摘要
基于青藏高原低涡和切变线(简称高原低值系统)年鉴、国家气象站地面观测资料及ERA-Interim再分析资料,分析了高原低值系统多、少发年夏季高原地气温差变化的差异及其对我国降水的影响。结果表明:(1)高原夏季地气温差对高原低值系统的发生和移动有明显的影响。在低值系统频发区,多发年的地气温差明显比少发年高。(2)我国西部的青藏高原中部、东北部及西南地区在多发年降水偏多,高原南部和东南部则在少发年降水偏多;我国东部地区,多、少发年降水差异自南至北呈“+”、“-”、“+”、“-”、“+”的差值带分布特征,即华南、江淮流域、华北和东北地区降水在多发年偏多,江南地区和黄淮流域降水则在少发年偏多。(3)高原低值系统多、少发年夏季对流层的环流系统及相应垂直速度、水汽输送变化有明显差异,并影响青藏高原和我国降水的变化。在高原地区,多、少发年之间环流的差异是受高原东部和南部的气流辐合(辐散)场、相应的垂直运动差值上升(下沉)、水汽输送辐合(辐散)区域变化的影响;在东部地区,则是受南海到华南、长江流域、华北到东北为气旋(反气旋)环流系统及其间辐合(辐散)带变化的影响。
By using the Tibetan Plateau Vortex & Shear-Line(PVSL) yearbook,the ground observation station data of the National Meteorological Information Centre and the ERA-Interim reanalysis data,the difference of summer plateau ground-air temperature between multi-and less-years of PVSL and its impact on precipitation in China are analyzed.The results show that:(1) The difference of summer plateau ground-air temperature has a significant impact on the occurrence and movement of the PVSL.In the areas of the PVSL frequent occurrence,the ground-air temperature difference in multi-year is obviously higher than that in less-year.(2) More precipitation occurs in the central,northeastern and southwestern parts of the Tibetan Plateau in western China in multi-yearmore precipitation,while more precipitation occurs in the southern and southeastern parts of the plateau in less-year.From the south to the north in eastern China,the difference of precipitation in multi-and less-years is shown as “+”,“-”,“+”,“-”,“+”.In other words,the precipitations in South China,the Yangtze-Huaihe River Basin,North China and Northeast China are more in multi-year,while the precipitations in the Jiangnan region and the Huang-Huaihe River Basin are more in less-year.(3) There are obvious differences in the tropospheric circulation system and corresponding vertical velocities and water-vapor transportation in summer of multi-year and less-year of PVSL,which affect the precipitation changes in the Tibetan Plateau and China.In the Tibetan Plateau area,the difference of circulation system between multi-year and lessyear is affected by the wind field convergence(divergence) over the Eastern and Southern plateau as well as corresponding vertical velocity rise(sink) and water-vapor transportation convergence(divergence).In the eastern China,the difference is affected by the changes in the cyclonic(anticyclonic) circulation system and its convergence( divergence) zone from the South China Sea to South China,the Yangtze River Basin,North China to Northeast China.
作者
胡洁
巩远发
黄鹏
次丹卓玛
HU Jie;GONG Yuanfa;HUANG Peng;CIDAN Zhuoma(Climate Centre of Tibet Autonomous Region,Lhasa 850000,China;School of Atmospheric Sciences,Chengdu University of Information Technology,Chengdu 610025,China;Changdu Meteorological Service,Changdu 854000,China)
出处
《高原山地气象研究》
2022年第4期9-17,共9页
Plateau and Mountain Meteorology Research
基金
国家自然科学基金项目(41775079,U20A2097)。
关键词
高原低值系统
地气温差
降水
Plateau Vortex&Shear-Line(PVSL)
Ground-air temperature difference
Precipitation
