Influences of the Atlantic Ocean on the summer precipitation of the southeastern Tibetan Plateau

Abstract

The southeastern Tibetan Plateau is one of the predominant summer rainfall regions in the world and is also the crucial water vapor channel of the Asian summer monsoon. The rainfall variability in the region influences not only the local communities but also downstream communities in East Asia. However, previous studies have exhibited large rainfall biases in this region in state-of-the-art climate models. Understanding the observed rainfall variability provides an opportunity to identify the origin of model biases and to lay a foundation for improving model performance. In this study, the interannual variability of the summer precipitation (May-September) over the southeastern Tibetan Plateau was investigated based on National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis monthly mean data from 1979 to 2010. The associated atmospheric circulation anomalies of the southeastern Tibetan Plateau summer precipitation (SET-PR) display a North Atlantic Ocean-Europe-Asia teleconnection pattern, indicating a possible role of the Atlantic climate in the SET-PR. Further studies have revealed that the Atlantic sea surface temperature (SST) anomalies have the greatest influence on the SET-PR via the Rossby wave response, whereas the SST anomalies in the Indo-Pacific have less of an influence on the SET-PR because their main impacts are confined to the western North Pacific subtropical high and the monsoonal circulation there. This paper also documents the detailed spatial pattern of the atmospheric circulation anomalies associated with the SET-PR and Atlantic SST year-to-year variability. © 2013. American Geophysical Union. All Rights Reserved.