西北地区东部持续性干旱大气环流分析

摘要

利用NCEP位势高度场资料及国家气候中心160站的月平均降水资料,对西北地区东部(32.5°~41.0°N、100.0°~112.5°E)持续性干旱事件有关的大气环流进行了分析.结果表明,持续性干旱发生时期合成的500 hPa异常位势高度场在欧亚大陆上空的环流形势基本为两槽一脊,欧洲及渤海、黄海及周围地区为槽,西北地区东部位于脊前;渤海、黄海及周围地区上空对应负异常是持续性干旱发生的典型环流场特征,易造成研究区域干旱事件的发生.%The atmospheric circulation in the eastern part of the Northwest China (32.5°-41.0°N, 100.0°-112.5°E) was analyzed by u-sing the NCEP geopotential height field data and the monthly average precipitation data of the National Climate Center 160 stations.The results showed that in the conditions of combining the abnormal height field of the drought years ,500 hPa circulation pattern of the entire Eurasian continent was mainly composed of two troughs and one ridge, Europe and the Bohai Sea, the Yellow Sea and the surrounding area were the trough,and the eastern part of the Northwest territories lied before the ridge.The negative anomalies above the Bohai Sea, the Yellow Sea and the surrounding areas were typical circulation field characteristics of persistent drought, which could lead to the occurrence of drought events in the study area.