Strengthening influence of El Niño on the following spring precipitation over the Indo-China Peninsula

Abstract

AbstractEl Niño is a dominant source of interannual climate variability around the world. Based on the observed and reanalyzed datasets for the period of 1958-2019, this study explores the influence of El Niño on the spring precipitation over the Indo-China Peninsula (ICP). The results show that El Niño has a significant negative correlation with the following spring precipitation over the ICP. However, this climatic teleconnection of El Niño was unstable, with an obvious interdecadal strengthening since the early 1990s. During the decaying spring, the El Niño-related sea surface temperature (SST) anomalies would induce an abnormal downward motion along with an anomalous low-level anticyclone over the western North Pacific. Before the early 1990s, such El Niño-induced atmospheric circulation anomalies were located to the east of the ICP, exerting little influence on the spring ICP precipitation. In contrast, since the early 1990s, the abnormal downward motion and anomalous low-level anticyclone extended westwards covering the whole ICP, hampering local spring precipitation. This interdecadal change is owing to a relatively stronger intensity and longer duration of the El Niño-related warm SST anomalies over the tropical central Pacific in the epoch after the early 1990s (1992-2019) than in the previous decades (1958-1991). Our findings highlight a strengthening effect of El Niño on the following spring climate over the ICP since the early 1990s, which has great implications for the regional climate prediction.