为了分析云南春季低温的前期环流特征,本文利用各县站的逐日气温和500 hPa月平均高度的格点资料,分析结果表明,春季低温年前冬10~20 d振荡活跃,1月份环流特征与正常年相比有明显不同。研究还发现,用纬向高度梯度结果代替高度场作春季低温分析预报,更有物理意义。

Spring lower temperature of Yunnan is defined as cold and frost of late spring that occurs often from February to April.Studies show that activities of 10~20 days oscillation during microtherm are protruding and circulation features in preeceding winter differ from normal years.Also using zonal gradient of geopotential height is better than height for temperature forecasting and analyzing.