“三江源”夏季降水异常与大气环流异常的关系  

Analysis of Summer Precipitation Anomaly and Atmospheric Circulation in "Sanjiangyuan" Region

作　　者：刘彩红[1,2] 朱西德[1] 石顺吉[2] 徐明[2] 

机构地区：[1]青海省气象局气候中心,西宁810001 [2]南京信息工程大学

出　　处：《气象》2009年第7期39-45,共7页Meteorological Monthly

摘　　要：利用三江源地区14个站1961-2005年逐月降水资料，对全区近45年夏季降水异常的时空特征及与大气环流异常的关系进行了分析。结果表明，近45年来，三江源地区的夏季降水量具有良好的空间一致性，总体呈微弱的减少趋势，减少幅度为9mm／45a；三江源地区经历了5个干、湿交替的阶段，存在较明显的准2年、准4-6年的振荡周期，自1980年代中期后12-14年左右的周期信号较强；1968、1979及1986年是3个明显的气候突变点，小波分析结果与降水序列大-小-大-小-大的变化趋势及突变检验存在良好的对应关系。环流分析表明，三江源地区夏季旱、涝年份的大气环流配置形势在高度距平场、风场和温度场均呈反向变化，可作为强信号，对三江源夏季降水的异常预测起指示作用。The spatial and temporal features and circulation characteristics of summer precipitation anomaly in Sanjiangyuan are investigated on the basis of the monthly rainfall data at 14 stations from 1961 to 2005. The results show that the spatial distribution of summer precipitation has a good coherence in Sanjiangyuan, and on the whole has decreasing trend in the last 45 years. In addition, Morlet wavelet analysis indicates that there were quasi-two-year, quasi-four-to-six-year periodic oscillations in the summer precipitation, and three sudden changes in the years of 1968, 1979 and 1986 respectively. The above results indicate that the wet/dry years of climate inSanjiangyuan are closly related with the height field, temperature field, and wind field, the relations can obviously be as factors for precipitation＇s forecast.

关 键 词：三江源 夏季降水 异常特征 大气环流 

分 类 号：P426.616[天文地球—大气科学及气象学] P434