Impact of the central-Pacific ENSO on the Tibetan Plateau precipitation in boreal spring

Abstract

The importance of spring Tibetan Plateau (TP) precipitation is increasingly recognized. This study investigated the primary spatiotemporal features of spring Tibetan Plateau (TP) precipitation and revealed its pronounced impacts from El Niño–Southern Oscillation (ENSO). The spring TP precipitation anomalies are majorly featured by a west–east spatial pattern with interannual variations correlated with the spring central-Pacific (CP) ENSO. This west–east precipitation pattern leads to more precipitation in the western TP and less in the eastern TP under the spring CP El Niño, which is reversed under the spring CP La Niña. The ENSO-related Walker circulation variations and induced Indian Ocean warming that further excite anomalous zonal–vertical and meridional–vertical circulations south of TP are crucial to the spring TP precipitation through configuring the opposite anomalies of vertical motions and moisture convergence over western to eastern TP. The CP ENSO could be a potential precursor to the spring TP precipitation owing to its relatively long predictability and a summer persistence barrier.