厄尔尼诺年和反厄尔尼诺年北半球500hPa非绝热热流量场的特征

FEATURES OF 500hPa DIABATIC HEATING OVER THE NORTHERN HEMISPHERE DURING EL NINO AND ANTI-EL NINO YEARS

摘要:

本文应用谱方法,诊断、计算了1964—1985年间,6个厄尔尼诺年和6个反厄尔尼诺年北半球月、季大气非绝热热流量距平场。结果表明:厄尔尼诺现象对大气非绝热热流量距平场具有显著影响,大气的响应表现为低纬和中高纬非绝热热流量正负距平中心有组织的优势排列,其位相或强度存在低频振荡,并且差值中心表现为双月周期。反厄尔尼诺年,大气具有分布不变,但距平中心基本上为反位相的响应形式。最后,通过海气相关分析,指出了海温异常是决定大气非绝热热流量异常的最重要的原因。

Abstract:

The monthly and seasonal diabatic heating anomaly fields in the atmosphere over the Northern Hemisphere during 6 E1 Nino and 6 anti-E1 Nino years (1967-1985) are calculated by using spectral representation. Results suggest that E1 Nino events have a significant influence upon the diabatic heating anomalies in the atmosphere. The atmosphere response is characterized by the well-organized positive and negative centers of diabatic heating in the lower and mid-high latitudes, with their phase and intensity having features of low frequency oscillation and difference centers showing quasi-bimonthly fluctuations. During anti-E1 Nino years the atmospheric distributions are the same as during E1 Nino years except for the anti-phase of the anomaly center values.As shown from the analysis of correlationship between sea surface temperature (SST) and atmospheric variables, the anomaly of SST is the dominant reason for the diabatic heating anomaly in the atmosphere.