西藏地区近几十年的增湿效应研究  

Moistening Effect Analyses in Tibet in Recent Several Decades

作　　者：罗布[1] 卓嘎[1] 赤曲[2] 

机构地区：[1]西藏高原大气环境科学研究所,西藏拉萨850000 [2]西藏自治区气象局,西藏拉萨850000

出　　处：《高原气象》2009年第1期72-76,共5页Plateau Meteorology

基　　金：成都高原气象开放实验室基金课题;中国气象局2006年气候专项项目(CCSF2006-24)共同资助

摘　　要：利用1955—2000年西藏6个地面观测站的46年连续观测资料,分析了近几十年西藏自治区部分地区气温、降水及水汽压变化特征,并利用第二类热成风螺旋度解释气温与降水的关系。结果表明:西藏近几十年平均气温呈显著的上升趋势,尤其是20世纪90年代以来更为显著(10年上升了0.32℃);全区降水量也有增多趋势;1955—1964年西藏地区气温升高时,第二类热成风螺旋度上升,导致降水量同时增多。1965—1981年气温、降水和第二类热成风螺旋度的变化幅度均较小。1982—2000年气温显著上升时,第二类热成风螺旋度上升,引起湿旋转作用加强,温度扰动加强,从而进一步加速大气中的水汽凝结,形成更多的降水;与此同时,地面蒸发量却减少,导致地表水增加,引发更多的地质灾害,造成更大的经济损失。Based on the observational data at six stations of Tibet from 1955 to 2000, the variation features of temperature, precipitation and water vapor in the recent several decades are analyzed. The second thermal wind helicity is also used to release the relation between temperature and precipitation. The results show that the temperature of Tibet has a significant increasing trend in the recent several decades, especially for 1990＇s and the annual average temperature rise 0.32℃ for this decade. The precipitation is also increased trend. The increase of temperature and second thermal wind helicity from 1955 to 1964 leads to the increase of precipitation. Whereas the changes of temperature, precipitation and second thermal wind helicity from 1965 to 1981 are not obvious, and precipitation is actually increased when temperature and second thermal wind helieity are increased from 1982 to 2000. Furthermore, it indicates that climatic warming has induced the raise of second thermal wind helicity and moistening rotation effect, the strength of temperature disturbance which lead to condensation of more and more water vapor, and then much water falls to the ground. At the same time, the water in surface ground is increased while the evaporation is decreased, which has caused much flood and more mountain landslides as well as costs.

关 键 词：西藏 气候变暖 第二类热成风螺旋度 湿旋转效应 

分 类 号：P457.6[天文地球—大气科学及气象学]