Pub Date : 2024-12-09DOI: 10.1016/j.atmosres.2024.107841
Marlen Kolbe, Richard Bintanja, Eveline C. van der Linden, Raúl R. Cordero
Recent extremes in Antarctic temperature, surface melt and sea ice loss have been robustly linked to the occurrence of atmospheric rivers (ARs). However, the precise mechanisms that generate variations in the surface impacts of ARs are poorly understood, especially in the Antarctic. Based on Arctic evidence that the vertical and horizontal advancement of ARs over sea ice strongly depends on meteorological conditions, the season, as well as the underlying surface before reaching sea ice, we investigate the vertical structure and impact of extreme ARs reaching sea ice and also the Antarctic ice sheet.
{"title":"Vertical structure and surface impact of atmospheric rivers reaching antarctic sea ice and land","authors":"Marlen Kolbe, Richard Bintanja, Eveline C. van der Linden, Raúl R. Cordero","doi":"10.1016/j.atmosres.2024.107841","DOIUrl":"https://doi.org/10.1016/j.atmosres.2024.107841","url":null,"abstract":"Recent extremes in Antarctic temperature, surface melt and sea ice loss have been robustly linked to the occurrence of atmospheric rivers (ARs). However, the precise mechanisms that generate variations in the surface impacts of ARs are poorly understood, especially in the Antarctic. Based on Arctic evidence that the vertical and horizontal advancement of ARs over sea ice strongly depends on meteorological conditions, the season, as well as the underlying surface before reaching sea ice, we investigate the vertical structure and impact of extreme ARs reaching sea ice and also the Antarctic ice sheet.","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"3 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142816539","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 : 2024-12-09DOI: 10.1016/j.atmosres.2024.107867
Zuohao Cao
Severe hail activities have significant impacts on our society because they damage property and are dangerous to people and animals. However, we have little knowledge on recent changes in geographic locations of severe hail activity center over Canada. Prior to exploring this, we have carried out Canada hail data consistency and reliability checks using solid trend analyses of three independent methods for time series of hail counts and days, and robust verifications of reported hail data by a recently developed approach of sample generation by replacement. Here, we discover for the first time a statistically significant east shift of Canada severe hail activity and total hail activity using discriminant analysis. The spatial shift is from the western portion of continental Canada during 2005–2013 to the eastern Canada with a maritime environment during 2014–2022. With increase of hail severity, the hail activities increase from the colder period 2005–2013 to the warmer period 2014–2022. Our composite analyses show that over the continental Canada, the hail activities are enriched through thermodynamically driven convective instability and precipitable water associated with the warming climate, as well as dynamically driven processes such as vertical wind shear and vertically integrated water vapor flux convergence. Over the maritime Canada with the colder condition, the hail activities are enhanced by dynamically driven moisture advection and convergence as well as vertical wind shear, thermodynamically driven process of precipitable water, and partially due to convective instability. This research promotes our understanding of climate change impact on hail activities, shedding lights on long-term hail projection, adaptation, and mitigation strategies.
{"title":"East shift of Canada severe hail activities in a changing climate","authors":"Zuohao Cao","doi":"10.1016/j.atmosres.2024.107867","DOIUrl":"https://doi.org/10.1016/j.atmosres.2024.107867","url":null,"abstract":"Severe hail activities have significant impacts on our society because they damage property and are dangerous to people and animals. However, we have little knowledge on recent changes in geographic locations of severe hail activity center over Canada. Prior to exploring this, we have carried out Canada hail data consistency and reliability checks using solid trend analyses of three independent methods for time series of hail counts and days, and robust verifications of reported hail data by a recently developed approach of sample generation by replacement. Here, we discover for the first time a statistically significant east shift of Canada severe hail activity and total hail activity using discriminant analysis. The spatial shift is from the western portion of continental Canada during 2005–2013 to the eastern Canada with a maritime environment during 2014–2022. With increase of hail severity, the hail activities increase from the colder period 2005–2013 to the warmer period 2014–2022. Our composite analyses show that over the continental Canada, the hail activities are enriched through thermodynamically driven convective instability and precipitable water associated with the warming climate, as well as dynamically driven processes such as vertical wind shear and vertically integrated water vapor flux convergence. Over the maritime Canada with the colder condition, the hail activities are enhanced by dynamically driven moisture advection and convergence as well as vertical wind shear, thermodynamically driven process of precipitable water, and partially due to convective instability. This research promotes our understanding of climate change impact on hail activities, shedding lights on long-term hail projection, adaptation, and mitigation strategies.","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"142 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142816548","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 : 2024-12-09DOI: 10.1016/j.atmosres.2024.107866
Li Ma, Zhigang Wei, Ruiqiang Ding, Xianru Li, Kaili Cheng
Variations in snow cover could have profound impacts on regional and large-scale circulations and climate anomalies. Previous studies have focused on their effects on mid- to low-latitude weather without considering the impacts on the Arctic climate. Here, we propose that the snow cover in Europe and Central Siberia is an important land factor for the early spring 2 m temperature (T2m) interannual variability in the Barents–Kara Sea (BKS). In years when there is less snow over Europe and Central Siberia, there are positive radiative forcing at the surface, which can lead to elevated surface air temperatures, contributing to upward surface sensible heat flux anomalies. Correspondingly, anomalous anticyclones appear in the mid-upper troposphere, accompanied by enhanced southwesterly winds over the northern side of Europe and southerly winds over the western side of Central Siberia, enhancing the transport of atmospheric heat and moisture to the BKS and their conservation. Such variations consequently increase the downwelling longwave radiation and T2m over the BKS. Moreover, the negative correlation between Eurasian SWE and BKS T2m can be identified by most CMIP6 models and by multi-model ensemble (MME) results. Additionally, the multidecadal fluctuations in the Eurasian SWE–Arctic T2m connection are strongly out of phase with the PDO index, which can be effectively captured in the CMIP6 MME results. Furthermore, among two different PDO- periods, the BKS T2m were influenced mainly by variation in SWE in Central Siberia during P1 (1962–1977) and, conversely, were impacted mainly by variation in SWE in Europe during P3 (1999–2012).
{"title":"Interannual responses of Arctic temperatures to Eurasian snow cover variations in early spring","authors":"Li Ma, Zhigang Wei, Ruiqiang Ding, Xianru Li, Kaili Cheng","doi":"10.1016/j.atmosres.2024.107866","DOIUrl":"https://doi.org/10.1016/j.atmosres.2024.107866","url":null,"abstract":"Variations in snow cover could have profound impacts on regional and large-scale circulations and climate anomalies. Previous studies have focused on their effects on mid- to low-latitude weather without considering the impacts on the Arctic climate. Here, we propose that the snow cover in Europe and Central Siberia is an important land factor for the early spring 2 m temperature (T2m) interannual variability in the Barents–Kara Sea (BKS). In years when there is less snow over Europe and Central Siberia, there are positive radiative forcing at the surface, which can lead to elevated surface air temperatures, contributing to upward surface sensible heat flux anomalies. Correspondingly, anomalous anticyclones appear in the mid-upper troposphere, accompanied by enhanced southwesterly winds over the northern side of Europe and southerly winds over the western side of Central Siberia, enhancing the transport of atmospheric heat and moisture to the BKS and their conservation. Such variations consequently increase the downwelling longwave radiation and T2m over the BKS. Moreover, the negative correlation between Eurasian SWE and BKS T2m can be identified by most CMIP6 models and by multi-model ensemble (MME) results. Additionally, the multidecadal fluctuations in the Eurasian SWE–Arctic T2m connection are strongly out of phase with the PDO index, which can be effectively captured in the CMIP6 MME results. Furthermore, among two different PDO- periods, the BKS T2m were influenced mainly by variation in SWE in Central Siberia during P1 (1962–1977) and, conversely, were impacted mainly by variation in SWE in Europe during P3 (1999–2012).","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"73 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142816542","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 : 2024-12-08DOI: 10.1016/j.atmosres.2024.107863
Jingxi Sun, Chunsong Lu, Yan Yin, Sinan Gao, Junjun Li, Yiwei Zhang
To enhance the understanding of the cloud and rain microphysical characteristics in Meiyu frontal systems, we performed a detailed analysis of stochastic collision processes in Meiyu frontal precipitation clouds, using observational data collected at the Bright Summit Meteorological Station on Huangshan (118°09′E, 30°08′N). By employing stochastic collection and breakup equations, this study investigates the primary microphysical processes influencing cloud and rain microphysical properties. Key findings are as follows: Compared to periods before and after the Meiyu season, the number concentration of small cloud droplets decreases, whereas the number concentration of large cloud droplets increases within the Meiyu season, because of relatively stronger collision-coalescence. Raindrop accretion of cloud droplets dominates the stochastic collision process, gradually reducing cloud droplet number concentration, especially, number concentration of small cloud droplets. Both cloud mean diameter and standard deviation increases with the decreasing cloud droplet number concentration, and the increase of standard deviation dominates. As a result, the correlation between cloud relative dispersion and number concentration is negative in general, but fluctuates for different number concentration ranges. This study enhances the understanding of cloud and rain microphysical processes and could be helpful to the development of microphysical parameterization schemes.
{"title":"Impact of stochastic collisions on cloud droplet number concentration and relative dispersion during Meiyu frontal system","authors":"Jingxi Sun, Chunsong Lu, Yan Yin, Sinan Gao, Junjun Li, Yiwei Zhang","doi":"10.1016/j.atmosres.2024.107863","DOIUrl":"https://doi.org/10.1016/j.atmosres.2024.107863","url":null,"abstract":"To enhance the understanding of the cloud and rain microphysical characteristics in Meiyu frontal systems, we performed a detailed analysis of stochastic collision processes in Meiyu frontal precipitation clouds, using observational data collected at the Bright Summit Meteorological Station on Huangshan (118°09′E, 30°08′N). By employing stochastic collection and breakup equations, this study investigates the primary microphysical processes influencing cloud and rain microphysical properties. Key findings are as follows: Compared to periods before and after the Meiyu season, the number concentration of small cloud droplets decreases, whereas the number concentration of large cloud droplets increases within the Meiyu season, because of relatively stronger collision-coalescence. Raindrop accretion of cloud droplets dominates the stochastic collision process, gradually reducing cloud droplet number concentration, especially, number concentration of small cloud droplets. Both cloud mean diameter and standard deviation increases with the decreasing cloud droplet number concentration, and the increase of standard deviation dominates. As a result, the correlation between cloud relative dispersion and number concentration is negative in general, but fluctuates for different number concentration ranges. This study enhances the understanding of cloud and rain microphysical processes and could be helpful to the development of microphysical parameterization schemes.","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"8 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142816540","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}
Drought forecasting is important for water resources management and effective response to drought, and the predictability of drought may change under a changing environment. Most of the studies have focused on developing drought forecasting techniques, but limited attention has been made to the theory of drought predictability, such as dynamics of meteorological drought predictability and possible driving mechanism. Here, we characterized the predictability of meteorological drought, based on the Kling-Gupta efficiency (KGE") coefficient of support vector machine regression model. Then we measured the spatial distribution, agglomeration, and dynamic changes of drought predictability, and quantitatively analyzed the main driving forces and relationships of the spatial and temporal dynamics. The Loess Plateau (LP), which is a drought-prone region with frail ecological environment in China, was chosen as a case study. Results indicated that: (1) drought predictability in the western region was higher than that in the eastern region of the LP, with the hot spots concentrated in the western sandy land and agricultural irrigation; (2) meteorological drought predictability in the LP showed a downward trend from 1962 to 2019 under the changing environment, which the autumn drought predictability declined significantly; (3) meteorological, terrestrial factors and air-sea coupling elements dominated the spatial-temporal pattern of meteorological drought predictability via strongly affecting the coefficient of variation of drought index series, and related causal paths were explored. This study sheds new light on drought predictability dynamics under a changing environment, and has significance for improving the ability of drought forecasting, warning, and mitigation.
{"title":"Meteorological drought predictability dynamics and possible driving mechanisms in a changing environment in the Loess Plateau, China","authors":"Yiting Wang, Shengzhi Huang, Vijay P. Singh, Haiyun Shi, Guoyong Leng, Qiang Huang, Jing Luo, Xudong Zheng, Jian Peng","doi":"10.1016/j.atmosres.2024.107842","DOIUrl":"https://doi.org/10.1016/j.atmosres.2024.107842","url":null,"abstract":"Drought forecasting is important for water resources management and effective response to drought, and the predictability of drought may change under a changing environment. Most of the studies have focused on developing drought forecasting techniques, but limited attention has been made to the theory of drought predictability, such as dynamics of meteorological drought predictability and possible driving mechanism. Here, we characterized the predictability of meteorological drought, based on the Kling-Gupta efficiency (KGE\") coefficient of support vector machine regression model. Then we measured the spatial distribution, agglomeration, and dynamic changes of drought predictability, and quantitatively analyzed the main driving forces and relationships of the spatial and temporal dynamics. The Loess Plateau (LP), which is a drought-prone region with frail ecological environment in China, was chosen as a case study. Results indicated that: (1) drought predictability in the western region was higher than that in the eastern region of the LP, with the hot spots concentrated in the western sandy land and agricultural irrigation; (2) meteorological drought predictability in the LP showed a downward trend from 1962 to 2019 under the changing environment, which the autumn drought predictability declined significantly; (3) meteorological, terrestrial factors and air-sea coupling elements dominated the spatial-temporal pattern of meteorological drought predictability via strongly affecting the coefficient of variation of drought index series, and related causal paths were explored. This study sheds new light on drought predictability dynamics under a changing environment, and has significance for improving the ability of drought forecasting, warning, and mitigation.","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"3 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142816541","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 : 2024-12-06DOI: 10.1016/j.atmosres.2024.107825
Prabhakar Namdev, Maithili Sharan, Saroj K. Mishra
Accurate representation of the stable atmospheric surface layer (ASL) in numerical models has been a challenging task due to the occurrence of different physical processes such as radiative transport, turbulent mixing, and the coupling of vegetation with the atmosphere and underlying soil, as well as aspects of land use heterogeneity, etc. The Monin-Obukhov similarity theory has been widely used to parameterize surface turbulent fluxes in numerical models, which utilize similarity functions to account for the effect of atmospheric stability. Over the years, researchers have proposed various forms of similarity functions, depending on different field experiment datasets around the globe. This study incorporates some of the well-established non-linear similarity functions under stable stratification in the revised MM5 surface layer scheme in the Weather Research and Forecasting (WRF) Model version 4.2.2 and hence develop a scheme that has various functional forms of similarity functions for computing surface turbulent fluxes under stable stratification. The proposed scheme has been evaluated in simulating near-surface atmospheric variables and surface turbulent fluxes over the domain centered around the location of the Ranchi dataset site (23.412oN, 85.440oE; India) and the CASES-99 experiment site (37.38oN, 96.44oW; Kansas, USA) during the months of January 2009 and October 1999, respectively. The modified scheme is also evaluated for the three contrasting nights representative of intermittently turbulent, fully turbulent, and radiative ASL based on the CASES-99 dataset. In general, all the newly installed similarity functions are found to be consistent in predicting surface turbulent fluxes as well as near-surface atmospheric variables with respect to the default surface layer scheme and the observed data derived from the flux towers over the two domains. However, this study reveals that all the similarity functions are found to be inconsistent during the fully turbulent night while they seem comparable for the first and last nights based on the CASES-99 dataset.
{"title":"Implementation of various non-linear similarity functions for stable atmospheric surface layer in the WRF modeling system: An evaluation for three contrasting nights in CASES-99 dataset","authors":"Prabhakar Namdev, Maithili Sharan, Saroj K. Mishra","doi":"10.1016/j.atmosres.2024.107825","DOIUrl":"https://doi.org/10.1016/j.atmosres.2024.107825","url":null,"abstract":"Accurate representation of the stable atmospheric surface layer (ASL) in numerical models has been a challenging task due to the occurrence of different physical processes such as radiative transport, turbulent mixing, and the coupling of vegetation with the atmosphere and underlying soil, as well as aspects of land use heterogeneity, etc. The Monin-Obukhov similarity theory has been widely used to parameterize surface turbulent fluxes in numerical models, which utilize similarity functions to account for the effect of atmospheric stability. Over the years, researchers have proposed various forms of similarity functions, depending on different field experiment datasets around the globe. This study incorporates some of the well-established non-linear similarity functions under stable stratification in the revised MM5 surface layer scheme in the Weather Research and Forecasting (WRF) Model version 4.2.2 and hence develop a scheme that has various functional forms of similarity functions for computing surface turbulent fluxes under stable stratification. The proposed scheme has been evaluated in simulating near-surface atmospheric variables and surface turbulent fluxes over the domain centered around the location of the Ranchi dataset site (23.412<ce:sup loc=\"post\">o</ce:sup>N, 85.440<ce:sup loc=\"post\">o</ce:sup>E; India) and the CASES-99 experiment site (37.38<ce:sup loc=\"post\">o</ce:sup>N, 96.44<ce:sup loc=\"post\">o</ce:sup>W; Kansas, USA) during the months of January 2009 and October 1999, respectively. The modified scheme is also evaluated for the three contrasting nights representative of intermittently turbulent, fully turbulent, and radiative ASL based on the CASES-99 dataset. In general, all the newly installed similarity functions are found to be consistent in predicting surface turbulent fluxes as well as near-surface atmospheric variables with respect to the default surface layer scheme and the observed data derived from the flux towers over the two domains. However, this study reveals that all the similarity functions are found to be inconsistent during the fully turbulent night while they seem comparable for the first and last nights based on the CASES-99 dataset.","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"249 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142816544","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}
Atmospheric electric filed (AEF) measured at the earthʼs surface varies in time and space in an irregular manner, which makes interpreting the results of such measurements a challenging task. Simultaneous measurements of the AEF using several sensors make it possible to study the spatiotemporal structure of AEF variations associated with local sources. In one dimension there is an optimal placement of sensors along a straight line with distances between them that are proportional to the divisions in the Golomb ruler such that, with a fixed number of sensors, there is a maximum possible number of different pairwise distances. An array of 7 electric field mills in a line and one more at a distance greater than the total length of the Golomb ruler was used to obtain simultaneous observational data set and estimate temporal and spatial autocorrelation functions of AEF variations in the range of distances 2.5–400 m and frequency range 10−3–1 Hz. In addition, to quantitatively describe and interpret the obtained dependences, the autocorrelation functions of the electric field created over a conducting plane by extended one-dimensional random Gaussian charge distribution with exponential autocorrelation function are analyzed. It is found that autocorrelation functions of observed and modeled electric field can be approximated by incomplete gamma functions with parameters depending on the height of charges and the correlation radius in charge distribution. The integral scales of AEF variations of local nature are examined depending on the same parameters, and the time integral scale is found to be inversely depends on the density of zeros of standardized time series of the AEF. The autocorrelation function of electric field created by charges, which are located at a distance from the earthʼs surface, much less than correlation radius in charge distribution, is the same as for the charges, and the rate of its decline decreases with increasing height of the system of charges.
{"title":"Estimation of autocorrelation functions of atmospheric electric field variations using a Golomb array of sensors","authors":"S.V. Anisimov, S.V. Galichenko, A.A. Prokhorchuk, E.V. Klimanova, A.S. Kozmina, K.V. Aphinogenov","doi":"10.1016/j.atmosres.2024.107847","DOIUrl":"https://doi.org/10.1016/j.atmosres.2024.107847","url":null,"abstract":"Atmospheric electric filed (AEF) measured at the earthʼs surface varies in time and space in an irregular manner, which makes interpreting the results of such measurements a challenging task. Simultaneous measurements of the AEF using several sensors make it possible to study the spatiotemporal structure of AEF variations associated with local sources. In one dimension there is an optimal placement of sensors along a straight line with distances between them that are proportional to the divisions in the Golomb ruler such that, with a fixed number of sensors, there is a maximum possible number of different pairwise distances. An array of 7 electric field mills in a line and one more at a distance greater than the total length of the Golomb ruler was used to obtain simultaneous observational data set and estimate temporal and spatial autocorrelation functions of AEF variations in the range of distances 2.5–400 m and frequency range 10<ce:sup loc=\"post\">−3</ce:sup>–1 Hz. In addition, to quantitatively describe and interpret the obtained dependences, the autocorrelation functions of the electric field created over a conducting plane by extended one-dimensional random Gaussian charge distribution with exponential autocorrelation function are analyzed. It is found that autocorrelation functions of observed and modeled electric field can be approximated by incomplete gamma functions with parameters depending on the height of charges and the correlation radius in charge distribution. The integral scales of AEF variations of local nature are examined depending on the same parameters, and the time integral scale is found to be inversely depends on the density of zeros of standardized time series of the AEF. The autocorrelation function of electric field created by charges, which are located at a distance from the earthʼs surface, much less than correlation radius in charge distribution, is the same as for the charges, and the rate of its decline decreases with increasing height of the system of charges.","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"41 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142816543","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}
Snowfall plays a crucial role in the mountainous cryosphere cycle and is significantly influenced by climate change. This study utilizes the global climate models (GCMs) from Coupled Model Intercomparison Project phase 6 (CMIP6) with multivariate bias correction (MBC) to explore potential future variations in snowfall and its elevation dependency across the Tibetan Plateau (TP). Findings indicate a consistent decline in annual snowfall across the majority of the TP by the end of the century, except for certain high-elevation regions in the northwest. The decreasing trend is projected to intensify with strengthen Shared Socioeconomic Pathway (SSP) scenarios and exhibits elevation dependency below 5000 m. Specifically, under the SSP5–8.5 scenario, snowfall over the TP is expected to decrease by 39.74 % in the far future (2071–2100), with the elevation zone below 2000 m experiencing the most intense decline of approximately 62 %. This trend is largely attributed to the significant warming, which reduces the snow fraction as more precipitation falls as rain rather than snow. This shift is evidenced by the identification of turning points in snow fraction in the mid-2040s to 2050s, coinciding with rapid temperature increases. Furthermore, substantial decreases in future (heavy) snowfall days contribute to the overall reduction in snowfall. However, complex interplay between increased precipitation and temperature effects results in a slight increase in snowfall over high elevation areas in the northern edge. Uncertainty analysis indicates model uncertainty as the dominant source in snowfall projections, accounting for over 50 % of total variance. The projected declines in snowfall and snow fraction, as well as shortened snowfall days could considerably impact the cryosphere, hydrological and ecological systems of the TP.
{"title":"Elevation dependency of snowfall changes under climate change over the Tibetan Plateau: Evidence from CMIP6 GCMs","authors":"Yiyan Gao, Minpei Zhou, Zhongbo Yu, Qin Ju, Lei Wen, Junliang Jin, Dawei Zhang","doi":"10.1016/j.atmosres.2024.107832","DOIUrl":"https://doi.org/10.1016/j.atmosres.2024.107832","url":null,"abstract":"Snowfall plays a crucial role in the mountainous cryosphere cycle and is significantly influenced by climate change. This study utilizes the global climate models (GCMs) from Coupled Model Intercomparison Project phase 6 (CMIP6) with multivariate bias correction (MBC) to explore potential future variations in snowfall and its elevation dependency across the Tibetan Plateau (TP). Findings indicate a consistent decline in annual snowfall across the majority of the TP by the end of the century, except for certain high-elevation regions in the northwest. The decreasing trend is projected to intensify with strengthen Shared Socioeconomic Pathway (SSP) scenarios and exhibits elevation dependency below 5000 m. Specifically, under the SSP5–8.5 scenario, snowfall over the TP is expected to decrease by 39.74 % in the far future (2071–2100), with the elevation zone below 2000 m experiencing the most intense decline of approximately 62 %. This trend is largely attributed to the significant warming, which reduces the snow fraction as more precipitation falls as rain rather than snow. This shift is evidenced by the identification of turning points in snow fraction in the mid-2040s to 2050s, coinciding with rapid temperature increases. Furthermore, substantial decreases in future (heavy) snowfall days contribute to the overall reduction in snowfall. However, complex interplay between increased precipitation and temperature effects results in a slight increase in snowfall over high elevation areas in the northern edge. Uncertainty analysis indicates model uncertainty as the dominant source in snowfall projections, accounting for over 50 % of total variance. The projected declines in snowfall and snow fraction, as well as shortened snowfall days could considerably impact the cryosphere, hydrological and ecological systems of the TP.","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"36 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142788912","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 mechanism of climate and vegetation change induced dust variations has been a phenomenal environmental concern in East Asia. However, the extent to which climate and vegetation cover separately affect the interannual variations of dust activity, is little known. Here in our study, the dust interannual variations and the contributions of climate and vegetation changes on dust variations were investigated and quantified through a regional climate model (RegCM4.9.5) and GeoDetector analysis. It is indicated that the dust aerosol optical depth, column burden and emission flux over East Asia all showed fluctuating downward trends followed by subsequent increases during 2000–2018. Climatic factors dominated the interannual variation of dust over East Asia, particularly the modulation of El Niño Southern Oscillation events. Vegetation improvement has occurred in most dust source regions across East Asia, playing a secondary yet positive role in dust variations, with an overall contribution rate of approximately 37 %. The spatial heterogeneity of dust variations in different regions was shaped by the effects of climate change and improved vegetation conditions.
{"title":"El Niño Southern oscillation events contribute significantly to the interannual variations of dust activity over East Asia","authors":"Ruibo Zhao, Xiaoming Feng, Chaowei Zhou, Yu Zhang, Xuejing Leng, Bojie Fu","doi":"10.1016/j.atmosres.2024.107846","DOIUrl":"https://doi.org/10.1016/j.atmosres.2024.107846","url":null,"abstract":"The mechanism of climate and vegetation change induced dust variations has been a phenomenal environmental concern in East Asia. However, the extent to which climate and vegetation cover separately affect the interannual variations of dust activity, is little known. Here in our study, the dust interannual variations and the contributions of climate and vegetation changes on dust variations were investigated and quantified through a regional climate model (RegCM4.9.5) and GeoDetector analysis. It is indicated that the dust aerosol optical depth, column burden and emission flux over East Asia all showed fluctuating downward trends followed by subsequent increases during 2000–2018. Climatic factors dominated the interannual variation of dust over East Asia, particularly the modulation of El Niño Southern Oscillation events. Vegetation improvement has occurred in most dust source regions across East Asia, playing a secondary yet positive role in dust variations, with an overall contribution rate of approximately 37 %. The spatial heterogeneity of dust variations in different regions was shaped by the effects of climate change and improved vegetation conditions.","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"29 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142816545","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 : 2024-12-04DOI: 10.1016/j.atmosres.2024.107829
Han Zhang, Ke Fan
In 2021, an exceptionally intense autumn rainfall event occurred in West China (WC), breaking historical precipitation records since 1961. A notable northward migration of rainfall center was observed during the season. This study utilized real-time forecast data from the ECMWF (European Centre for Medium-Range Weather Forecasts) and CMA (China Meteorological Administration) models under the S2S (Subseasonal-to-Seasonal Prediction) project to examine the subseasonal predictability of the extreme ARWC event and its associated systems, providing a theoretical basis for forecasting extreme autumn rainfall. The results showed that both models underestimated the observed anomalous precipitation, however, ECMWF was able to predict the spatial distribution and intensity of different phases of the event up to 8 days in advance, while the CMA model exhibited poor skill. ECMWF and CMA both successfully predicted the intraseasonal northward migration of the rainfall 8 days and 5 days in advance, respectively. Further analysis revealed that ECMWF and CMA can reproduce the mid–high-latitude wave patterns associated with the intraseasonal variations in the EAWJ at lead times of 1–10 days, contributing to better predictions of the intraseasonal northward migration of the rainfall. Their ability to predict the tropical convection differed, with ECMWF more accurately reproducing the anomalous dipole tropical convection activities over the Indo-Pacific Warm Pool and the central-eastern Pacific 1–22 days in advance, and the characteristic that the convection eventually weakens over the maritime continent. This led to better predictions of the intraseasonal variations of the WPSH, giving the ECMWF model a higher forecasting skill for both periods of the extreme ARWC in 2021 compared to the CMA model.
{"title":"Subseasonal predictability of the extreme autumn rainfall event in West China in 2021","authors":"Han Zhang, Ke Fan","doi":"10.1016/j.atmosres.2024.107829","DOIUrl":"https://doi.org/10.1016/j.atmosres.2024.107829","url":null,"abstract":"In 2021, an exceptionally intense autumn rainfall event occurred in West China (WC), breaking historical precipitation records since 1961. A notable northward migration of rainfall center was observed during the season. This study utilized real-time forecast data from the ECMWF (European Centre for Medium-Range Weather Forecasts) and CMA (China Meteorological Administration) models under the S2S (Subseasonal-to-Seasonal Prediction) project to examine the subseasonal predictability of the extreme ARWC event and its associated systems, providing a theoretical basis for forecasting extreme autumn rainfall. The results showed that both models underestimated the observed anomalous precipitation, however, ECMWF was able to predict the spatial distribution and intensity of different phases of the event up to 8 days in advance, while the CMA model exhibited poor skill. ECMWF and CMA both successfully predicted the intraseasonal northward migration of the rainfall 8 days and 5 days in advance, respectively. Further analysis revealed that ECMWF and CMA can reproduce the mid–high-latitude wave patterns associated with the intraseasonal variations in the EAWJ at lead times of 1–10 days, contributing to better predictions of the intraseasonal northward migration of the rainfall. Their ability to predict the tropical convection differed, with ECMWF more accurately reproducing the anomalous dipole tropical convection activities over the Indo-Pacific Warm Pool and the central-eastern Pacific 1–22 days in advance, and the characteristic that the convection eventually weakens over the maritime continent. This led to better predictions of the intraseasonal variations of the WPSH, giving the ECMWF model a higher forecasting skill for both periods of the extreme ARWC in 2021 compared to the CMA model.","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"1 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142816546","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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