青藏高原低涡的活动特征和敏感区识别及其与陆面的关联分析研究  

Characteristics of Qinghai-Xizang Plateau Vortex Activities and Identification of Sensitive Areas:A Study on Its Correlation with the Land Surface

作　　者：李世园 吕少宁 文军 LI Shiyuan;LÜShaoning;WEN Jun(Department of Atmospheric and Oceanic Sciences/Institute of Atmospheric Sciences,Fudan University,Shanghai 200438,China;School of Atmospheric Sciences,Chengdu University of Information Technology/Plateau Atmosphere and Environment Key Laboratory of Sichuan Province,Chengdu 610225,Sichuan,China)

机构地区：[1]复旦大学大气与海洋科学系/大气科学研究院,上海200438 [2]成都信息工程大学大气科学学院/高原大气与环境四川省重点实验室,四川成都610225

出　　处：《高原气象》2024年第3期529-548,共20页Plateau Meteorology

基　　金：国家自然科学基金项目(42075150);上海市科委自然科学计划项目(21ZR1405500)。

摘　　要：青藏高原低涡是夏季青藏高原边界层内产生的中尺度低压涡旋系统,对高原天气及其周边地区降水有重要影响。本文利用由客观识别法得到的高原低涡数据集以及ERA5-land再分析资料,通过相关分析、回归分析、贝叶斯时间序列分析算法和概率统计等方法,对1950-2021年高原低涡的活动特征进行了统计和分析,根据高原低涡的路径及强度划定了高原低涡活动的敏感区,并分析了不同陆面参量与高原低涡的联系。结果表明,高原低涡的年总个数和年总持续时间都呈显著增加趋势(置信度95%),气候倾向率分别为0.16个·a^(-1)和1.25 h·a^(-1);高原低涡活跃期(5-8月)总个数和总持续时间的增加趋势不显著;高原低涡活动的敏感区位于藏北高原北侧、可可西里山脉附近,与青藏高原中西部的主要山脉相对应;敏感区内的地表潜热、地表长波辐射以及地表0~7 cm土壤湿度与高原低涡个数和持续时间呈正相关,而地表感热与高原低涡个数和持续时间呈负相关;进一步发现当时间尺度为年际变化时,高原低涡与降水的变化相对一致,而在日尺度上,地表感热主要在敏感区及其以东地区与低涡个数、持续时间和强度呈正相关,其中以5月和6月最为显著。本研究中的结论为进一步分析高原低涡敏感区内的陆-气相互作用机理,以及高原低涡数值模拟和数据同化研究提供理论依据。The Qinghai-Xizang Plateau Vortex is a mesoscale low-pressure vortex system generated within the boundary layer of the Qinghai-Xizang plateau in summer,which not only has an important influence on the weather patterns and precipitation dynamics across the plateau,but also profoundly impacts the surrounding regions.In this study,the database of the plateau vortex obtained from an objective analysis method,along with ERA5-land reanalysis data,was utilized to conduct a comprehensive statistical and analytical investigation of the vortex's activity from 1950 to 2021.Various analytical methods,including correlation analysis,regression analysis,Bayesian time series analysis algorithm,and probability statistics were used.Furthermore,the intensity and path of the plateau vortex during the years 1950 and 2021 were specifically examined to identify the areas most sensitive to its activity during this time span.Results reveal a noteworthy increasing trend(at a 95%confidence level)in both the annual number and duration of the plateau vortex,with climate tendency rates of 0.16·a^(-1) and 1.25 h·a^(-1),respectively.However,the growing trend for the total number and duration of the plateau vortex during the active period(May to August)is not statistically significant.The sensitive areas that affect the activity of the plateau vortex are located on the north side of the northern Qinghai-Xizang Plateau and near the Hoh Xil Mountains,corresponding to the main mountains in the central and western Qinghai-Xizang Plateau.Furthermore,the study investigates the relationship between land surface parameters and the vortex's characteristics,showing positive correlations between latent heat,surface longwave radiation,and surface soil moisture(0~7 cm)with the number and duration of the plateau vortex.Conversely,sensible heat exhibits a negative correlation,it is further found that the plateau vortex is relatively consistent with precipitation when the time scale of the study is inter-annual,while on the daily scale,the sensible heat is po

关 键 词：青藏高原 高原低涡 陆-气相互作用 

分 类 号：P466[天文地球—大气科学及气象学]