in net SW flux anomalies, and water vapor contributes 35 % of the variations in net LW flux anomalies. Across the most Arctic regions, clouds induce a net warming effects on the ground, particularly pronounced impacts in central Greenland where the cloud-induced radiative effects exceed 40 W m<sup>−2</sup>. Notably, contrary to conventional SW cooling expectations, peripheral Greenland exhibits cloud-induced SW warming. These findings provide critical insights for refining polar radiation parameterizations in climate models.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"331 ","pages":"Article 108625"},"PeriodicalIF":4.4,"publicationDate":"2025-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145567639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-11-22DOI: 10.1016/j.atmosres.2025.108649
Bida Jian , Zhanshan Ma , Qijun Liu , Zhe Li , Liantang Deng , Haohao Nie , Chong Liu , Chuanfeng Zhao , Jian Sun , Xueshun Shen
This study develops an advanced cloud microphysics scheme based on the LiuMa cloud microphysics scheme, which explicitly incorporates aerosol-cloud interaction (ACI) parameterizations, allowing for a detailed investigation of the effects of aerosols on cloud microphysical and precipitation processes. The new scheme was employed into the CMA-MESO V5.0 regional model, and a simulation of severe convective precipitation case in the HuaBei region was carried out to assess the impact of aerosol concentration on hydrometeor mixing ratio, microphysical conversion rates, and precipitation formation within both warm and cold cloud processes. Aerosol sensitivity experiments (clean, control, polluted scenarios) reveal that higher aerosol concentrations (polluted) enhance light rain and extreme heavy rain but reduce moderate/heavy rain. The clean experiment shows greater spatiotemporal variability in heavy precipitation compared to control experiment, indicating the aerosol significantly modulate the spatio-temporal distribution of precipitation. Microphysical budget analysis reveals that higher aerosol concentration enhances cloud droplet concentration while suppressing warm rain processes such as autoconversion and collision-coalescence. In ice-phase processes, aerosols reduce cloud water freezing and riming accretion efficiency, particularly affecting graupel development and subsequent melting, thereby weakening surface precipitation. Batch simulations of 57 precipitation events (June–August 2018) demonstrate that the aerosol-aware LiuMa scheme improves the threat scores (TS) and equitable threat scores (ETS) of forecast performance for extreme (>50 mm, ΔTS: +14.9 %, ΔETS: +15.6 %) precipitation in the CMA-MESO model. Notably, the TS (ETS) for extreme precipitation increases by 24.6 % (26.0 %) under polluted conditions (a total of 19 precipitation events). These results indicate the crucial role of ACI parameterization in enhancing the accuracy of heavy rainfall forecasts.
{"title":"An advanced double-moment cloud microphysics scheme with explicit aerosol-cloud interactions and its performance in quantitative precipitation forecasting (QPF) in the CMA-MESO V5.0","authors":"Bida Jian , Zhanshan Ma , Qijun Liu , Zhe Li , Liantang Deng , Haohao Nie , Chong Liu , Chuanfeng Zhao , Jian Sun , Xueshun Shen","doi":"10.1016/j.atmosres.2025.108649","DOIUrl":"10.1016/j.atmosres.2025.108649","url":null,"abstract":"<div><div>This study develops an advanced cloud microphysics scheme based on the LiuMa cloud microphysics scheme, which explicitly incorporates aerosol-cloud interaction (ACI) parameterizations, allowing for a detailed investigation of the effects of aerosols on cloud microphysical and precipitation processes. The new scheme was employed into the CMA-MESO V5.0 regional model, and a simulation of severe convective precipitation case in the HuaBei region was carried out to assess the impact of aerosol concentration on hydrometeor mixing ratio, microphysical conversion rates, and precipitation formation within both warm and cold cloud processes. Aerosol sensitivity experiments (clean, control, polluted scenarios) reveal that higher aerosol concentrations (polluted) enhance light rain and extreme heavy rain but reduce moderate/heavy rain. The clean experiment shows greater spatiotemporal variability in heavy precipitation compared to control experiment, indicating the aerosol significantly modulate the spatio-temporal distribution of precipitation. Microphysical budget analysis reveals that higher aerosol concentration enhances cloud droplet concentration while suppressing warm rain processes such as autoconversion and collision-coalescence. In ice-phase processes, aerosols reduce cloud water freezing and riming accretion efficiency, particularly affecting graupel development and subsequent melting, thereby weakening surface precipitation. Batch simulations of 57 precipitation events (June–August 2018) demonstrate that the aerosol-aware LiuMa scheme improves the threat scores (TS) and equitable threat scores (ETS) of forecast performance for extreme (>50 mm, ΔTS: +14.9 %, ΔETS: +15.6 %) precipitation in the CMA-MESO model. Notably, the TS (ETS) for extreme precipitation increases by 24.6 % (26.0 %) under polluted conditions (a total of 19 precipitation events). These results indicate the crucial role of ACI parameterization in enhancing the accuracy of heavy rainfall forecasts.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"331 ","pages":"Article 108649"},"PeriodicalIF":4.4,"publicationDate":"2025-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145575314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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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