青藏高原OLR场的季节变化特征

该文利用1979～1991年卫星观测的OLR逐候资料，分析青藏高原OLR场的季节变化特征。结果表明:青藏高原OLR场具有显著的季节变化特点，在冬、夏两季高原OLR场表现为“缓变”态，在春、秋两过渡季节表现为“急变”态。同时发现，在春季高原西南部出现持续强的OLR候际正变化区，表明高原加热场在春季的持续加强。各年高原OLR场的季节变化有很大差异，在高原夏季来得早且季节过渡快的年份，相应印度地区的季风雨偏多；在高原夏季来得晚或正常时，印度地区的季风雨偏少或正常。

Characteristics of the Seasonal Variation in OLR Field over the Tibetan Plateau

By using 13-year pentad mean Outgoing Longwave Radiation (OLR) data (1979~1991) observed by NOAA satellites, the characteristics of the seasonal variation in OLR field over the Tibetan Plateau are investigated. The results show that the OLR field has outstanding seasonal variation. The major feature is that the OLR field is “ moderate variation condition” in winter and summer, and “abrupt variation condition” during the transition seasons of spring and autumn. There is persistent and strong positive interpentad change of OLR over the southwest of Tibetan Plateau in spring. It means that the enhanced heating field over the Plateau in spring has probably important effect on the seasonal transition of the regional climate. Additionally, the interannual variability of the seasonal transition of the OLR field over the Tibetan Plateau is also clear. It is closely related to the anomalies of the monsoon precipitation, that the summer over the Plateau comes early or late