【摘要】 1999—2002年云南处于雨季偏早、5月雨量偏多的气候背景下,2002年雨季连续第四年偏早,这种气候异常较罕见。利用雨季开始期资料,分析了云南雨季开始期变化的年代际特征。还对应分析了雨季开始偏早年及偏晚年1月及5月100、500hPa及SLP场距平合成场,并与2002年进行了比较,得到了一些对预测云南雨季开始期有指导性的结论。2002年云南雨季偏早开始与索马里急流建立,高层中低纬环流出现"突变"有直接原因。更多还原

【Abstract】 The onset time in rainy season of Yunnan was earlier, and May precipitation was also more than normal. It was very exceptionally anomalous climate that the onset time in rainy season of Yunnan in continuous fourth years was earlier in 2002. We used the onset time data in rainy season of Yunnan to analyze its interdecadal change characteristics. In addition, 100, 500 hPa and SLP anomalous fields in January and May were analyzed in earlier and latter years of rainy season onset time. Comparing with the circulations in 2002, some directive results of predicting onset time in rainy season of Yunnan were obtained. There were directive relations between the earlier onset time of Yunnan’s rainy season in 2002and building of Somali jet, which is direct reason for the occurring abrupt change of the upper level mid and lowlatitude circulations.更多还原