1979-2017年江淮梅雨降水变化及一次典型事件特征分析  

Precipitation Changes of Jianghuai Meiyu from 1979 to 2017 and a Typical Event Feature Analysis

作　　者：任晓玥 王伟[1] 周可 REN Xiaoyue;WANG Wei;ZHOU Ke(College of Atmospheric Sciences,Chengdu University of Information Technology,Chengdu 610225,China;Weather Bureau of Yunnan Province,Kunming 650100,China)

机构地区：[1]成都信息工程大学大气科学学院,四川成都610225 [2]云南省气象信息中心,云南昆明650100

出　　处：《成都信息工程大学学报》2019年第6期632-639,共8页Journal of Chengdu University of Information Technology

基　　金：国家自然科学基金资助项目(41005034);公益性行业(气象)科研专项资助项目(GYHY201506001)

摘　　要：为了研究江淮梅雨的降水情况,采用了中国气象数据网提供的1979~2017年全国气象站点逐日降水资料,欧洲中心的再分析资料与Kaplan Extended的海温异常数据,对这39年里江淮梅雨的变化以及2016年梅雨具体的降水过程和环流情况进行了分析。结果表明:1979~2017年中有15年的梅雨降水量超过了平均值,其中降水量最大的年份为1996年。作为降水量第三大的2016年,梅雨期间有两次短期持续性强降水过程,降水空间分布呈现以湖北东部、江西南部附近最大值区域为中心,以长江为轴线,向南北方向降水量迅速减小,整个雨带呈现东西方向带状分布的特征。之后着重对两次强降水期间以及前后时期大气各层平均环流形势进行分析,结果显示150 hPa高度场上由南亚高压维持,高压北部有西风带,南亚高压随时间东移延伸至江淮地区上空,使该地区受到高层辐散气流影响,产生强烈的局地上升运动;500 hPa高度场上有西太平洋副热带高压的北移西伸,江淮地区上空的西南风气流输送的暖湿气体为降水提供了充足的水汽供应,并与南下的冷空气汇合利于锋生;700 hPa高度场上存在江淮切变线和低空急流,并有东移的西南涡,有利于强降水的发生。最后通过研究此次梅雨前期2015年秋季至2016年春季的海温情况,发现中东太平洋地区有明显的海温异常增暖现象,其中最显著的增暖区域在Niňo3区和Niňo1+2区范围内,是一次典型的东部型El Niňo事件,对后期江淮梅雨的降水十分有利。In order to research the precipitation of the Jianghuai Meiyu,1979-2017 daily precipitation data of national meteorological stations from China meteorological data network, ERA-Interim reanalysis data and Kaplan Extended sea surface temperature anomaly data are used to analyze the changes of Jianghuai Meiyu in the past 39 years and the specific precipitation process and circulation of Meiyu in 2016.The results show that there are 15 years? precipitation of Meiyu exceed the average from 1979 to 2017 and the year with the largest precipitation was 1996?, 2016 year has the third largest precipitation. there were two short-term persistent heavy precipitation processes during the Meiyu period., The area of maximum value nearby the Eastern Hubei and Southern Jiangxi is taken as center and the precipitation alongside the south-north direction declined rapidly when taken the Changjiang as axis according to the precipitation space distribution the whole rain belt presented the characteristics of east-west distribution. Then focus on the analysis of the average circulation situation in each layer of the atmosphere during the two heavy precipitation and in the period before and after, it is found the 150 hPa height field was maintained by the south Asian high pressure, and there was a westerly belt in the north of the high pressure. As the south Asian high pressure moved eastward over the Jianghuai region, the area was affected by the high-level divergent airflow and generated a strong local upward movement. At the height of 500 hPa, the western Pacific subtropical high pressure moved north and extended west, the warm and humid air transported by the southwest wind over the Jianghuai region provided sufficient water vapor supply for the precipitation and confluencing with the cold air from the north area was beneficial to the frontogenesis. There were Jianghuai shear line and low level jet stream in the 700 hPa height field, and there was a southwest vortex moving east, which was conducive to the occurrence of heavy precipi

关 键 词：江淮梅雨 南亚高压 环流形势 低空急流 降水情况 降水过程 锋生 江西南部 

分 类 号：P458[天文地球—大气科学及气象学]