【摘要】 通过对多年地面气压和500hPa高度等资料的统计分析,本文发现在埃尔尼诺现象发生的前一年10—12月和当年1—3月,东亚和西太平洋地区的大气环流都有明显异常,主要特征是东亚有频繁强冷空气活动,且环流异常有由高纬向低纬地区推移的现象.冬季东亚频繁的强冷空气活动使西太平洋副热带高压位置逐渐偏南,造成中、西太平洋信风减弱,可能是埃尔尼诺发生的原因之一。 埃尔尼诺年夏季,由于遥相关机制,东亚及西太平洋中纬地区出现地面气压和高度场的负距平,西太平洋副高位置持续偏南. 基于统计分析结果,本文绘出了一个东亚及西太平洋大气环流与埃尔尼诺相互影响的模型。更多还原

【Abstract】 Through the statistical analysis in surface pressure, 500 hPa height and others, it is noticed in this paper that the general circulation in the East-Asia and the West-Pacific has had obvious abnormality in October-December and January-March before El Nino happened. During those months, there are frequent cold wave in the East-Asia and the abnormality of general circulation seems to be movable from higher latitude to lower latitude. The frequent stron-ger cold waves in the East-Asia in winter cause the location of the West-Pacific subtropical high to be on the south side gradually. Then the trade wind over the middle and the West-Pacific is weakened. This may be one of the reasons that cause El Nino.In the summer of El Nino year, owing to teleconnection, there is a negative anomaly of surface pressure and 500 hPa height in the East-Asia and the West-Pacific. The west-Pacific subtropical high is to the south continuously and weaker.Based on the statistical analysis, a scheme on the interaction between the atmospheric circulation over the East-Asia and the West-Pacific and El Nino is given in this paper.更多还原