重庆地区秋季连阴雨气候特征及前兆信号分析

根据1961—2012年重庆地区34个气象观测站的逐日降水资料、NCEP/NCAR再分析数据集中的高度场格点资料和NOAA的海温逐月资料,分析了重庆地区秋季连阴雨的气候特征、气候背景与前兆信号.结果表明:近52年来重庆地区秋季连阴雨频数呈线性增多趋势.重庆地区秋季连阴雨偏多(偏少)同期环流对应乌拉尔山地区高度场偏低(高),欧亚中高纬度地区盛行经向(纬向)环流,赤道东太平洋区域海温偏低(偏高).前期春季、夏季孟加拉湾地区、我国南海地区500hPa高度场、赤道中东太平洋地区海温,特别是Nio3.4区的海温异常变化是重庆地区秋季连阴雨出现异常偏多(少)值得关注的前兆信号.

On Analysis of Precursors and Climatic Characteristics of Continuous Autumn Rain in Chongqing

In this paper ,the climate characteristics ,background and previous signals of continuous autumn rain in Chongqing have been studied based on height field from NCEP/NCAR ,monthly SST from NOAA and daily precipitation observed by 34 meteorological stations in Chongqing from 1961 to 2012 .T he results are as follow s :T he frequency of continuous autumn rain in Chongqing in recent 52 years has been in-creased .The more(less) continuous autumn rain corresponds to lower (higher) 500hPa height field over U-ral mountain area ,prevailing meridional (zonal) circulation in Eurasia high-mid latitudes and lower (high-er) SST in the equatorial east Pacific .The 500hPa height field in the bay of Bengal and South China Sea and SST in the equatorial central eastern Pacific especially in Ni?o 3 .4 in previous spring and summer are important previous signals of abnormal continuous autumn rain in Chongqing .