北半球50hPa环流异常与厄尔尼诺/反厄尔尼诺事件

本文对近三十年来的厄尔尼诺和反厄尔尼诺事件与北半球50hPa高度距平场的变化进行了分析。结果表明,厄尔尼诺发生的前冬(前一年11月至当年1月,下同),500hPa高度场的距平分布为:在极地附近地区是负距平;中纬地区除北美洲上空是弱负距平外,其余地区是正距平;30°N以南的低纬地区为负距平。反厄尔尼诺出现的前冬,500hPa高度场的距平分布为附近地区是正距平;中纬地区北美洲上空是弱正距平,其余地区为负距平;30°N以南的低纬地区为正距平。此外,厄尔尼诺和反厄尔尼诺事件发生的前冬,50hPa高度距平场的变化比50hPa其它各月高度距平场的变化以及500hPa高度距平场的变化都大。且前冬50hPa高度距平场的变化对厄尔尼诺和反厄尔尼诺事件的发生具有明显的指示意义。

THE ANALYSIS OF THE CORRELATION BETWEEN NORTHERN HEMISPHERE 50HPA ANOMALY FIELD AND EL NINO/ANTI-EL NINO EVENTS

In this paper, an analysis of the correlation between El Nino/anti-E1 Nion and the variation of stratosphere 50hPa height anomaly field has been made for the last 30 years. The results show that, in the winter (November to next January) before El Nino year, the negative height departure is found near the high latitude area, in the mid- latitude except Northern America, which has the positive height departure, and the vast area south of 30°N is controlled by negative height departure at 50hPa. But it is converse before anti-El Nino year. Moreover, the variation of 50hPa height anomaly field during the winter is greater than itself in other months and that for 500hPa. Thus, the variation of 50hPa height anomaly field in winter time is obviously indicative of the occurring of E1 Nino/anti-E1 Nino.