重庆秋季降水特征及大气环流异常分析

利用重庆1960-2006年秋季降水量计算了重庆地区秋季区域降水指数,采用相关与合成分析、线性趋势估计、Mann-Kendall突变检测方法和小波分析等统计诊断方法分析了重庆秋季降水变化特征及其与同期和前期大气环流的关系.结果表明:重庆秋季降水偏多、偏少年同期及前期中高纬度地区高度场距平都有明显的差异.前期冬季北太平洋中纬度地区对流层高度距平为正,加拿大西部对流层高度距平为负时,秋季重庆降水异常偏多,具有一定的预测意义.在此基础上定义了影响重庆地区秋季降水的前期因子.

Analysis of the characteristics of autumn precipitation in Chongqing and the related atmospheric circulation

Based on the precipitation in autumn from 1960 to 2006, the autumn precipitation indexes in Chongqing have been calculated. The characteristics of autumn precipitation change and the relationship between the autumn precipitation and the atmospheric circulation in autumn and the preceding winter have been analyzed by using linear correlation analysis,linear-trend analysis,Mann-Kendall method and Mexico-hat wavelet analysis. The results show that atmospheric circulation patterns in the middle-high latitudes in wet and dry years of autumn precipitation in Chongqing are different. When the height of the troposphere in the middle-high latitudes of north Pacific is the positive departure and the height of the troposphere in west Canada is the negative departure, autumn precipitation in Chongqing is more than normal. On the basis of the mentioned analysis the preceding factors of autumn precipitation in Chongqing have been defined.