川渝地区夏季高温干旱变化特征及其异常年环流形势分析  

Changing Characteristics of High Temperature and Drought of Sichuan-Chongqing Regions in Summer and Its Analysis of Circulation Patterns in Anomalous Years

作　　者：刘晓冉[1] 程炳岩[1] 杨茜[2] 张天宇[1] 邓北胜[3] 

机构地区：[1]重庆市气候中心,重庆401147 [2]重庆市人工影响天气办公室,重庆401147 [3]中国气象局培训中心,北京100081

出　　处：《高原气象》2009年第2期306-313,共8页Plateau Meteorology

基　　金：中国气象局气候变化专项“川渝地区极端高温干旱发生规律及成因研究”(CCSF2007-24);中国气象局“三峡库区气候监测、预警、评估业务运行和改进”业务建设项目;重庆市科技攻关项目(CSTC2008AB0015);重庆市气象局科技计划项目(zl-200813)共同资助

摘　　要：分析了川渝地区夏季高温日数时间演变特征及其异常年份的环流形势。结果表明,川渝地区高温日数在20世纪50年代到70年代总体偏多,1979年是由多到少的突变年,80年代高温日数明显偏少,90年代以后又有增多趋势。川渝地区夏季高温酷暑年和凉夏年的环流形势存在着明显的差异。酷暑年,我国南海北部对流增强,使得西太平洋副热带高压偏北,乌拉尔山和鄂霍次克海地区无持续性阻塞高压,同时东亚大槽变浅,青藏高原上升运动减弱。850 hPa距平风场上,川渝地区以南被东北距平风控制,以北被正南距平风控制,这种环流形势配合有利于川渝地区夏季高温干旱的发生、发展。前期春季OLR场变化特征可为川渝地区夏季高温干旱的预测提供一定的参考依据。The changing characteristics of the high temperature days of Sichuan-Chongqing regions in summer and its circulation patterns in anomalous years is analyzed in this paper. The results show that the high temperature days was more than normal from 1950＇s to 1970＇s, and was obvoursly less than norreal in 1980＇s after the abrupt change from many to few in 1979, then had a increasing trend after 1990＇s. The circulation patterns have the obvious difference between in hot summer years and in cool summer years. In hot summer years, the strengthening of the convection over northern of the South China Sea leads to the West Pacific Subtropical High shifting northward, and there aren＇t continuing block high in Okhotsk and Ural regions, and the East Asian Trough become weak, and the updraft over the Tibetan Plateau is weak. There are northeast anomalous stream in the south of Sichuan-Chongqing reigion and south anomalous stream in the north of Sichuan-Chongqing regions. These circulation patterns are advantageous to the genesis and development of the high temperature and drought in Sichuan-Chongqing regions. The previous OLR field in spring may offer some reference bases for predicting the high temperature and drought in Sichuan-Chongqing regions.

关 键 词：川渝地区 高温 环流形势 

分 类 号：P434[天文地球—大气科学及气象学]