{"title":"Impacts of early spring soil moisture over the Greater Mekong Subregion on the interannual variation of South China Sea summer monsoon onset","authors":"Sining Ling, Shu Gui, Jie Cao","doi":"10.1016/j.atmosres.2024.107768","DOIUrl":"10.1016/j.atmosres.2024.107768","url":null,"abstract":"<div><div>This study investigates the influence of early spring (March–April) soil moisture (SM) over the Greater Mekong Subregion (GMS) on the interannual variation of South China Sea summer monsoon (SCSSM) onset, using observational analyses and numerical experiments. It is found that when early spring SM over the GMS is wetter, westerly anomalies dominate the South China Sea, corresponding to an early onset of the SCSSM, and vice versa. The analyses of physical mechanism show that the positive anomalies of early spring SM decrease local surface air temperature by adjusting the surface latent heat flux and sensible heat flux. The persistence of anomalous ground cooling contributes to negative geopotential height anomalies in the middle troposphere, and further induces the eastward retreat of western North Pacific subtropical high in May. The anomalous cyclone over the South China Sea favors the early onset of SCSSM. The key physical processes linking the variability of early spring SM over the GMS and the following SCSSM onset are confirmed by the sensitivity experiments using a coupled atmosphere–land model (CAM6–CLM5). Specifically, the onset date of the SCSSM in the drier experiment is 11 days later than that in the wetter experiment. The present results have implications for the forecast of SCSSM onset.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"312 ","pages":"Article 107768"},"PeriodicalIF":4.5,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637421","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":"Tropical cyclone-induced rainfall variability and its implications for drought in Taiwan: Insights from 1981 to 2022","authors":"Trong-Hoang Vo , Yuei-An Liou","doi":"10.1016/j.atmosres.2024.107771","DOIUrl":"10.1016/j.atmosres.2024.107771","url":null,"abstract":"<div><div>This study analyzes the interplay between tropical cyclones (TCs) and drought in Taiwan over the period from 1981 to 2022, leveraging data from CHIRPS, FLDAS, IBTrACS, and Sentinel and Landsat satellite imagery. Our findings reveal a significant decline in TC-induced rainfall over the last decade, with a turning point in 2017. We establish a low to moderate positive correlation between TC-induced rainfall and subsequent spring soil moisture levels, with April exhibiting the strongest connection. This relationship strengthens in transitions from agricultural to forested areas. Additionally, our research identifies a robust correlation (<em>r</em> = 0.77) between TC-induced rainfall and reservoir water levels, underscoring the consistent link between TCs and hydrological drought. However, intriguing disparities emerge in water availability patterns. In 2007 and 2020, reservoirs maintained normal levels despite reduced typhoon rainfall in prior years. Conversely, in 2019, water shortages occurred despite typical TC-induced rainfall. These cases suggest that water availability is influenced by factors beyond TCs, including water demand, infrastructure, monsoon and spring rainfall, air temperature, and water management strategies. Furthermore, we uncover a symmetrical relationship between TCs and monsoon-induced rainfall, indicating their potential to balance reservoir water supply. Nevertheless, both TCs and the monsoon exhibit declining trends in the past decade, heightening the risk of spring season water scarcity in Taiwan. Effective water resource management demands consideration of natural and anthropogenic factors, encompassing land use changes, deforestation, production activities, water pollution, and policy strategies. These measures are essential to mitigate water scarcity and promote sustainability in Taiwan.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"312 ","pages":"Article 107771"},"PeriodicalIF":4.5,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637422","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}
Dilinuer Tuoliewubieke , Junqiang Yao , Weiyi Mao , Ping Chen , Liyun Ma , Jing Chen , Shujuan Li
{"title":"Dominant spring precipitation anomaly modes and circulation characteristics in the Tarim Basin, Central Asia","authors":"Dilinuer Tuoliewubieke , Junqiang Yao , Weiyi Mao , Ping Chen , Liyun Ma , Jing Chen , Shujuan Li","doi":"10.1016/j.atmosres.2024.107767","DOIUrl":"10.1016/j.atmosres.2024.107767","url":null,"abstract":"<div><div>Recently, extreme precipitation has occurred frequently in the Tarim Basin, which has a fragile ecological environment, arousing widespread concern. Using daily precipitation observations from 42 stations in the Tarim Basin during the spring of 1980–2021 and monthly circulation reanalysis data from the European Center for Medium-Range Weather Forecasts Reanalysis v5, as well as statistical analyses and physical diagnostic methods, this study investigated the abnormal modes and the evolution characteristics and differences in atmospheric circulation. The results show that the spring precipitation anomalies in the Tarim Basin can be divided into two independent precipitation modes: the first (EOF1) is a precipitation pattern that is uniform throughout the region and the second (EOF2) is an east–west inverse pattern. Thus, there are distinct differences in the atmospheric circulation characteristics responsible for abnormal spring precipitation modes in the basin. When the precipitation across the entire basin is consistently excessive, the 500 hPa geopotential height is affected by the negative phase of the North Atlantic Oscillation related circulation, and anomalous negative geopotential height at 500 hPa and anomalous cyclone at 700 hPa control the entire Tarim Basin, favoring anomalous upward motion, and western and southwestern water vapor transport. This leaves the Tarim Basin with a net water vapor budget and abnormally high atmospheric precipitable water. The opposite situation occurs when the precipitation across the entire basin is consistently lower than normal. When there is a west-to-east precipitation gradient, the western part of the Tarim Basin is affected by the anomalous cyclone while the eastern part is affected by the amomalous anticyclone, leading to the east-west discrepancy. The western region of the Tarim Basin is dominated by upward airflow, whereas the eastern region is dominated by downward airflow, providing dynamic conditions for the west-to-east precipitation gradient. Under the influence of anomalous water vapor transport from the southwest and water vapor convergence, water vapor conditions favorable for precipitation can occur. The net water vapor in the basin also exhibited an abnormal west-to-east transport pattern. Moreover, the atmospheric precipitable water demonstrated an inverse phase distribution under the EOF2 atmospheric precipitation mode in the Tarim Basin.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"313 ","pages":"Article 107767"},"PeriodicalIF":4.5,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637418","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}
Sandipan Paul , Priyank J. Sharma , Ramesh S.V. Teegavarapu
{"title":"Rain event detection and magnitude estimation during Indian summer monsoon: Comprehensive assessment of gridded precipitation datasets across hydroclimatically diverse regions","authors":"Sandipan Paul , Priyank J. Sharma , Ramesh S.V. Teegavarapu","doi":"10.1016/j.atmosres.2024.107761","DOIUrl":"10.1016/j.atmosres.2024.107761","url":null,"abstract":"<div><div>Accurate precipitation estimates are quintessential for hydrologic modeling and climate studies. Different gridded precipitation products are available in any region, and selecting the best one is essential for hydroclimatic modeling and analysis. In the current study, observation- (APHRODITE), reanalysis- (IMDAA, ERA5-Land, PGF), satellite-based (IMERG, CHIRPS, PERSIANN-CDR), and hybrid (MSWEP) gridded precipitation products with different spatial and temporal resolutions are evaluated using several continuous, categorical, graphical, and interval-based performance measures towards detecting Indian Summer Monsoon Rainfall (ISMR) events and estimating their magnitudes for the subcontinent of India, considering IMD gauge-based gridded data as reference product. We confine our analysis to the monsoon season (i.e., June to September), the principal rainy season in the Indian sub-continent. The dearth of data and limited rain gauge-based observations from non-uniform sparse monitoring networks across India necessitated grid-to-grid comparative evaluations instead of point-to-grid assessments. We propose a new ranking framework to determine the suitability of precipitation datasets for twenty-seven hydroclimatic regions comprising homogeneous rainfall zones, Köppen-Geiger climate zones, and major river basins. Results from the comprehensive evaluation suggest that (1) APHRODITE, MSWEP, and ERA5-Land best approximate precipitation event occurrences across India, (2) MSWEP and ERA5-Land are most suitable (highest rank) alternatives at the regional level, while APHRODITE is found to be next suitable dataset owing to its persistent dry bias, (3) CHIRPS and IMERG have reasonably lower rank score across India, (4) close agreement of examined datasets is noted over semi-arid and sub-humid regions (e.g., peninsular and central India), whereas ERA5-Land, IMDAA, and APHRODITE fail to detect and reproduce the intensity of the events along the west coast and northeastern India, (5) PGF and PERSIANN-CDR are the least situated datasets. Moreover, the present study provides a unique and innovative perspective to characterise the precipitation over a vast topographic, ecologic, and climatic gradient region like India.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"313 ","pages":"Article 107761"},"PeriodicalIF":4.5,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637419","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":"Intraseasonal relationship of winter temperatures in North America and warm sea surface temperatures in the Northeast Pacific","authors":"Yujing Zhang , Jian Shi , Yuxin Chen , Fei Huang","doi":"10.1016/j.atmosres.2024.107773","DOIUrl":"10.1016/j.atmosres.2024.107773","url":null,"abstract":"<div><div>Winter temperatures in the North America (NA) exhibit evident intraseasonal variation, which has become more pronounced under global climate change. In particular, the wintertime relationship between NA temperatures and long-lasting positive sea surface temperature anomalies (SSTAs) in the Northeast Pacific (NEP), known as warm blobs, has been hotly debated in recent years. However, their relationship on intraseasonal timescales remains unclear. Using reanalysis data and an Atmospheric General Circulation Model, this study reveals that the intraseasonal variation of atmospheric circulation is the primary factor to induce intraseasonal temperature anomalies in NA after classifying warm SSTA events based on their different evolutions. Moreover, the atmospheric circulation anomalies over the mid-to-high-latitude regions are in part contributed by the feedback of NEP warm SSTAs to the atmosphere. Specifically, for early-winter warm SSTA events (peaking in November), there are two intraseasonal reversals in geopotential height anomalies over the NEP and NA, corresponding to a “cold-warm-cold” temperature change in NA. However, for mid-winter warm SSTA events (peaking in January), the atmospheric circulation pattern is relatively stable, mainly characterized by a “west high-east low” dipole, associated with persistent cold anomalies in NA. Then, the role of warm SSTAs over the NEP in the intraseasonal temperature variation is generally verified by the numerical simulations. Hence, although the NEP warm SSTAs may not be the dominant driver of the intraseasonal variations of winter NA temperatures, we emphasize the implication of their evolutionary differences in reflecting the NA temperature variations, which contributes to better predictability.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"313 ","pages":"Article 107773"},"PeriodicalIF":4.5,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637423","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":"Combined effects of ocean-land processes on spring precipitation variability in Mongolian Plateau","authors":"QianJia Xie , XiaoJing Jia , XinHai Chen , Qifeng Qian","doi":"10.1016/j.atmosres.2024.107765","DOIUrl":"10.1016/j.atmosres.2024.107765","url":null,"abstract":"<div><div>The Mongolian Plateau hosts one of the world's most fragile ecosystems, characterized by high volatility and frequent natural disasters due to rapid climate change and human activities in recent decades. Frequent dust storms notably mark spring in this region. Through observational analysis and numerical modeling, this study investigates the impacts of comprehensive ocean and land processes—including sea surface temperature (SST) in the North Atlantic and Pacific Oceans, as well as Eurasian land conditions—on the interannual fluctuations of spring precipitation in the Mongolian Plateau (SPMP) from 1979 to 2020. The ocean-land processes involve: a tripole pattern of North Atlantic SST anomalies triggers an eastward-propagating continental-scale wave train; Increased snow cover in Central Asia induces significant anomalous low pressure through the albedo effect; El Niño-Southern Oscillation initiate a teleconnection pattern over the upstream region of the Indian-western Pacific Ocean. These anomalous ocean and land conditions interact with large-scale atmospheric circulations, altering dynamical and hydrological conditions around the Mongolian Plateau, thereby contributing to SPMP variation. Further corroboration from numerical model experiments supports the observational analysis results. The combined effects of multiple ocean-land factors effectively explain precipitation variability across extensive areas of the Mongolian Plateau. A regression model constructed using these land-ocean factors captures the time evolution of the SPMP well.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"313 ","pages":"Article 107765"},"PeriodicalIF":4.5,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637424","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}
Xiaokai Song , Tian Zhou , Yufei Wang , Xingran Li , Dongsheng Wu , Yonghong Gu , Zikai Lin , Sabur F. Abdullaev , Mansur O. Amonov
{"title":"Spatiotemporal evolution of dust over Tarim Basin under continuous clear-sky","authors":"Xiaokai Song , Tian Zhou , Yufei Wang , Xingran Li , Dongsheng Wu , Yonghong Gu , Zikai Lin , Sabur F. Abdullaev , Mansur O. Amonov","doi":"10.1016/j.atmosres.2024.107764","DOIUrl":"10.1016/j.atmosres.2024.107764","url":null,"abstract":"<div><div>The unique terrain and complex atmospheric boundary layer (ABL) processes result in a distinctive spatiotemporal distribution of dust in the Tarim Basin; however, this distribution remains unclear under continuous clear-sky conditions. In this study, 382 cases were selected to investigate the spatiotemporal evolution of dust and its potential mechanisms based on MERRA-2 and ERA5 reanalysis datasets combined with MODIS satellite observations during the warm seasons from 2000 to 2023. Taking the typical case of a completely cloudless on July 24–27, 2016, the dust aerosol optical depth (DAOD) at the margin of the Tarim Basin increased with time. The climatological characteristics showed a high DAOD in the northern, western, and southwestern regions and a relatively low DAOD in the central area. Nocturnal low-level jets dominated by northeasterly winds enhance the low-level westward airflow in weak anticyclonic systems, causing dust accumulation in the west and north of the basin. Vertical mixing within the ABL during the daytime increases dust loading in the residual layer, and these dust particles can ascend to high altitudes after breaking through the ABL by the vertical circulation. The dust loading at the lower level during the daytime was higher than that at night, whereas the opposite was true for the upper level. The downward airflow in the northwest slope of the Tibetan plateau weakens at night, leading to dust being uplifted to higher altitudes and transported outside the Tarim Basin by the westerlies. These results enhance our understanding of dust distribution and related mechanisms in Tarim Basin and support the development and utilization of climatic resources in this region.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"312 ","pages":"Article 107764"},"PeriodicalIF":4.5,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637453","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":"Reduction in Arctic sea ice amplifies the warming of the northern Indian Ocean","authors":"Xiaojing Li, Jie Zhang, Xinyu Fang, Xizi Rao","doi":"10.1016/j.atmosres.2024.107763","DOIUrl":"10.1016/j.atmosres.2024.107763","url":null,"abstract":"<div><div>The sea surface temperature (SST) in the tropical Indian Ocean(IO) has experienced rapid warming over the past 40 years. The reason for this phenomenon is still debated. Our study suggests that the decrease in Arctic sea ice during winter can influence the warming of SST in the Northern Indian Ocean (NIO) through three main pathway including atmospheric circulation, western Pacific SST and Tibet Plateau land. Firstly, the reduction of Arctic sea ice can trigger atmospheric teleconnection wave trains and circulation anomalies from the North Atlantic to the NIO, leading to anticyclone anomaly in the Bay of Bengal(BOB) that increases thermal contribution by radiation warming, as well as cyclonic anomalies in the Arabian Sea(AS) that increases dynamic contribution by warm current transport. Secondly, the reduction of Arctic sea ice can induce a wave train propagating from the Arctic through Eurasia to the western Pacific, resulting in anticyclone anomalies and SST rise in the South China Sea, thus enhancing the dynamic contribution of heat transfer through the Indonesian through flow(ITF). Thirdly,Arctic sea ice can enhances cross-equatorial flow by inducing warm surface temperature of the Tibetan Plateau.These three pathways will still exist until 2045 in future SSP245 emission scenarios.This study establishes a connection between the Arctic and the tropical IO, expanding our understanding of the relationship between these regions.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"312 ","pages":"Article 107763"},"PeriodicalIF":4.5,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593539","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}
Alugula Boyaj , Palash Sinha , U.C. Mohanty , V. Vinoj , Karumuri Ashok , Sahidul Islam , A. Kaginalkar , M. Khare
{"title":"Projected frequency of low to high-intensity rainfall events over India using bias-corrected CORDEX models","authors":"Alugula Boyaj , Palash Sinha , U.C. Mohanty , V. Vinoj , Karumuri Ashok , Sahidul Islam , A. Kaginalkar , M. Khare","doi":"10.1016/j.atmosres.2024.107760","DOIUrl":"10.1016/j.atmosres.2024.107760","url":null,"abstract":"<div><div>Heavy rainfall events and associated floods have emerged as one of the great threats to society that mainly manifested due the climate change. The Indian summer monsoon (ISM) contributes 80 % of annual rainfall and is characterized mainly by high-intensity rainfall events (HiREs) in the recent era. We investigated the spatiotemporal variability of HiREs from a climate change perspective by accessing the India Meteorological Department's (IMD) observed daily gridded rainfall dataset (0.25° × 0.25°) from 1961 to 2020 during the ISM season. Our observational analysis shows that the ISM total and the frequency of low- to high-intensity rainfall events have significantly decreased mostly over the central northeastern, Jammu and Kashmir, and some places in the northeastern and central parts of India. However, they have significantly increased over Gujarat, the northwestern, the Western Ghats, and the southern parts of India during the present climate period (1991–2020) compared to the past climate period (1961–1990). Furthermore, we explored the fidelity of five Coordinated Regional Climate Downscaling Experiments (CORDEX) Regional Climate Models (RCMs) in simulating the spatiotemporal variability of ISM total rainfall and the frequency of low- to high-intensity rainfall events over India during the historical (1976–2005) and future periods (2006–2100). All CORDEX RCMs overestimate the ISM total rainfall over India's heavy rainfall zones during the historical period by ∼10–30 % compared to IMD observations. To improve CORDEX RCM's skills in simulating the frequency of low- to high-intensity rainfall events, we employed a percentile-based bias correction technique. Compared to non-bias-corrected outputs from the RCMs, the quantile-bias-corrected method significantly enhanced the probability of detection rate (hit rate) in all studied models for extreme, heavy, and moderate rainfall events, excluding light rainfall events. Interestingly, the improvement is greater for extreme events, followed by heavy and moderate rainfall events. The composite hit rate of all the models shows 381 %, 146 %, and 44 % improvement for extreme, heavy, and moderate events, respectively. It is noticed that the CCCMA model performed better than the other four CORDEX models in capturing the spatial patterns of ISM total rainfall and the frequency of total extreme and heavy rainfall events over higher rainfall zones in India. Additionally, this study suggests that there will likely be no significant changes in ISM total rainfall over India in the future, but the frequency of total extreme and heavy rainfall events will most likely increase, while the frequency of moderate rainfall events will likely decrease mostly over southern parts of India in future projections.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"312 ","pages":"Article 107760"},"PeriodicalIF":4.5,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593542","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}
Linbo Wei , Lin Zhao , Zongyue Li , Yan Li , Qi Wen , Yuxia Ma
{"title":"Numerical simulation of circulation characteristics of orographic precipitation in Qilian Mountains, Northeastern Tibetan Plateau","authors":"Linbo Wei , Lin Zhao , Zongyue Li , Yan Li , Qi Wen , Yuxia Ma","doi":"10.1016/j.atmosres.2024.107762","DOIUrl":"10.1016/j.atmosres.2024.107762","url":null,"abstract":"<div><div>In order to clarify the synoptic meteorology and low-level circulation characteristics of orographic precipitation in northeastern Tibetan Plateau (referred as TP), numerical simulation of a precipitation case that happened in Qilian Mountains on August 12–13, 2019 was conducted using the Weather Research and Forecasting (WRF) model in this paper. The results show that WRF model can roughly capture the timing and location of the orographic precipitation. During the period, a weak trough and a weak ridge were found behind a large-scale trough at 500 hPa at the initial and continuation phases primarily due to the effect of complicated topography to provide a beneficial circulation background at high altitudes. The extinction of this circulation pattern and northwesterly after the large-scale trough leaded to the extinction of the precipitation.</div><div>In lower levels, warm advection from the south and cold advection from the north met over the precipitation region, resulting to a dividing temperature line tilting northeast from surface to high-altitude, which was crucial for instability and humidity, although no significant converging wind field near the surface suffering from the complex topography. In addition, the low-level jet, downslope flow and heating role at the basin bottom were also found to play important roles in the precipitation. The above analysis indicates that the precipitation was a result under the combined influence of the westerly circulation and the plateau monsoon circulation.</div></div>","PeriodicalId":8600,"journal":{"name":"Atmospheric Research","volume":"312 ","pages":"Article 107762"},"PeriodicalIF":4.5,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637425","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}