北半球冬季大气环流变化对中国汛期雨带类型分布的影响

 基于1951～2001年1～5月500hPa高度场资料,研究了前期大气环流与中国汛期雨带类型分布的关系.通过分析前期各雨带类型对应的距平合成场和格点样本平均值显著性检验图,以及各雨带类型相应的前期大气环流特征.指出1～2月500hPa层次上,大气环流明显的表现为大尺度分布特征,而3～5月的大尺度分布特征不明显.这表明冬季(1～2月)各雨带类型的显著性关键区的大气环流异常是影响中国汛期雨带类型分布的一个重要因素.从而提出了一些预报线索,可供夏季我国大范围旱涝趋势的长期预报参考.

Influence of winter atmospheric circulation change on principal rain fall patterns distribution in flood season over China

The relationships between summer principal rainfall patterns of China and winter (January to May) atmospheric circulation were analyzed by with 500?hPa high field and rain belt types data from 1951—2001.Through analyzing corresponding anomaly composite on 500?hPa and grid sample mean significance test,result winter atmospheric circulation characteristics for rain belt patterns were discussed.The results indicated that the atmospheric circulation from Jan.to Feb.is abnormalon large scales;but not for those from Mar.to May.These results provide some clues for forecasting summer rairfall in China.It is obvious that an important factor causing different principal rainfall belt distribution is sustained anomaly of large space and relatively long time scales of atmospheric circulation for from Jan.to Feb.in 500?hPa height field,but not for from Mar.to May,which advances some prediction clues towards forecasting summer rainfall in China.