Atmospheric Research最新文献

{"title":"Historical and future projections of southwest monsoon rainfall extremes: a comprehensive study using CMIP6 simulations","authors":"Hamza Varikoden, V.H. Jamshadali, Catherine George, T. Reshma, R. Vishnu","doi":"10.1016/j.atmosres.2024.107870","DOIUrl":"https://doi.org/10.1016/j.atmosres.2024.107870","url":null,"abstract":"The South Asian regions frequently encounter extreme rainfall events (EREs) during the summer monsoon season, causing property damage, environmental harm, and fatalities. Therefore, it is essential to comprehend how these events are evolving and may change in the future, particularly for developing countries like India. This study utilised selected models from the Coupled Model Intercomparison Project Phase 6 (CMIP6) to evaluate the intensity and contribution of EREs to seasonal rainfall during the historical period (1950–2014), as well as to anticipate the variability of extremes in the future period (2015–2100) during the summer monsoon period. Compared to observational rainfall data from the Climatic Research Unit, the selected models showed similar spatial patterns for mean and extreme rainfall in the historical period with regional biases across CMIP6 selected models, mainly in the monsoonal regions such as the west coast, central India, the Himalayas and its foothills, and the northeastern regions. Four EC-Earth models accurately projected mean and extreme rainfall for central India, the southern west coast, and the western Himalayan regions, while NorESM slightly overestimated central India and underestimated) west coast extremes. Moreover, the selected models are not adequate to realistically capture the extremes in northeastern and Myanmar coastal areas. Future scenarios predict significant changes in extreme rainfall over central India and the rain shadow regions of southeast India. The increased ERE in the northern regions of the west coast and southwestern regions of central India could lead to increased vulnerabilities in the area, especially in higher forcing scenarios. Moreover, the zone of extreme rainfall is projected the expansion of the rain shadow regions to the leeward side of the Western Ghats, particularly in the SSP5–8.5 scenario.","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"11 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867581","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}

{"title":"Simulating rainfall during thunderstorm events: Insights into cloud-to-rain microphysical processes over the Indian subcontinent","authors":"Moumita Bhowmik, Anupam Hazra","doi":"10.1016/j.atmosres.2024.107859","DOIUrl":"https://doi.org/10.1016/j.atmosres.2024.107859","url":null,"abstract":"We investigated the performance of mass transfer from cloud water to rainwater, commonly referred to as ‘autoconversion’, in cloud microphysical schemes within high-resolution numerical models, such as the Weather Research and Forecasting Model (WRF). The proper choice of autoconversion rate in the numerical model is crucial for droplet growth and conversion rates to form precipitation. The liquid water content and cloud properties, varying from shallow to convective clouds, are highly sensitive to autoconversion rates, and their sensitivity is closely linked with model biases. A parcel-bin model guided by observations can provide significant insights for selecting a more suitable suite of autoconversion rates for the forecasting model. The parcel-bin model is important for the explicit representation of hydrometeors population and calculating microphysical process rates. We calculated drop size distribution, relative dispersion, diffusion growth rate coefficient, and autoconversion rates for two environmental conditions using a small-scale model based on in situ airborne measurement data from the Cloud-Aerosol Interaction and Precipitation Enhancement Experiment (CAIPEEX) over the Indian subcontinent. We evaluated four different (Kessler, KES; Liu-Daum, LD; Khairoutdinov-Kogan, KK; Lee-Baik, LB) autoconversion rates in the WRF model for simulating two thunderstorm events over India. The LD, LB and KK autoconversion rates exhibited closer performance and demonstrated a better probability distribution of raindrop size and precipitation compared to KES. The present study highlights the importance of proper choice of autoconversion rates in numerical weather prediction models.","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"26 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867584","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}

{"title":"Field validation of brown carbon absorption dependence on acidity and aerosol liquid water content","authors":"Prerna Thapliyal, Ashish Soni, Tarun Gupta","doi":"10.1016/j.atmosres.2024.107868","DOIUrl":"https://doi.org/10.1016/j.atmosres.2024.107868","url":null,"abstract":"Brown Carbon (BrC) is an organic component of aerosols with light-absorbing characteristics that have crucial consequences in atmospheric warming and the climate system, yet it carries significant uncertainty. This uncertainty is due to its non-static optical properties which provide a significant challenge in the measurement of the perturbation caused by them in the Earth radiation budget. The unpredictability in optical properties is because of the continuous formation of Secondary BrC and decay of existing BrC influenced by various physicochemical and meteorological factors in the ambient atmosphere. The dynamic behaviour of these chromophores can be impacted by the aerosol liquid water content (ALWC) and atmospheric acidity via influencing its atmospheric chemistry of formation and decay. The objective of this research is to investigate how the ALWC and acidity in terms of pH affect the BrC optical properties in the rarely examined Eastern part of India during extreme winters. Utilizing a thermal-optical carbon analyzer, the optical characteristics of BrC were estimated. The ISORROPIA II, thermodynamic model was employed to simulate ALWC and aerosol pH, yielding a mean pH value of 3.30 ± 0.16 for the study duration. The study provides the first in-field evidence of a linear increase of absorption coefficient with increasing pH or decreasing aerosol acidity in the ambient atmosphere. A 39.6 Mm<ce:sup loc=\"post\">−1</ce:sup> increase in absorption coefficient per unit increase in pH, shows that aerosol pH is one of the decisive elements influencing BrC chemistry. The results also showed the inverse relation of the absorption coefficient with ALWC. The findings indicate the sensitivity of BrC chemistry towards aerosol acidity and ALWC in the ambient atmosphere and its importance while evaluating BrC absorption.","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"16 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142816535","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}

{"title":"Aerosol optical depth over Northeastern Brazil: A multi-platform intercomparison study","authors":"Gabriel Bonow Münchow, Aline Macedo de Oliveira, Ediclê De Souza Fernandes Duarte, Daniel Camilo Fortunato dos Santos Oliveira, Bárbara Marinho Araujo, Nilton Manuel Évora do Rosário, Judith Johanna Hoelzemann","doi":"10.1016/j.atmosres.2024.107864","DOIUrl":"https://doi.org/10.1016/j.atmosres.2024.107864","url":null,"abstract":"The atmosphere over the Northeastern region of Brazil (NEB) contains a variety of different aerosol types: marine, soil dust, biomass burning, urban pollution, as well as mixed species. However, very few reliable information on aerosols is available for the region. Satellite data provides spatial and temporal coverage in places with low density ground-based observational networks, with Aerosol Optical Depth (AOD) products as most important information on the atmospheric aerosol load. To find out how different AOD products from satellites behave over the NEB region we compared AOD at 550 nm from MODIS retrievals aboard both NASA's Terra and Aqua satellites, and ground-based derived AOD 550 nm from the two Aerosol Robotic Network (AERONET) sites in the region, located in cities of Petrolina and Natal, between 2015 and 2018. We based our analysis on the following MODIS AOD retrievals products: Dark Target (DT), Deep Blue (DB), the combined product (DTDB), DT 3 km resolution product (MxD3k) and MAIAC at 1 km resolution. Additionally, we used AOD from MERRA2 reanalysis for another comparison that may provide additional insight on which products perform best over the region. We also analyze and compare the seasonality of the AOD products to the four biomes of NEB, which are Amazon rainforest, Atlantic Forest, Cerrado and Caatinga (wooded savannah-like) biomes. Petrolina is located in the NEB largest biome, the Caatinga, while Natal is a coastal city in the Atlantic Forest. The results show that DB yields the best results for the Petrolina site. The analyses also show that in all biomes the AOD monthly averages decrease during austral autumn and winter and increase during spring and summer. The compared products show some differences in AOD, even though with similar patterns. MAIAC and DB show very similar values in all four biomes throughout the year, recommending the use of DB and MAIAC for studies in the Caatinga region.","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"9 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142816538","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}

{"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}

{"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}

{"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}

{"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}

{"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}

{"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}