2006年云南省盛夏高温干旱成因分析

对2006年云南盛夏严重的高温干旱及其成因进行分析。结果表明：西太平洋副热带高压强度偏强,位置偏西、偏北,不利于将孟加拉湾等地的暖湿气流带到云南、四川等地,使这些地区7-8月降水明显偏少;亚欧地区经向环流偏弱,纬向环流偏强,中高纬地区大气环流以纬向环流占优势,不利于冷空气向南方地区输送;阿拉伯湾、孟加拉湾、南海及云南、四川等地的OLR值偏高,对流活动受到抑制,不利于水汽的输送及降雨的产生;850 hPa温度场上,云南多处于高温暖区内,7-8月无明显冷空气影响云南等都是形成高温干旱的重要原因。

CAUSE ANALYSIS OF HIGH TEMPERATURE AND DROUGHT IN 2006'S MIDSUMMER IN YUNNAN PROVINCE

According to the analysis of the heavy high temperature and drought of Yunnan Province in the mid- summer of 2006. The main causes that led to high temperature and drought in Yunnan were found that the position and intensity of the Western Pacific subtropical high at 500 hPa located to the west and north and stronger than av- erage. The water vapor from Bay of Bengal brought to Yunnan and Sichuan was inhibited. The meridional circula- tion was weaker and zonal circulation was stronger than normal in the area of Asia and Eurasia. More obvious lati- tudinal circulation at middle high latitudes. OLR is higher in Bay of Arab Bay of Bengal South sea of China Yunnan and Sichuan and the convective activity was weakened. Yunnan kept warmer area at 850 hPa temperature, and there was no cold air brought to Yunnan Province in July and August.