青藏高原及其附近地区大气周期振荡在OLR资料上的反映

THE ATMOSPHERIC OSCILLATIONS OVER THE TIBETAN PLATEAU AND SURROUNDING AREAS AS REVEALED FROM OLR DATA

本文根据最近8年卫星所接收到的地球向外长波辐射(OLR)资料,分析青藏高原及其附近地区的周期振荡特征。结果表明:除了季节变化之外,准8d振荡和30—50d低频振荡是两个很显著的周期活动,前者和高原低涡活动有关,而后者则与夏季进入高原的两条水汽通道相联系。统计说明,高原地区主要受南来系统的影响,特别在夏半年。 本文的结果表明,对于常规资料稀少的高原地区,OLR是一种很有用的资料,与其它资料结合,将有助于揭露天气事实和研究天气过程的演变。

Some of the characteristic features of the atmospheric oscillations over the Tibetan Plateau and surrounding areas were investigated by using OLR data during the eight years. The basic periods were the quasi 8-day and 30-50 days, except the seasonal cycle. The quasi 8-day oscillations were related to the activities of the Plateau vortex. The low-frequency (30-50 days) OLR modes were closely tied to two moisture channels which reached the Tibetan Plateau from the Bay of Bengal and the northwest of India during the rainy season.The results of this paper indicated OLR data were useful for the investigation of the Plateau