夏季北极海冰激发的500hPa遥相关型

本文应用统计方法,分析7月、8月北极海冰与北半球500hPa位势高度场的相关场,7月、8月500hPa基点相关图,多冰年与少冰年的1000—500hPa厚度差图等,得到如下结论: 夏季极冰冷源的存在,可激发北半球大气产生遥相关型,这种遥相关型可以看成二维Rossby波列,具有相当正压结构,在西风带中沿着固定的波导自高纬向低纬分布,从而影响北美的环流和天气。表现为极冰偏多年份,极涡加强而偏心,加拿大高压脊和北美大槽亦同时加强;反之,极冰偏少年份,上述系统均减弱。

Teleconnection Pattern between the Arctic Ice Area and the 500 hPa Geopotential Height Field during the Northern Hemispheric Summer

In this paper, the correlation field between the Arctic ice area and 500 hPa geopotential height field, the one-point correlation maps at 500 hPa, and the 1000-500 hPa thickness difference chart between the strongest arctic ice year and the weakest year for July and August (etc.)are analyzed.According to the foregoing statistical discussion, it may be noted: the arctic ice cold source in summer can be forcing the teleconnection pattern in the northern hemispheric atmosphere. The teleconnection pattern has two-dimensional Rossby wave train and equivalent barotropic structure.The centers of action in the teleconnection pattern can across the westerly jet and into the subtropics, but they only exist in the westerly belt.The teleconnectin pattern effects the atmospheric circulation and weather showing the polar ice being excessive, the polar low pressure being stengthened, the Canada ridge and the Northern American trough being strengthened too, and vice versa.