Pub Date : 2025-02-18DOI: 10.1016/j.atmosres.2025.108007
Boyuan Zhang , Yongli He , Xiaodan Guan
Coastal heatwaves, which often coincide with typhoons, extreme sea levels, and other compound extreme events under global warming, are more complex and less studied compared to inland and marine heatwaves. In this study, a three-dimensional connected algorithm was used to detect spatiotemporal heatwave events during the summer seasons from 1959 to 2023 on a global scale. A novel method was developed to distinguish between land and coastal heatwaves by considering the movement of heatwaves during their lifecycle. Both land and coastal heatwaves increase in frequency and projection area but decrease in maximum intensity, with coastal heatwaves exhibiting a higher growth rate than land heatwaves. Across the Northern Hemisphere, metrics for both heatwave types demonstrate consistent upward trends. However, the Southern Hemisphere presents divergent patterns, with land heatwaves exhibiting a decreasing trend while coastal heatwaves continue to intensify. To assess the impacts of heatwave on human health, the heat stress index was analyzed during heatwave periods. The results indicate that heat stress conditions, currently classified under caution categories, are likely to escalate into more dangerous levels under global warming. This study provides critical insights into the different responses of land and coastal heatwaves to global warming and underscores the urgency of formulating effective disaster prevention strategies to mitigate their societal and environmental impacts.
{"title":"Increasing trends of land and coastal heatwaves under global warming","authors":"Boyuan Zhang , Yongli He , Xiaodan Guan","doi":"10.1016/j.atmosres.2025.108007","DOIUrl":"10.1016/j.atmosres.2025.108007","url":null,"abstract":"<div><div>Coastal heatwaves, which often coincide with typhoons, extreme sea levels, and other compound extreme events under global warming, are more complex and less studied compared to inland and marine heatwaves. In this study, a three-dimensional connected algorithm was used to detect spatiotemporal heatwave events during the summer seasons from 1959 to 2023 on a global scale. A novel method was developed to distinguish between land and coastal heatwaves by considering the movement of heatwaves during their lifecycle. Both land and coastal heatwaves increase in frequency and projection area but decrease in maximum intensity, with coastal heatwaves exhibiting a higher growth rate than land heatwaves. Across the Northern Hemisphere, metrics for both heatwave types demonstrate consistent upward trends. However, the Southern Hemisphere presents divergent patterns, with land heatwaves exhibiting a decreasing trend while coastal heatwaves continue to intensify. To assess the impacts of heatwave on human health, the heat stress index was analyzed during heatwave periods. The results indicate that heat stress conditions, currently classified under caution categories, are likely to escalate into more dangerous levels under global warming. This study provides critical insights into the different responses of land and coastal heatwaves to global warming and underscores the urgency of formulating effective disaster prevention strategies to mitigate their societal and environmental impacts.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"318 ","pages":"Article 108007"},"PeriodicalIF":4.5,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143474801","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 : 2025-02-17DOI: 10.1016/j.atmosres.2025.107998
O.N. Toptunova , M.A. Motsakov , A.V. Koval , T.S. Ermakova , K.A. Didenko
The present study is concerned with the aspects of stratosphere-troposphere dynamic interaction during major sudden stratospheric warming (SSW). The SSW observed in December 2018 – January 2019 was taken for consideration. The influence of the stratospheric polar vortex location on the position of the upper-level frontal zone (UFZ), changes in the steering flows in the middle troposphere, surface temperature anomalies, as well as on the characteristics of the tropopause have been studied using MERRA2 reanalysis data. Analysis has revealed that SSW events influence the location of the upper-level frontal zone (UFZ), subsequently altering steering flows in the troposphere and leading to the development of surface cold waves. Isentropic analysis have shown that SSW caused the intrusion of stratospheric air into the troposphere, which contributed to the intensification of the cold wave. Correlation analysis have demonstrated a statistically significant relationship between stratospheric processes and anomalies of geopotential height in the middle troposphere (500 hPa), exhibiting a two-week time lag following SSW events. Spatial distribution of the maximum correlation coefficient corresponds to the region with the UFZ deformation. In the cross-time interval of the formation of the SSW, 3-dimensional fluxes of planetary wave activity have been calculated. The enhanced reflection of wave activity over Canada during the SSW demonstrated the dynamic influence of the stratosphere on the troposphere, contributing to the formation of the cold wave.
This confirms the role of stratospheric-tropospheric coupling in surface weather extremes.
{"title":"Impact of sudden stratospheric warming on tropospheric circulation and a cold wave formation: The case of the January 2019 event","authors":"O.N. Toptunova , M.A. Motsakov , A.V. Koval , T.S. Ermakova , K.A. Didenko","doi":"10.1016/j.atmosres.2025.107998","DOIUrl":"10.1016/j.atmosres.2025.107998","url":null,"abstract":"<div><div>The present study is concerned with the aspects of stratosphere-troposphere dynamic interaction during major sudden stratospheric warming (SSW). The SSW observed in December 2018 – January 2019 was taken for consideration. The influence of the stratospheric polar vortex location on the position of the upper-level frontal zone (UFZ), changes in the steering flows in the middle troposphere, surface temperature anomalies, as well as on the characteristics of the tropopause have been studied using MERRA2 reanalysis data. Analysis has revealed that SSW events influence the location of the upper-level frontal zone (UFZ), subsequently altering steering flows in the troposphere and leading to the development of surface cold waves. Isentropic analysis have shown that SSW caused the intrusion of stratospheric air into the troposphere, which contributed to the intensification of the cold wave. Correlation analysis have demonstrated a statistically significant relationship between stratospheric processes and anomalies of geopotential height in the middle troposphere (500 hPa), exhibiting a two-week time lag following SSW events. Spatial distribution of the maximum correlation coefficient corresponds to the region with the UFZ deformation. In the cross-time interval of the formation of the SSW, 3-dimensional fluxes of planetary wave activity have been calculated. The enhanced reflection of wave activity over Canada during the SSW demonstrated the dynamic influence of the stratosphere on the troposphere, contributing to the formation of the cold wave.</div><div>This confirms the role of stratospheric-tropospheric coupling in surface weather extremes.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"318 ","pages":"Article 107998"},"PeriodicalIF":4.5,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509552","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 : 2025-02-17DOI: 10.1016/j.atmosres.2025.107986
DanChen Yan , TianYu Zhang , LengJian Chen , Cheng Chi , JianYang , ZiJing Ou
In this paper, based on the observation data of sea surface buoys, 17 tropical cyclones (TCs) occurring in the East China Sea and South China Sea from 2017 to 2021 are synthesized to conduct a force analysis in a two-dimensional radial momentum equation. The analysis evaluates the magnitude, equilibrium, proportional relationships, and spatial distribution features of each force, leading to clarified universal laws. The findings reveal a pronounced radial variability feature in the mean TC sea surface structure. Notably, the regions where the changes are most dramatic are located approximately 80 km from the mean TC center and particularly at 20–40 km. Within an overall range of 0–400 km, the cumulative contributions of each force from high to low are the pressure gradient force, friction term, centrifugal force, Coriolis force and acceleration force. In addition, obvious anisotropic features are also observed. The four orientations can be arranged according to force strength as the right region (240–300°), left region (60–120°), rear region (150–210°) and front region (0–30° and 330–360°). The pronounced pressure gradient force is extremely unstable within the 250 km range of the right (240–300°) and 200 km range of the left (60–120°) regions of the mean TC. The sensitivity of the centrifugal force to radial changes surpasses that of azimuthal changes, and significant variations are concentrated within a radial distance of 50 km. For the Coriolis force, noticeable anisotropic features are evident within the 150 km radius of the 210–330° sector. Additionally, a comparison of the observed radial pressure profile with empirical pressure models was conducted. We found that B parameter values between 0.7 and 1.0 are optimal for our observational cases. Selecting an appropriate environmental pressure can bring the empirical model closer to the observed data. This study establishes a realistic foundation for enhancing existing sea surface parametric wind models of TCs and developing novel approaches, thereby ultimately improving the numerical calculation accuracy for storm surges and other air–sea interactions.
{"title":"Observational force analysis and anisotropic characteristics of tropical cyclone sea surface wind fields over Chinese offshore areas","authors":"DanChen Yan , TianYu Zhang , LengJian Chen , Cheng Chi , JianYang , ZiJing Ou","doi":"10.1016/j.atmosres.2025.107986","DOIUrl":"10.1016/j.atmosres.2025.107986","url":null,"abstract":"<div><div>In this paper, based on the observation data of sea surface buoys, 17 tropical cyclones (TCs) occurring in the East China Sea and South China Sea from 2017 to 2021 are synthesized to conduct a force analysis in a two-dimensional radial momentum equation. The analysis evaluates the magnitude, equilibrium, proportional relationships, and spatial distribution features of each force, leading to clarified universal laws. The findings reveal a pronounced radial variability feature in the mean TC sea surface structure. Notably, the regions where the changes are most dramatic are located approximately 80 km from the mean TC center and particularly at 20–40 km. Within an overall range of 0–400 km, the cumulative contributions of each force from high to low are the pressure gradient force, friction term, centrifugal force, Coriolis force and acceleration force. In addition, obvious anisotropic features are also observed. The four orientations can be arranged according to force strength as the right region (240–300°), left region (60–120°), rear region (150–210°) and front region (0–30° and 330–360°). The pronounced pressure gradient force is extremely unstable within the 250 km range of the right (240–300°) and 200 km range of the left (60–120°) regions of the mean TC. The sensitivity of the centrifugal force to radial changes surpasses that of azimuthal changes, and significant variations are concentrated within a radial distance of 50 km. For the Coriolis force, noticeable anisotropic features are evident within the 150 km radius of the 210–330° sector. Additionally, a comparison of the observed radial pressure profile with empirical pressure models was conducted. We found that B parameter values between 0.7 and 1.0 are optimal for our observational cases. Selecting an appropriate environmental pressure can bring the empirical model closer to the observed data. This study establishes a realistic foundation for enhancing existing sea surface parametric wind models of TCs and developing novel approaches, thereby ultimately improving the numerical calculation accuracy for storm surges and other air–sea interactions.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"318 ","pages":"Article 107986"},"PeriodicalIF":4.5,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-17DOI: 10.1016/j.atmosres.2025.107997
Fei Yang , Yue Sun , Mingjia Liu , Shiji Song , Weicong Chen , Zhicai Li , Lei Wang
Atmospheric weighted mean temperature (Tm) is an important parameter in the Global Navigation Satellite System (GNSS) meteorology, essential for retrieving precipitable water vapor (PWV). The FengYun-4 satellite (FY-4) carries Geostationary Interferometric Infrared Sounder (GIIRS), which realizes the transition from two-dimensional to three-dimensional detection of the vertical structure of the atmosphere in geostationary orbit, providing a more convenient and accurate data source for the inversion of Tm. The study presents a novel approach for deriving the Tm based on the GIIRS products of FengYun-4A satellite (FY-4A) and FengYun-4B satellite (FY-4B). The Tm calculated from the radiosonde data is utilized as reference to assess the performance of FY-4A and FY-4B, which demonstrates that the GIIRS equipped on FY-4 can provide a new way to obtain the Tm. The numerical results show that the mean absolute error (MAE) and root mean square error (RMSE) are 1.65/ 2.06 K and 1.38/ 1.73 K for FY-4A and FY-4B, respectively. The different performance of FY-4A and FY-4B on Tm are also observed from the analysis of the geographical distribution, seasons and epochs. Specifically, the RMSE distribution of FY-4A at different stations ranges from 1.08 to 3.47 K, while the distribution of FY-4B is more concentrated between 1.37 and 2.70 K. The accuracy of FY-4 A deteriorates as increasing latitude, while the phenomenon is not obvious for FY-4B. Moreover, FY-4 A performs slightly better at UTC 0:00 than at UTC 12:00, while FY-4B has a slightly better performance in autumn than in other seasons.
大气加权平均温度（Tm）是全球导航卫星系统（GNSS）气象学中的一个重要参数，对于检索可降水水汽（PWV）至关重要。风云四号卫星（FY-4）搭载了静止轨道干涉红外探测器（GIIRS），实现了静止轨道大气垂直结构从二维探测到三维探测的转变，为Tm的反演提供了更便捷、更准确的数据源。该研究提出了一种基于风云四号 A 卫星（FY-4A）和风云四号 B 卫星（FY-4B）的 GIIRS 产品推导 Tm 的新方法。利用无线电探测仪数据计算出的Tm作为参考，评估了风云四号A卫星和风云四号B卫星的性能，证明了风云四号卫星上配备的GIIRS可以提供一种获取Tm的新方法。数值结果表明，FY-4A 和 FY-4B 的平均绝对误差（MAE）和均方根误差（RMSE）分别为 1.65/ 2.06 K 和 1.38/ 1.73 K。FY-4A 和 FY-4B 在 Tm 上的不同性能还可以从地理分布、季节和历时分析中观察到。具体来说，FY-4A 在不同站点的均方根误差分布范围在 1.08 至 3.47 K 之间，而 FY-4B 则更集中在 1.37 至 2.70 K 之间。此外，FY-4 A 在协调世界时 0:00 的表现略好于协调世界时 12:00，而 FY-4B 在秋季的表现略好于其他季节。
{"title":"A new way to obtain the weighted mean temperature (Tm): Using the Geostationary Interferometric Infrared Sounder (GIIRS) equipped on FengYun Satellite","authors":"Fei Yang , Yue Sun , Mingjia Liu , Shiji Song , Weicong Chen , Zhicai Li , Lei Wang","doi":"10.1016/j.atmosres.2025.107997","DOIUrl":"10.1016/j.atmosres.2025.107997","url":null,"abstract":"<div><div>Atmospheric weighted mean temperature (Tm) is an important parameter in the Global Navigation Satellite System (GNSS) meteorology, essential for retrieving precipitable water vapor (PWV). The FengYun-4 satellite (FY-4) carries Geostationary Interferometric Infrared Sounder (GIIRS), which realizes the transition from two-dimensional to three-dimensional detection of the vertical structure of the atmosphere in geostationary orbit, providing a more convenient and accurate data source for the inversion of Tm. The study presents a novel approach for deriving the Tm based on the GIIRS products of FengYun-4A satellite (FY-4A) and FengYun-4B satellite (FY-4B). The Tm calculated from the radiosonde data is utilized as reference to assess the performance of FY-4A and FY-4B, which demonstrates that the GIIRS equipped on FY-4 can provide a new way to obtain the Tm. The numerical results show that the mean absolute error (MAE) and root mean square error (RMSE) are 1.65/ 2.06 K and 1.38/ 1.73 K for FY-4A and FY-4B, respectively. The different performance of FY-4A and FY-4B on Tm are also observed from the analysis of the geographical distribution, seasons and epochs. Specifically, the RMSE distribution of FY-4A at different stations ranges from 1.08 to 3.47 K, while the distribution of FY-4B is more concentrated between 1.37 and 2.70 K. The accuracy of FY-4 A deteriorates as increasing latitude, while the phenomenon is not obvious for FY-4B. Moreover, FY-4 A performs slightly better at UTC 0:00 than at UTC 12:00, while FY-4B has a slightly better performance in autumn than in other seasons.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"318 ","pages":"Article 107997"},"PeriodicalIF":4.5,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465408","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 West Sumatra region experienced devastating floods and landslides due to intense rainfall on March 7–8, 2024, with precipitation ranging from 200 to 394 mm/day exceeding the extreme rainfall threshold of 150 mm/day. We investigated the atmospheric dynamics to understand the mechanisms underlying this event. We used satellite data from Himawari-8 and Global Satellite Mapping of Precipitation (GSMaP) and ground-based observations to analyze cloud development and rainfall distribution. Wind velocity, Integrated Water Vapor Transport (IVT), Convective Available Potential Energy (CAPE), Convective Inhibition (CINH), K-Index, Vertically Integrated Moisture Flux Convergence (VIMFC), and Outgoing Longwave Radiation (OLR) from ERA5 reanalysis datasets are used to analyze convective instability and identify Equatorial waves. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model was employed to assess moisture transport. Our findings indicate that extreme rainfall was driven by the Mesoscale Convective System (MCS), as confirmed by cloud observations from Himawari-8. Further analysis revealed that moisture convergence, intensified by a Westerly Wind Burst (WWB) from the Indian Ocean, interacted with local topography and atmospheric circulations over West Sumatra. This interaction was associated with an active Madden-Julian Oscillation (MJO) in Phase 4, strengthening the westerly winds, transporting moisture and fueling convection. Before the event, MJO activity in Phase 3 over the Indian Ocean coincided with an atmospheric Kelvin wave, intensifying low-level convergence, enriching the Indian Ocean region with moisture, and transporting it to West Sumatra via the WWB. The interplay of the MJO, WWB, and Kelvin waves likely amplified the event. This study provides insights into the atmospheric processes behind this event and highlights their importance in developing early warning systems for future events.
{"title":"The role of Madden-Julian Oscillation, Westerly Wind Bursts, and Kelvin Waves in triggering extreme rainfall through Mesoscale Convective Systems: A case study of West Sumatra, March 7–8, 2024","authors":"Elfira Saufina , Trismidianto , Didi Satiadi , Wendi Harjupa , Risyanto , Anis Purwaningsih , Ibnu Fathrio , Alfan Sukmana Praja , Ina Juaeni , Adi Witono , Fahmi Rahmatia , Ridho Pratama , Muhaji Sahnita Putri , Putri Wulandari","doi":"10.1016/j.atmosres.2025.107993","DOIUrl":"10.1016/j.atmosres.2025.107993","url":null,"abstract":"<div><div>The West Sumatra region experienced devastating floods and landslides due to intense rainfall on March 7–8, 2024, with precipitation ranging from 200 to 394 mm/day exceeding the extreme rainfall threshold of 150 mm/day. We investigated the atmospheric dynamics to understand the mechanisms underlying this event. We used satellite data from Himawari-8 and Global Satellite Mapping of Precipitation (GSMaP) and ground-based observations to analyze cloud development and rainfall distribution. Wind velocity, Integrated Water Vapor Transport (IVT), Convective Available Potential Energy (CAPE), Convective Inhibition (CINH), K-Index, Vertically Integrated Moisture Flux Convergence (VIMFC), and Outgoing Longwave Radiation (OLR) from ERA5 reanalysis datasets are used to analyze convective instability and identify Equatorial waves. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model was employed to assess moisture transport. Our findings indicate that extreme rainfall was driven by the Mesoscale Convective System (MCS), as confirmed by cloud observations from Himawari-8. Further analysis revealed that moisture convergence, intensified by a Westerly Wind Burst (WWB) from the Indian Ocean, interacted with local topography and atmospheric circulations over West Sumatra. This interaction was associated with an active Madden-Julian Oscillation (MJO) in Phase 4, strengthening the westerly winds, transporting moisture and fueling convection. Before the event, MJO activity in Phase 3 over the Indian Ocean coincided with an atmospheric Kelvin wave, intensifying low-level convergence, enriching the Indian Ocean region with moisture, and transporting it to West Sumatra via the WWB. The interplay of the MJO, WWB, and Kelvin waves likely amplified the event. This study provides insights into the atmospheric processes behind this event and highlights their importance in developing early warning systems for future events.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"318 ","pages":"Article 107993"},"PeriodicalIF":4.5,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444594","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 : 2025-02-15DOI: 10.1016/j.atmosres.2025.107992
Chao Peng , Mi Tian , Guangming Shi , Shumin Zhang , Xin Long , Hanxiong Che , Jie Zhong , Xiangyu You , Zhier Bao , Fumo Yang , Xin Qi , Chongzhi Zhai , Yang Chen
The optical properties of brown carbon (BrC) and their correlation with chemical characteristics remained inadequately understood in different regions worldwide. This study investigated the correlations and estimated the subsequent radiative effects using real-time measurements during wintertime in the Sichuan Basin, China. The average light absorption of BrC (AbsBrC) at 370 nm constituted 35.5 ± 8.2 % of total absorption, significantly higher than those at 470 nm (20.9 ± 4.3 %), 590 nm (14.0 ± 2.5 %), and 660 nm (7.7 ± 2.1 %) (p < 0.001). The contributions of various organic aerosol (OA) sources to AbsBrC varied by wavelength, with biomass-burning OA (BBOA) and semi-volatile oxygenated OA (SVOOA) exhibiting the higher Abs (14.4 Mm−1 and 13.5 Mm−1), absorption Ångström exponents (AAE) (4.81 and 4.35), and contributions to AbsBrC (24.4 % and 22.8 %). Additionally, secondary BrC likely formed from BBOA through aqueous-phase reactions during winter. The transport of BBOA and SVOOA from northern regions (i.e., Guang'an in Sichuan and Hechuan in Chongqing) significantly contributed to elevated Abs370,BrC levels. The mean simple forcing efficiency for BrC (SFEBrC) was 60.5 W g−1, accounting for 14 % of SFEBC in the 370–880 nm range during winter. Overall, this study enhanced the understanding of AbsBrC and its evolution with sources, providing a more accurate assessment of its radiative effects, and emphasized the importance of biomass burning emissions.
{"title":"Sources and light absorption of brown carbon in urban areas of the Sichuan Basin, China: Contribution from biomass burning and secondary formation","authors":"Chao Peng , Mi Tian , Guangming Shi , Shumin Zhang , Xin Long , Hanxiong Che , Jie Zhong , Xiangyu You , Zhier Bao , Fumo Yang , Xin Qi , Chongzhi Zhai , Yang Chen","doi":"10.1016/j.atmosres.2025.107992","DOIUrl":"10.1016/j.atmosres.2025.107992","url":null,"abstract":"<div><div>The optical properties of brown carbon (BrC) and their correlation with chemical characteristics remained inadequately understood in different regions worldwide. This study investigated the correlations and estimated the subsequent radiative effects using real-time measurements during wintertime in the Sichuan Basin, China. The average light absorption of BrC (Abs<sub>BrC</sub>) at 370 nm constituted 35.5 ± 8.2 % of total absorption, significantly higher than those at 470 nm (20.9 ± 4.3 %), 590 nm (14.0 ± 2.5 %), and 660 nm (7.7 ± 2.1 %) (<em>p</em> < 0.001). The contributions of various organic aerosol (OA) sources to Abs<sub>BrC</sub> varied by wavelength, with biomass-burning OA (BBOA) and semi-volatile oxygenated OA (SVOOA) exhibiting the higher Abs (14.4 Mm<sup>−1</sup> and 13.5 Mm<sup>−1</sup>), absorption Ångström exponents (AAE) (4.81 and 4.35), and contributions to Abs<sub>BrC</sub> (24.4 % and 22.8 %). Additionally, secondary BrC likely formed from BBOA through aqueous-phase reactions during winter. The transport of BBOA and SVOOA from northern regions (i.e., Guang'an in Sichuan and Hechuan in Chongqing) significantly contributed to elevated Abs<sub>370,BrC</sub> levels. The mean simple forcing efficiency for BrC (SFE<sub>BrC</sub>) was 60.5 W g<sup>−1</sup>, accounting for 14 % of SFE<sub>BC</sub> in the 370–880 nm range during winter. Overall, this study enhanced the understanding of Abs<sub>BrC</sub> and its evolution with sources, providing a more accurate assessment of its radiative effects, and emphasized the importance of biomass burning emissions.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"318 ","pages":"Article 107992"},"PeriodicalIF":4.5,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437585","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 : 2025-02-14DOI: 10.1016/j.atmosres.2025.107987
Konstantinos Dimitriou
The main objective of this research, was to incorporate Mixed Layer Depth (MLD) estimations across backward air mass trajectories to the broadly used Trajectory Sector Analysis (TSA) and Concentration Weighted Trajectory (CWT) methods, in order to attain a three-dimensional (3D) identification of aerosol transport pathways and to reveal the role of the Mixed Layer (ML) on the transferring of particulates. The developed 3D-TSA and 3D-CWT tools, were combined with daily concentrations of PM10-bound , , , , and measured at three rural sampling sites in Spain during the years 2019–2020. Vertically extended Saharan dust intrusions from North Africa were associated with air masses travelling both inside and outside the ML and were related to increases of PM10-bound and at all stations, attributed to the reactions of mineral dust with gaseous precursors of such as SO2. The advection of sea salt particles, marked by high levels of and , was associated with marine air masses from the Mediterranean and Atlantic Ocean, moving mainly within the ML. Enhanced levels of PM10 constituents emitted by anthropogenic sources, such as (traffic and industrial emissions) and (biomass burning), were clearly related to air masses originating from Iberian Peninsula, Central Europe and North African coastline, whilst in most cases the strongest contributions were transferred by air masses moving above the ML. Therefore, the implemented 3D version of TSA and CWT methods, revealed new information regarding the altitudinal characteristics of air masses affecting PM10 levels in Spain.
{"title":"The influence of mixed layer depth along the course of incoming air masses to the transport of PM10 components at three rural sampling sites in Spain","authors":"Konstantinos Dimitriou","doi":"10.1016/j.atmosres.2025.107987","DOIUrl":"10.1016/j.atmosres.2025.107987","url":null,"abstract":"<div><div>The main objective of this research, was to incorporate Mixed Layer Depth (MLD) estimations across backward air mass trajectories to the broadly used Trajectory Sector Analysis (TSA) and Concentration Weighted Trajectory (CWT) methods, in order to attain a three-dimensional (3D) identification of aerosol transport pathways and to reveal the role of the Mixed Layer (ML) on the transferring of particulates. The developed 3D-TSA and 3D-CWT tools, were combined with daily concentrations of PM<sub>10</sub>-bound <span><math><msubsup><mi>SO</mi><mn>4</mn><mrow><mn>2</mn><mo>−</mo></mrow></msubsup></math></span>, <span><math><msubsup><mi>NO</mi><mn>3</mn><mo>−</mo></msubsup></math></span>, <span><math><msup><mi>Na</mi><mo>+</mo></msup></math></span>, <span><math><msup><mi>Mg</mi><mrow><mn>2</mn><mo>+</mo></mrow></msup></math></span>, <span><math><msup><mi>Ca</mi><mrow><mn>2</mn><mo>+</mo></mrow></msup></math></span> and <span><math><msup><mi>K</mi><mo>+</mo></msup></math></span> measured at three rural sampling sites in Spain during the years 2019–2020. Vertically extended Saharan dust intrusions from North Africa were associated with air masses travelling both inside and outside the ML and were related to increases of PM<sub>10</sub>-bound <span><math><msubsup><mi>SO</mi><mn>4</mn><mrow><mn>2</mn><mo>−</mo></mrow></msubsup></math></span> and <span><math><msup><mi>Ca</mi><mrow><mn>2</mn><mo>+</mo></mrow></msup></math></span> at all stations, attributed to the reactions of mineral dust with gaseous precursors of <span><math><msubsup><mi>SO</mi><mn>4</mn><mrow><mn>2</mn><mo>−</mo></mrow></msubsup></math></span> such as SO<sub>2</sub>. The advection of sea salt particles, marked by high levels of <span><math><msup><mi>Na</mi><mo>+</mo></msup></math></span> and <span><math><msup><mi>Mg</mi><mrow><mn>2</mn><mo>+</mo></mrow></msup></math></span>, was associated with marine air masses from the Mediterranean and Atlantic Ocean, moving mainly within the ML. Enhanced levels of PM<sub>10</sub> constituents emitted by anthropogenic sources, such as <span><math><msubsup><mi>NO</mi><mn>3</mn><mo>−</mo></msubsup></math></span> (traffic and industrial emissions) and <span><math><msup><mi>K</mi><mo>+</mo></msup></math></span> (biomass burning), were clearly related to air masses originating from Iberian Peninsula, Central Europe and North African coastline, whilst in most cases the strongest contributions were transferred by air masses moving above the ML. Therefore, the implemented 3D version of TSA and CWT methods, revealed new information regarding the altitudinal characteristics of air masses affecting PM<sub>10</sub> levels in Spain.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"317 ","pages":"Article 107987"},"PeriodicalIF":4.5,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143428010","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 : 2025-02-14DOI: 10.1016/j.atmosres.2025.107991
Peilan Huang , Qilin Wan , Lifang Li , Sheng Hu
Numerical models frequently cannot accurately predict warm-sector heavy rainfall (WSHR) in South China, which presents a challenge in forecasting severe weather events in the region. Considering the substantial impact of complex orography on the forecasting of WSHR in South China, to improve the accuracy of numerical models in predicting WSHR, this study utilized the non-hydrostatic mesoscale numerical model Weather Research Forecast (WRF) to simulate a WSHR event in the Pearl River Delta from 12:00 UTC on May 9, 2022, to 12:00 UTC on May 11, 2022. The modulation effect of Turbulent Orographic Form Drag (TOFD) on the prediction accuracy of the WSHR was investigated through sensitivity tests. The simulations suggest that TOFD improved the forecasting accuracy for WSHR in South China. TOFD significantly impacted the intensity and location of WSHR in the Pearl River Delta region. After incorporating TOFD, the forecast accuracy of WSHR improved in some regions (such as Guangzhou). Specifically, in the Pearl River Delta region, the TS score for 6-h heavy precipitation (>100 mm) increases by 91.12 %. The precipitation center shifts eastward, and the area affected by WSHR expands. Furthermore, the incorporation of TOFD in the simulations resulted in a delay of the WSHR onset time by 1–2 h and an extension of its duration by 1 h. Both these improvements brought the model results closer to actual observations. Additionally, with the inclusion of TOFD, the weakening of southerly winds has led to enhanced wind field convergence and stronger moisture convergence, resulting in increased moisture. In warm and moist atmospheric environments, there was an extended period of energy accumulation, resulting in a thicker mixed layer, increased negative buoyancy, and intensified upward airflow. As the system continued to move eastward, incorporating TOFD resulted in a further eastward positioning of the WSHR. Additionally, the intensity of the WSHR was stronger and the duration of intense precipitation was longer. The study highlights the critical role of TOFD in the realistic representation of WSHR by numerical models for South China.
{"title":"Numerical simulation and analysis of the modulation effect of sub-grid turbulent orographic form drag on warm-sector heavy rainfall in South China","authors":"Peilan Huang , Qilin Wan , Lifang Li , Sheng Hu","doi":"10.1016/j.atmosres.2025.107991","DOIUrl":"10.1016/j.atmosres.2025.107991","url":null,"abstract":"<div><div>Numerical models frequently cannot accurately predict warm-sector heavy rainfall (WSHR) in South China, which presents a challenge in forecasting severe weather events in the region. Considering the substantial impact of complex orography on the forecasting of WSHR in South China, to improve the accuracy of numerical models in predicting WSHR, this study utilized the non-hydrostatic mesoscale numerical model Weather Research Forecast (WRF) to simulate a WSHR event in the Pearl River Delta from 12:00 UTC on May 9, 2022, to 12:00 UTC on May 11, 2022. The modulation effect of Turbulent Orographic Form Drag (TOFD) on the prediction accuracy of the WSHR was investigated through sensitivity tests. The simulations suggest that TOFD improved the forecasting accuracy for WSHR in South China. TOFD significantly impacted the intensity and location of WSHR in the Pearl River Delta region. After incorporating TOFD, the forecast accuracy of WSHR improved in some regions (such as Guangzhou). Specifically, in the Pearl River Delta region, the TS score for 6-h heavy precipitation (>100 mm) increases by 91.12 %. The precipitation center shifts eastward, and the area affected by WSHR expands. Furthermore, the incorporation of TOFD in the simulations resulted in a delay of the WSHR onset time by 1–2 h and an extension of its duration by 1 h. Both these improvements brought the model results closer to actual observations. Additionally, with the inclusion of TOFD, the weakening of southerly winds has led to enhanced wind field convergence and stronger moisture convergence, resulting in increased moisture. In warm and moist atmospheric environments, there was an extended period of energy accumulation, resulting in a thicker mixed layer, increased negative buoyancy, and intensified upward airflow. As the system continued to move eastward, incorporating TOFD resulted in a further eastward positioning of the WSHR. Additionally, the intensity of the WSHR was stronger and the duration of intense precipitation was longer. The study highlights the critical role of TOFD in the realistic representation of WSHR by numerical models for South China.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"318 ","pages":"Article 107991"},"PeriodicalIF":4.5,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437604","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 : 2025-02-14DOI: 10.1016/j.atmosres.2025.107990
Ji-Young Han
This study aims to evaluate and improve the performance of the scale-aware cumulus parameterization scheme (CPS) in the Korean Integrated Model (KIM), referred to as KSAS. The performance of the KSAS for simulating precipitation over Korea is first evaluated in comparison with other scale-aware CPSs available in the Weather Research and Forecasting (WRF) model by conducting a series of experiments at multiple horizontal resolutions, including the gray zone. The results show that the KSAS significantly improves precipitation forecast skill compared to its original version. However, its performance is lower than that of the other scale-aware CPSs at 27-km and 9-km spatial resolutions due to the substantial contribution of cumulus parameterization. To address issues in the scale-aware parameterization of KSAS, the method for defining the convective updraft fraction is revised to adopt a more physically based approach. The WRF simulation results demonstrate improved precipitation forecast skill with the revised scale-aware parameterization at the gray-zone resolution, where the contribution of cumulus parameterization is significantly reduced. Further evaluation of the revised scheme in KIM also reveals enhanced medium-range forecast skill for both large-scale fields and precipitation at horizontal resolutions of NE360NP3 (∼12 km) and NE576NP3 (∼8 km). The warm bias in the mid-latitudes of the Northern Hemisphere is alleviated by reduced convective heating. Notably, the revised scheme exhibits a pronounced improvement in the skill for forecasting precipitation over the Korean Peninsula, better capturing the pattern and intensity of the precipitation core for heavy rainfall events, as confirmed by higher skill scores.
{"title":"Impact of different scale-aware cumulus parameterizations on precipitation forecasts over Korea","authors":"Ji-Young Han","doi":"10.1016/j.atmosres.2025.107990","DOIUrl":"10.1016/j.atmosres.2025.107990","url":null,"abstract":"<div><div>This study aims to evaluate and improve the performance of the scale-aware cumulus parameterization scheme (CPS) in the Korean Integrated Model (KIM), referred to as KSAS. The performance of the KSAS for simulating precipitation over Korea is first evaluated in comparison with other scale-aware CPSs available in the Weather Research and Forecasting (WRF) model by conducting a series of experiments at multiple horizontal resolutions, including the gray zone. The results show that the KSAS significantly improves precipitation forecast skill compared to its original version. However, its performance is lower than that of the other scale-aware CPSs at 27-km and 9-km spatial resolutions due to the substantial contribution of cumulus parameterization. To address issues in the scale-aware parameterization of KSAS, the method for defining the convective updraft fraction is revised to adopt a more physically based approach. The WRF simulation results demonstrate improved precipitation forecast skill with the revised scale-aware parameterization at the gray-zone resolution, where the contribution of cumulus parameterization is significantly reduced. Further evaluation of the revised scheme in KIM also reveals enhanced medium-range forecast skill for both large-scale fields and precipitation at horizontal resolutions of NE360NP3 (∼12 km) and NE576NP3 (∼8 km). The warm bias in the mid-latitudes of the Northern Hemisphere is alleviated by reduced convective heating. Notably, the revised scheme exhibits a pronounced improvement in the skill for forecasting precipitation over the Korean Peninsula, better capturing the pattern and intensity of the precipitation core for heavy rainfall events, as confirmed by higher skill scores.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"317 ","pages":"Article 107990"},"PeriodicalIF":4.5,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143428011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-13DOI: 10.1016/j.atmosres.2025.107981
Nasrin Salehnia , Chang-Hyun Park , Hotaek Park , Nikolai Fedorov , Jinho Ahn , Aleksander Fedorov , Seok-Woo Son
Over the past few decades, global warming has significantly impacted permafrost regions, reflecting the amplification in Arctic temperature changes. To better understand climate variability and the changes in permafrost regions, in this study, we examined the changes in the surface air temperature (SAT) in the Republic of Sakha (Yakutia, Russia) from 1971 to 2022. The data from 18 meteorological stations were considered to assess the SAT trends, percentage change (PC), and dominant periodic components across the region. Additionally, the trends of the snow depth (SD) and energy budget components (EBCs), including the net radiation (NR) and latent and sensible heat (LH and SH, respectively), were investigated to elucidate the possible reasons for the SAT trends. The results confirmed a significant increase in the SAT at all stations at both the monthly and seasonal timescales. The monthly SAT trends ranged from 0.002 °C/month to 0.007 °C/month, with considerable variations in the autumn and spring seasons. The dominant periodicity components that affected the SAT monthly trends were the 16- and 32-month across all the stations. For individual seasons, the 4- and 8-year periodic components were identified as the most dominant periodic components to affect the SAT, EBC, and SD trends. Our study can serve as a foundation for future investigations on the changes in dominant periodic components and energy budgets in subarctic regions due to global warming, thereby supporting the ongoing efforts toward climate change mitigation.
{"title":"Positive surface air temperature trends in a subarctic region: Analyzing the changes in dominant periodic components and energy budget","authors":"Nasrin Salehnia , Chang-Hyun Park , Hotaek Park , Nikolai Fedorov , Jinho Ahn , Aleksander Fedorov , Seok-Woo Son","doi":"10.1016/j.atmosres.2025.107981","DOIUrl":"10.1016/j.atmosres.2025.107981","url":null,"abstract":"<div><div>Over the past few decades, global warming has significantly impacted permafrost regions, reflecting the amplification in Arctic temperature changes. To better understand climate variability and the changes in permafrost regions, in this study, we examined the changes in the surface air temperature (SAT) in the Republic of Sakha (Yakutia, Russia) from 1971 to 2022. The data from 18 meteorological stations were considered to assess the SAT trends, percentage change (PC), and dominant periodic components across the region. Additionally, the trends of the snow depth (SD) and energy budget components (EBCs), including the net radiation (NR) and latent and sensible heat (LH and SH, respectively), were investigated to elucidate the possible reasons for the SAT trends. The results confirmed a significant increase in the SAT at all stations at both the monthly and seasonal timescales. The monthly SAT trends ranged from 0.002 °C/month to 0.007 °C/month, with considerable variations in the autumn and spring seasons. The dominant periodicity components that affected the SAT monthly trends were the 16- and 32-month across all the stations. For individual seasons, the 4- and 8-year periodic components were identified as the most dominant periodic components to affect the SAT, EBC, and SD trends. Our study can serve as a foundation for future investigations on the changes in dominant periodic components and energy budgets in subarctic regions due to global warming, thereby supporting the ongoing efforts toward climate change mitigation.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"318 ","pages":"Article 107981"},"PeriodicalIF":4.5,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444593","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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