热带气象学报2013，Vol.29Issue(1)：99-105,7.DOI:10.3969/j.issn.1004-4965.2013.01.012
江南春雨的两个阶段及其降水性质
TWO STAGES OF SPRING PERSISTENT RAINS OVER SOUTHEASTERN CHINA AND THE NATURE OF PRECIPITATIONS
摘要
Abstract
Based on 1970-2009 NCEP/NCAR pentad reanalysis dataset and 1979-2008 CMAP pentad rainfall dataset, seasonal variation features of spring persistent rains (SPR) in Southeastern China (110～120 °E, 23～30 °N) from the 1st to 27th pentad are investigated. By the technique of moving-t test it is revealed that SPR increases abruptly at the 10th and 16th pentads, reaching the 99% significance level. Therefore, the 10th pentad can be regarded as the onset date of SPR. SPR can be divided into two stages: the first from 10th to 15th pentad, and the second from 16th to 27th pentad. Accompanied with the abrupt increase in rainfall, there exists rapid enhancement in southwesterly in the southeastern flank of the Tibetan Plateau, which happens 1 ～ 2 pentads ahead of SPR. In its second stage of SPR, a winter-pattern Hadley cell along East Asia disappears, and the ascending motion can reach up to 200 hPa over Southeastern China, being associated with the eastward pressure gradients and high convective precipitation rates as well as convective instability, all indicating that the rainfall in its second stage of SPR is actually subtropical monsoon rainfall in nature.关键词
气候学/江南春雨/副热带季风降水/降水性质/滑动t检验Key words
climatology/ spring persistent rains in southeastern China/ subtropical monsoon rainfall/ nature of precipitations/ moving-t test分类
天文与地球科学引用本文复制引用
刘宣飞,袁旭..江南春雨的两个阶段及其降水性质[J].热带气象学报,2013,29(1):99-105,7.基金项目
江苏高校优秀学科建设工程项目(PAPD) （PAPD）
国家自然科学基金重点项目(40633018)共同资助 （40633018）
