2003年云南夏季罕见高温干旱的诊断研究

2003年夏季云南出现了历史上罕见的大范围异常高温干旱天气，是自1961年以来云南最严重的夏季高温干旱天气之一，影响范围、持续时间及危害程度仅次于1983年。是20世纪80年代中期云南进入气温偏暖期后的一次夏季极端气候事件，打破多项历史纪录。利用高度、OLR、TBB等资料对此次气候灾害过程进行了诊断分析。发现西太平洋副热带高压持续稳定且偏强偏西，季风低压偏弱偏西，云南TBB值偏高，降水云系较少，OLR值偏高，对流活动抑制，云南正好处于东、西两个垂直环流圈的下沉气流控制区是形成高温干旱的主要原因。

Diagnosis of High Temperature and Drought Event in Summer 2003 in Yunnan

There was a heavy high temperature and drought event and disasters in a large area of Yunnan Province in the summer of 2003, it is one of the heaviest ones in Yunnan since 1961, its influencing area, sustaining duration and harm extent, is the second place except 1983. It is a summer extreme climate event since the mid 1980s during which Yunnan entered a warming phase. The summer drought disaster has been diagnosed by using data of height fields at 500hPa, Outgoing Longwave Radiation (OLR) and Temperature of Black Body(TBB) at cloud top. The main causes that lead to the persisting high temperature and drought event in Yunnan are found that the position and intensity of the Western Pacific subtropical high at 500hPa consistently located to the west and stronger than average and the monsoon depression also located to the west and weaker than average respectively. TBB and OLR values over Yunnan are greater than the average. Rainfall cloud system is seldom, and the convective activities is inhibition.