Since 2013, heavy pollution episodes have occurred frequently over the North China Plain after unprecedented efforts to reduce primary pollutants. In this study, a pollution process in Tianjin, a typical city in North China, was selected to investigate the impact of 3-D meteorological patterns on PM2.5 and meteorological element profiles obtained by tethered balloons and meteorological towers. The pollution episode lasted 4 days with hourly PM2.5 concentrations exceeding 150 μg·m−3 for 81 h and a peak concentration of 377 μg·m−3. In the early stages of the first pollution period, wind speed with height showed an almost opposite trend to PM2.5 concentrations. In the vertical direction, weak winds were frequently accompanied by PM2.5 peaks, whereas strong winds were favourable for the diffusion of pollutants. In the later stage, a stable boundary layer with a height of approximately 600–700 m, thermal inversion layer capping the boundary layer, uniformly high-humidity atmosphere (>80 %), and relatively uniform distribution of wind speed across heights contributed to the high PM2.5, which remained within the boundary layer, and the continuous growth of surface PM2.5 concentrations. In the secondary pollution period, the successive regional transport of particles from Beijing and Baoding was the main reason for the two surface PM2.5 peaks in Tianjin. Different regional sources elevate PM2.5 levels, further extending the duration of haze pollution. The results reveal that 3-D meteorological conditions are the key reason for heavy pollution occurrence in the context of pollution reduction.
{"title":"Investigate the important role of 3-D meteorological patterns in haze formation in the context of pollution reduction","authors":"Miaomiao Lu, Suqin Han, Xiao Tang, Xueshun Chen, Kexin Liu, Jing Ding, Tianyi Hao, Zifa Wang","doi":"10.1016/j.atmosres.2024.107843","DOIUrl":"https://doi.org/10.1016/j.atmosres.2024.107843","url":null,"abstract":"Since 2013, heavy pollution episodes have occurred frequently over the North China Plain after unprecedented efforts to reduce primary pollutants. In this study, a pollution process in Tianjin, a typical city in North China, was selected to investigate the impact of 3-D meteorological patterns on PM<ce:inf loc=\"post\">2.5</ce:inf> and meteorological element profiles obtained by tethered balloons and meteorological towers. The pollution episode lasted 4 days with hourly PM<ce:inf loc=\"post\">2.5</ce:inf> concentrations exceeding 150 μg·m<ce:sup loc=\"post\">−3</ce:sup> for 81 h and a peak concentration of 377 μg·m<ce:sup loc=\"post\">−3</ce:sup>. In the early stages of the first pollution period, wind speed with height showed an almost opposite trend to PM<ce:inf loc=\"post\">2.5</ce:inf> concentrations. In the vertical direction, weak winds were frequently accompanied by PM<ce:inf loc=\"post\">2.5</ce:inf> peaks, whereas strong winds were favourable for the diffusion of pollutants. In the later stage, a stable boundary layer with a height of approximately 600–700 m, thermal inversion layer capping the boundary layer, uniformly high-humidity atmosphere (>80 %), and relatively uniform distribution of wind speed across heights contributed to the high PM<ce:inf loc=\"post\">2.5</ce:inf>, which remained within the boundary layer, and the continuous growth of surface PM<ce:inf loc=\"post\">2.5</ce:inf> concentrations. In the secondary pollution period, the successive regional transport of particles from Beijing and Baoding was the main reason for the two surface PM<ce:inf loc=\"post\">2.5</ce:inf> peaks in Tianjin. Different regional sources elevate PM<ce:inf loc=\"post\">2.5</ce:inf> levels, further extending the duration of haze pollution. The results reveal that 3-D meteorological conditions are the key reason for heavy pollution occurrence in the context of pollution reduction.","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"9 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142788925","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 : 2024-12-03DOI: 10.1016/j.atmosres.2024.107831
Bonu Koteswara Rao, K. Saikranthi
Two back-to-back heavy rainfall events (HREs) produced enormous rainfall over a pilgrim city, Tirupati, located in the southern peninsular India, during 10–12 November 2021 (149.2 mm) and 17–19 November 2021 (234.2 mm). Surface measurements at Yerpedu, Tirupati (13.74°, 79.60°E) showed a drop of 2–3 °C in temperature and 8 hPa in pressure during HREs, indicating that these HREs were associated with two landfalling tropical depressions from the Bay of Bengal. The sporadic HREs in the past three decades caused floods over Tirupati and devastated landslides in the sacred Tirumala hills especially during the second HRE. Fundamental understanding of diurnal cycle of surface radiation is critical to model the climate. The effect of HREs on the surface essential climate variables at diurnal scale indicate a reduction in peak solar and net radiations by 500 W m−2 (> 62.5 %). Similar to observations, ERA5 reanalysis also indicates a significant reduction in net surface solar and thermal radiations, which are nearly equal in terms of % but vary in magnitude. Net solar and thermal radiations show dominant diurnal cycles with a reduced (66.7 % and 74.4 % respectively) diurnal amplitudes from no-rain to HREs. Soil moisture drydown curves at 5- and 10-cm depths shows 3 h long e-folding decay time for HREs, indicating an enhanced soil moisture memory after HREs. The soil drying process takes longer time at 10 cm than at 5 cm depth. Soil temperatures are significantly low at 5 cm to 30 cm depths and less than the 50 cm depth with weak diurnal variation during the events. The reflectivity (Z)-rain rate (R) and shape (μ)-slope (Λ) relations show variations from HREs to normal rain events. Knowing the importance of land-atmospheric processes feedbacks in model predictions at diurnal scale, this study quantified the HREs impact on surface essential climate variables, especially the energy balance and soil variables.
{"title":"Observational evidence of impact of heavy rainfall events on surface energetics and soil variables over a tropical station Tirupati","authors":"Bonu Koteswara Rao, K. Saikranthi","doi":"10.1016/j.atmosres.2024.107831","DOIUrl":"https://doi.org/10.1016/j.atmosres.2024.107831","url":null,"abstract":"Two back-to-back heavy rainfall events (HREs) produced enormous rainfall over a pilgrim city, Tirupati, located in the southern peninsular India, during 10–12 November 2021 (149.2 mm) and 17–19 November 2021 (234.2 mm). Surface measurements at Yerpedu, Tirupati (13.74°, 79.60°E) showed a drop of 2–3 °C in temperature and 8 hPa in pressure during HREs, indicating that these HREs were associated with two landfalling tropical depressions from the Bay of Bengal. The sporadic HREs in the past three decades caused floods over Tirupati and devastated landslides in the sacred Tirumala hills especially during the second HRE. Fundamental understanding of diurnal cycle of surface radiation is critical to model the climate. The effect of HREs on the surface essential climate variables at diurnal scale indicate a reduction in peak solar and net radiations by 500 W m<ce:sup loc=\"post\">−2</ce:sup> (> 62.5 %). Similar to observations, ERA5 reanalysis also indicates a significant reduction in net surface solar and thermal radiations, which are nearly equal in terms of % but vary in magnitude. Net solar and thermal radiations show dominant diurnal cycles with a reduced (66.7 % and 74.4 % respectively) diurnal amplitudes from no-rain to HREs. Soil moisture drydown curves at 5- and 10-cm depths shows 3 h long e-folding decay time for HREs, indicating an enhanced soil moisture memory after HREs. The soil drying process takes longer time at 10 cm than at 5 cm depth. Soil temperatures are significantly low at 5 cm to 30 cm depths and less than the 50 cm depth with weak diurnal variation during the events. The reflectivity (<ce:italic>Z</ce:italic>)-rain rate (<ce:italic>R</ce:italic>) and shape (<ce:italic>μ</ce:italic>)-slope (<ce:italic>Λ</ce:italic>) relations show variations from HREs to normal rain events. Knowing the importance of land-atmospheric processes feedbacks in model predictions at diurnal scale, this study quantified the HREs impact on surface essential climate variables, especially the energy balance and soil variables.","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"27 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142788913","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 : 2024-12-03DOI: 10.1016/j.atmosres.2024.107845
Changyu Li, Wenmin Wei, Pak Wai Chan, Jianping Huang
Recently, the frequency of heatwaves has increased worldwide, with significant implications for public health, the environment, and socio-economic stability. In densely populated urban areas such as Hong Kong, heatwave events are of particular concern owing to their potential to exacerbate air pollution and modulate weather patterns, including extreme precipitation events. Despite extensive research on these phenomena, there exists a gap in understanding the interconnections of heatwaves, pollution, and extreme precipitation in subtropical urban climates. Utilising in-situ meteorological data from the Hong Kong Observatory (HKO), we investigated the characteristics of heatwaves and explored their impact on pollution and local rainfall. We observed a significant increase in the frequency, intensity, and duration of heatwaves in Hong Kong, particularly after 2010. Synoptic analysis indicates that these heatwaves are often associated with persistent high-pressure systems or tropical cyclones periphery downdrafts, as these patterns could induce subsidence and reduce cloud cover, which contributes to temperature increase. Additionally, heatwaves significantly elevated concentrations of ground-level ozone and particulate matter owing to increased photochemical reactions and stagnant air conditions. These pollution spikes coincide with heatwaves, aggravating public health risks. Furthermore, the increased frequency of heatwaves has altered the composition of local precipitation, with heatwave-following extreme precipitation events occurring more frequently, suggesting a thermal-driven amplification of the hydrological cycle. Our results highlight the urgent need for integrated urban planning and health policies that address the compounding effects of heatwaves, pollution, and subsequent extreme precipitation, underscoring the importance of adapting to and mitigating these linked phenomena amid a changing climate.
{"title":"Heatwaves in Hong Kong and their influence on pollution and extreme precipitation","authors":"Changyu Li, Wenmin Wei, Pak Wai Chan, Jianping Huang","doi":"10.1016/j.atmosres.2024.107845","DOIUrl":"https://doi.org/10.1016/j.atmosres.2024.107845","url":null,"abstract":"Recently, the frequency of heatwaves has increased worldwide, with significant implications for public health, the environment, and socio-economic stability. In densely populated urban areas such as Hong Kong, heatwave events are of particular concern owing to their potential to exacerbate air pollution and modulate weather patterns, including extreme precipitation events. Despite extensive research on these phenomena, there exists a gap in understanding the interconnections of heatwaves, pollution, and extreme precipitation in subtropical urban climates. Utilising in-situ meteorological data from the Hong Kong Observatory (HKO), we investigated the characteristics of heatwaves and explored their impact on pollution and local rainfall. We observed a significant increase in the frequency, intensity, and duration of heatwaves in Hong Kong, particularly after 2010. Synoptic analysis indicates that these heatwaves are often associated with persistent high-pressure systems or tropical cyclones periphery downdrafts, as these patterns could induce subsidence and reduce cloud cover, which contributes to temperature increase. Additionally, heatwaves significantly elevated concentrations of ground-level ozone and particulate matter owing to increased photochemical reactions and stagnant air conditions. These pollution spikes coincide with heatwaves, aggravating public health risks. Furthermore, the increased frequency of heatwaves has altered the composition of local precipitation, with heatwave-following extreme precipitation events occurring more frequently, suggesting a thermal-driven amplification of the hydrological cycle. Our results highlight the urgent need for integrated urban planning and health policies that address the compounding effects of heatwaves, pollution, and subsequent extreme precipitation, underscoring the importance of adapting to and mitigating these linked phenomena amid a changing climate.","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"47 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142788924","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 : 2024-12-03DOI: 10.1016/j.atmosres.2024.107848
Verónica M. Tur, Karim Sapag, Dimar Villarroel-Rocha, Diego Gaiero, María Laura López
Mineral aerosols are one of the most important ice nucleating particles (INPs) because their efficiency in nucleating ice, wide transport and largest mass contribution to particulate matter in the atmosphere. They are sourced from the arid regions of the world. In this context, this work evaluates the INP potential of fourteen topsoil samples collected from subtropical South American deserts, the major source of mineral aerosols in South America, in the immersion freezing mode. Samples were obtained from three distinct regions located in the South American Arid Diagonal and recognized as potential dust source areas: the Puna-Altiplano Plateau in the north, the central-west of Argentina, and Patagonia in the south. In general, results reveal that samples from the Puna-Altiplano and Patagonia regions, and the central-west of Argentina region exhibit the highest and lowest INP abilities, respectively. The active sites per unit surface area for a given temperature were calculated and compared with previously reported values. The results demonstrate that soil mineral particles from the region of study exhibit ice nucleating abilities comparable to the inorganic fraction of agricultural soils of central Argentina. No direct relationship was identified between INP ability and the major minerals observed in the samples. This study is the first to analyze the ice nucleation properties of soil samples collected along the South American Arid Diagonal and one of the few in South America. Since the analyzed topsoil particles were collected from potential dust source regions, this work contributes to understanding the role of aerosols in initiating atmospheric ice formation, providing valuable data for empirical parameterizations. This could contribute to the improvement in the performance of climate models, as the obtained results suggest that the underestimation of coarse and super-coarse aerosols at altitudes relevant for cloud formation may lead to underestimations in INP concentrations, particularly in regions near to the emission sources.
{"title":"Ice nucleating ability of mineral particles from subtropical South American deserts","authors":"Verónica M. Tur, Karim Sapag, Dimar Villarroel-Rocha, Diego Gaiero, María Laura López","doi":"10.1016/j.atmosres.2024.107848","DOIUrl":"https://doi.org/10.1016/j.atmosres.2024.107848","url":null,"abstract":"Mineral aerosols are one of the most important ice nucleating particles (INPs) because their efficiency in nucleating ice, wide transport and largest mass contribution to particulate matter in the atmosphere. They are sourced from the arid regions of the world. In this context, this work evaluates the INP potential of fourteen topsoil samples collected from subtropical South American deserts, the major source of mineral aerosols in South America, in the immersion freezing mode. Samples were obtained from three distinct regions located in the South American Arid Diagonal and recognized as potential dust source areas: the Puna-Altiplano Plateau in the north, the central-west of Argentina, and Patagonia in the south. In general, results reveal that samples from the Puna-Altiplano and Patagonia regions, and the central-west of Argentina region exhibit the highest and lowest INP abilities, respectively. The active sites per unit surface area for a given temperature were calculated and compared with previously reported values. The results demonstrate that soil mineral particles from the region of study exhibit ice nucleating abilities comparable to the inorganic fraction of agricultural soils of central Argentina. No direct relationship was identified between INP ability and the major minerals observed in the samples. This study is the first to analyze the ice nucleation properties of soil samples collected along the South American Arid Diagonal and one of the few in South America. Since the analyzed topsoil particles were collected from potential dust source regions, this work contributes to understanding the role of aerosols in initiating atmospheric ice formation, providing valuable data for empirical parameterizations. This could contribute to the improvement in the performance of climate models, as the obtained results suggest that the underestimation of coarse and super-coarse aerosols at altitudes relevant for cloud formation may lead to underestimations in INP concentrations, particularly in regions near to the emission sources.","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"18 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142788914","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}
Increasing heavy rainfall poses significant challenges in the Yangtze-Huaihe River Valley (YHRV). There is a need for more specific insights into the vertical microphysical structures and their influence on heavy rainfall to enhance the accuracy of numerical simulations and forecasts. Using data from the Dual-frequency Precipitation Radar (DPR) on the Global Precipitation Measurement (GPM) satellite from 2014 to 2023, this study investigated the vertical microphysical structures of different types of heavy summer rainfall (> 8 mm/h) and elucidated their impacts on the rain rate in the YHRV. Based on the radar reflectivity thresholds at different altitudes, heavy summer rainfall was classified into four types: deep convective, shallow convective, stratiform rainfall, and warm rainfall. In the YHRV region, shallow convective rainfall contributed the most to total heavy rainfall (39.1 %) and had the highest occurrence (44.7 %) of extreme rainfall (>50 mm/h). Stratiform rainfall occurred most frequently but decreased rapidly with increasing rain rates, while warm rainfall contributed little to heavy rainfall. For the vertical microphysical structure of heavy rainfall, deep convective rainfall exhibited rapid growth of large particles above the melting layer, resulting in the largest average mass-weighted diameter (Dm) near the surface (2.2 mm), but the smallest average droplet concentration (recorded as dBNw in the decibel scale), approximately 37. Below the melting layer, the Dm of small particles in the shallow convective rainfall increased rapidly, and the impact of coalescence was much greater than that of break-up. Except for warm rainfall, the average Dm for other types of heavy rainfall remained relatively high, exceeding 1.5 mm both within and below the melting layer. The average dBNw increased consistently as altitude decreased. As rainfall intensified to extreme rainfall, the average rain rate of shallow convective rainfall slightly surpassed that of deep convective rainfall. This was due to a decrease in average dBNw for deep convective rainfall, while the average dBNw of shallow convective rainfall continued to increase.
{"title":"Vertical microphysical structures of summer heavy rainfall in the Yangtze-Huaihe River Valley from GPM DPR data","authors":"Peng Hu, Leilei Kou, Wenjiao Wang, Haiyang Gao, Yanqing Xie, Liguo Zhang, Jian Shang","doi":"10.1016/j.atmosres.2024.107833","DOIUrl":"https://doi.org/10.1016/j.atmosres.2024.107833","url":null,"abstract":"Increasing heavy rainfall poses significant challenges in the Yangtze-Huaihe River Valley (YHRV). There is a need for more specific insights into the vertical microphysical structures and their influence on heavy rainfall to enhance the accuracy of numerical simulations and forecasts. Using data from the Dual-frequency Precipitation Radar (DPR) on the Global Precipitation Measurement (GPM) satellite from 2014 to 2023, this study investigated the vertical microphysical structures of different types of heavy summer rainfall (> 8 mm/h) and elucidated their impacts on the rain rate in the YHRV. Based on the radar reflectivity thresholds at different altitudes, heavy summer rainfall was classified into four types: deep convective, shallow convective, stratiform rainfall, and warm rainfall. In the YHRV region, shallow convective rainfall contributed the most to total heavy rainfall (39.1 %) and had the highest occurrence (44.7 %) of extreme rainfall (>50 mm/h). Stratiform rainfall occurred most frequently but decreased rapidly with increasing rain rates, while warm rainfall contributed little to heavy rainfall. For the vertical microphysical structure of heavy rainfall, deep convective rainfall exhibited rapid growth of large particles above the melting layer, resulting in the largest average mass-weighted diameter (<ce:italic>D</ce:italic><ce:inf loc=\"post\"><ce:italic>m</ce:italic></ce:inf>) near the surface (2.2 mm), but the smallest average droplet concentration (recorded as dBN<ce:inf loc=\"post\">w</ce:inf> in the decibel scale), approximately 37. Below the melting layer, the <ce:italic>D</ce:italic><ce:inf loc=\"post\"><ce:italic>m</ce:italic></ce:inf> of small particles in the shallow convective rainfall increased rapidly, and the impact of coalescence was much greater than that of break-up. Except for warm rainfall, the average <ce:italic>D</ce:italic><ce:inf loc=\"post\"><ce:italic>m</ce:italic></ce:inf> for other types of heavy rainfall remained relatively high, exceeding 1.5 mm both within and below the melting layer. The average dBN<ce:inf loc=\"post\">w</ce:inf> increased consistently as altitude decreased. As rainfall intensified to extreme rainfall, the average rain rate of shallow convective rainfall slightly surpassed that of deep convective rainfall. This was due to a decrease in average dBN<ce:inf loc=\"post\">w</ce:inf> for deep convective rainfall, while the average dBN<ce:inf loc=\"post\">w</ce:inf> of shallow convective rainfall continued to increase.","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"4 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142788929","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 : 2024-12-02DOI: 10.1016/j.atmosres.2024.107840
Hakan Aksu, Sait Genar Yaldiz
Defining regions with similar characteristics for extreme precipitation is crucial for understanding the impacts of climate change, planning and managing water resources, and designing hydraulic structures. However, studies on the regionalization of extreme precipitation for Türkiye are limited, and regional extreme precipitation characteristics are not well defined. In this study, motivated by the need to contribute to this field, homogenous regions for extreme precipitation across Türkiye were determined using the latest version (V07) of Integrated Multi-satellitE Retrievals for GPM (IMERG). We initially validated IMERG V07 estimates using data from 214 ground-based stations and compared the results with its predecessor V06. The results revealed that IMERG showed some notable improvements from V06 to V07 for all seasons, especially in winter. During this season, the correlation coefficient increased from 0.57 to 0.64, the mean absolute bias decreased from 78.22 % to 69.27 %, and the RMSE decreased from 11.10 mm/day to 9.70 mm/day. In V07, while the trend of decreasing accuracy with increasing elevation observed in V06 continues, it has been shown that some notable improvements were achieved in continuous and categorical metrics. We then applied widely used non-hierarchical (K-means) and hierarchical (Ward's method) clustering techniques. To perform this, we first applied Principal Component Analysis (PCA) to reduce the number of variables related to extreme precipitation (e.g. amount, frequency, standard deviation, and seasonality) and geographic characteristics to identify the most significant variables for analysis. The K-means method delineated Türkiye into eight extreme precipitation regions, while the Ward's method resulted in six distinct extreme precipitation regions. We evaluated the results based on the existing extreme precipitation climatology literature for Türkiye and by associating them to known precipitation dynamics, and as a result, we recommended eight precipitation regions determined by the K-means. The identified precipitation regions are expected to contribute to future studies analyzing the effects of climate change and to regional studies on natural disasters resulting from extreme precipitation.
{"title":"Performance comparison of GPM IMERG V07 with its predecessor V06 and its application in extreme precipitation clustering over Türkiye","authors":"Hakan Aksu, Sait Genar Yaldiz","doi":"10.1016/j.atmosres.2024.107840","DOIUrl":"https://doi.org/10.1016/j.atmosres.2024.107840","url":null,"abstract":"Defining regions with similar characteristics for extreme precipitation is crucial for understanding the impacts of climate change, planning and managing water resources, and designing hydraulic structures. However, studies on the regionalization of extreme precipitation for Türkiye are limited, and regional extreme precipitation characteristics are not well defined. In this study, motivated by the need to contribute to this field, homogenous regions for extreme precipitation across Türkiye were determined using the latest version (V07) of Integrated Multi-satellitE Retrievals for GPM (IMERG). We initially validated IMERG V07 estimates using data from 214 ground-based stations and compared the results with its predecessor V06. The results revealed that IMERG showed some notable improvements from V06 to V07 for all seasons, especially in winter. During this season, the correlation coefficient increased from 0.57 to 0.64, the mean absolute bias decreased from 78.22 % to 69.27 %, and the RMSE decreased from 11.10 mm/day to 9.70 mm/day. In V07, while the trend of decreasing accuracy with increasing elevation observed in V06 continues, it has been shown that some notable improvements were achieved in continuous and categorical metrics. We then applied widely used non-hierarchical (K-means) and hierarchical (Ward's method) clustering techniques. To perform this, we first applied Principal Component Analysis (PCA) to reduce the number of variables related to extreme precipitation (e.g. amount, frequency, standard deviation, and seasonality) and geographic characteristics to identify the most significant variables for analysis. The K-means method delineated Türkiye into eight extreme precipitation regions, while the Ward's method resulted in six distinct extreme precipitation regions. We evaluated the results based on the existing extreme precipitation climatology literature for Türkiye and by associating them to known precipitation dynamics, and as a result, we recommended eight precipitation regions determined by the K-means. The identified precipitation regions are expected to contribute to future studies analyzing the effects of climate change and to regional studies on natural disasters resulting from extreme precipitation.","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"3 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142788926","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 : 2024-12-02DOI: 10.1016/j.atmosres.2024.107844
Xi Cao, Renguang Wu, Pengfei Wang, Zhibiao Wang, Lei Zhou, Shangfeng Chen, Liang Wu, Suqin Zhang, Xianling Jiang, Zhencai Du, Yifeng Dai
The present study identifies a close linkage between spring (MAM) sea ice concentration (SIC) anomalies in the Greenland-Barents (GB) Seas and the tropical cyclone (TC) genesis frequency over the eastern North Pacific (ENP) in the subsequent summer and fall (JJASON) during 1979–2022. An increase in MAM GB SIC anomalies results in a decrease in subsequent JJASON ENP TC genesis frequency. The physical process for the influence of Arctic sea ice anomalies on TC formation is further examined. Detailed dynamical diagnosis reveals that a higher GB SIC during MAM results in an increase in upward shortwave radiation, leading to sea surface temperature (SST) cooling. This SST cooling triggers a teleconnection atmospheric wave train, traversing Eurasia, the northern Pacific and the northern America and reaching the northern Atlantic. The associated anomalous cyclone over mid-latitude northern Atlantic is accompanied by anomalous southwesterly winds over the subtropics, leading to SST warming in the subtropical northern Atlantic through weakening total wind speed and upward surface latent heat flux. SST warming in the subtropical northern Atlantic extends southward into the tropical Atlantic via wind-evaporation-SST feedback during the subsequent summer and autumn, which induces an anomalous zonal-vertical circulation with descending motion over the ENP. This descending motion reduces relative humidity and weakens local convection over the ENP, and thus is unfavorable for TC genesis there. This study suggests that the spring GB SIC could serve as a potential predictor of JJASON ENP TC genesis.
{"title":"Impact of Arctic Sea ice anomalies on tropical cyclogenesis over the eastern North Pacific: Role of northern Atlantic Sea surface temperature anomalies","authors":"Xi Cao, Renguang Wu, Pengfei Wang, Zhibiao Wang, Lei Zhou, Shangfeng Chen, Liang Wu, Suqin Zhang, Xianling Jiang, Zhencai Du, Yifeng Dai","doi":"10.1016/j.atmosres.2024.107844","DOIUrl":"https://doi.org/10.1016/j.atmosres.2024.107844","url":null,"abstract":"The present study identifies a close linkage between spring (MAM) sea ice concentration (SIC) anomalies in the Greenland-Barents (GB) Seas and the tropical cyclone (TC) genesis frequency over the eastern North Pacific (ENP) in the subsequent summer and fall (JJASON) during 1979–2022. An increase in MAM GB SIC anomalies results in a decrease in subsequent JJASON ENP TC genesis frequency. The physical process for the influence of Arctic sea ice anomalies on TC formation is further examined. Detailed dynamical diagnosis reveals that a higher GB SIC during MAM results in an increase in upward shortwave radiation, leading to sea surface temperature (SST) cooling. This SST cooling triggers a teleconnection atmospheric wave train, traversing Eurasia, the northern Pacific and the northern America and reaching the northern Atlantic. The associated anomalous cyclone over mid-latitude northern Atlantic is accompanied by anomalous southwesterly winds over the subtropics, leading to SST warming in the subtropical northern Atlantic through weakening total wind speed and upward surface latent heat flux. SST warming in the subtropical northern Atlantic extends southward into the tropical Atlantic via wind-evaporation-SST feedback during the subsequent summer and autumn, which induces an anomalous zonal-vertical circulation with descending motion over the ENP. This descending motion reduces relative humidity and weakens local convection over the ENP, and thus is unfavorable for TC genesis there. This study suggests that the spring GB SIC could serve as a potential predictor of JJASON ENP TC genesis.","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"8 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142816547","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}
Aerosols hygroscopicity and CCN activity in coastal area is influenced by continental-marine air interaction, probably exerting a profound climate effect. In this study, combining field measurement at a coastal site in Shenzhen with a back trajectory model, we have identified an externally-mixed sea salt mode in accumulated particles, where the hygroscopic parameter (κ) ranges from 0.97 to 1.14. The sea salt mode, however, was not observed for ultrafine particles in nucleation/Aitken modes. Nonetheless, the.
{"title":"Observed size-dependent effect of the marine air on aerosols hygroscopicity at a coastal site of Shenzhen, China","authors":"SongJian Zou, Lu Chen, Honghao Xu, Rou Zhang, Mengyu Liu, Guiquan Liu, Jianhuai Ye, Honglong Yang, Hao Wu, Yinshan Yang, Fang Zhang","doi":"10.1016/j.atmosres.2024.107830","DOIUrl":"https://doi.org/10.1016/j.atmosres.2024.107830","url":null,"abstract":"Aerosols hygroscopicity and CCN activity in coastal area is influenced by continental-marine air interaction, probably exerting a profound climate effect. In this study, combining field measurement at a coastal site in Shenzhen with a back trajectory model, we have identified an externally-mixed sea salt mode in accumulated particles, where the hygroscopic parameter (<ce:italic>κ</ce:italic>) ranges from 0.97 to 1.14. The sea salt mode, however, was not observed for ultrafine particles in nucleation/Aitken modes. Nonetheless, the.","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"82 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142788927","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 : 2024-11-30DOI: 10.1016/j.atmosres.2024.107827
E. Avolio, G. Castorina, R.C. Torcasio, S. Federico
A deep convective system affected the southern Mediterranean on 3–4 December 2022 causing heavy rains and wind gusts over three Italian regions (Sicily, Calabria, and Apulia) and a tornado in Calabria. We study the forecast sensitivity of this multi-hazard weather event to different physical parameterizations and configuration settings of the WRF (Weather Research and Forecasting) model, used at convection permitting horizontal resolution; in particular, we performed sensitivity tests on the role of the initial and boundary conditions, on the Sea Surface Temperature (SST), on the model horizontal resolution and on the cumulus parameterization. Moreover, a 6 h rapid update data assimilation analysis (3DVAR)/forecast cycle was investigated to further study the short-term forecast capabilities of the modeling system. Most of the WRF configurations are able to well simulate the characteristics of the weather system, even if there are differences among the configurations, especially at the local scale, which causes differences in forecast performances. We found that the quality of the forecast is sensitive to the initial and boundary conditions with the best members having a probability of detection around 30–40 % for rainfall intensities of 40–50 mm/6 h. Most of the forecasts decrease their performance for larger precipitation thresholds, with few exceptions. Specifically, we found that increasing the horizontal resolution was beneficial for the case study as the probability of detection remains larger than 0.2 for rainfall thresholds larger than 60 mm/6 h and up to 100 mm/6 h. In addition, the forecast with lightning and radar reflectivity data assimilation has a probability of detection larger than 0.4 for the same intense thresholds; in both cases false alarms are not increased. For the tornado simulation, no improvement was found adopting 3DVAR. A possible forecasting strategy for severe weather events is outlined.
{"title":"A multi hazard extreme weather event in Southern Italy: Assessment and sensitivity tests of the WRF model","authors":"E. Avolio, G. Castorina, R.C. Torcasio, S. Federico","doi":"10.1016/j.atmosres.2024.107827","DOIUrl":"https://doi.org/10.1016/j.atmosres.2024.107827","url":null,"abstract":"A deep convective system affected the southern Mediterranean on 3–4 December 2022 causing heavy rains and wind gusts over three Italian regions (Sicily, Calabria, and Apulia) and a tornado in Calabria. We study the forecast sensitivity of this multi-hazard weather event to different physical parameterizations and configuration settings of the WRF (Weather Research and Forecasting) model, used at convection permitting horizontal resolution; in particular, we performed sensitivity tests on the role of the initial and boundary conditions, on the Sea Surface Temperature (SST), on the model horizontal resolution and on the cumulus parameterization. Moreover, a 6 h rapid update data assimilation analysis (3DVAR)/forecast cycle was investigated to further study the short-term forecast capabilities of the modeling system. Most of the WRF configurations are able to well simulate the characteristics of the weather system, even if there are differences among the configurations, especially at the local scale, which causes differences in forecast performances. We found that the quality of the forecast is sensitive to the initial and boundary conditions with the best members having a probability of detection around 30–40 % for rainfall intensities of 40–50 mm/6 h. Most of the forecasts decrease their performance for larger precipitation thresholds, with few exceptions. Specifically, we found that increasing the horizontal resolution was beneficial for the case study as the probability of detection remains larger than 0.2 for rainfall thresholds larger than 60 mm/6 h and up to 100 mm/6 h. In addition, the forecast with lightning and radar reflectivity data assimilation has a probability of detection larger than 0.4 for the same intense thresholds; in both cases false alarms are not increased. For the tornado simulation, no improvement was found adopting 3DVAR. A possible forecasting strategy for severe weather events is outlined.","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"29 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142816549","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 : 2024-11-30DOI: 10.1016/j.atmosres.2024.107824
Serge Soula, Jean-François Georgis, David Salaün
{"title":"Corrigendum to “Quantifying the effect of wind turbines on lightning location and characteristics” [Atmospheric Research Volume 221, 30 January 2019]","authors":"Serge Soula, Jean-François Georgis, David Salaün","doi":"10.1016/j.atmosres.2024.107824","DOIUrl":"https://doi.org/10.1016/j.atmosres.2024.107824","url":null,"abstract":"","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"9 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142788928","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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