The influence of El Niño on different types of persistent summer precipitation in the eastern China monsoon region

Based on daily precipitation collected at meteorological observation stations in mainland China from 1961 to 2018, impacts of different distribution types of El Niño events on persistent structure of summer precipitation over eastern China are explored, and reasons for the variation of persistent precipitation in different regions are analyzed. The north anomalous rain belt (North China, Inner Mongolia and southern part of Northeast China) corresponding to eastern Pacific (EP) El Niño events is formed mainly due to the synchronous increase of the frequency and intensity of short-persistent precipitation, and the contribution of short-persistent precipitation to the anomalous precipitation in the region exceeds 80%. The south anomalous rain belt (the Yangtze river basin) is formed mainly by the simultaneous increase of the frequency and proportion of cumulative precipitation days to total precipitation days of long-persistent precipitation. The most important reason for the formation of the abnormal rain belt (southern part of North China, southern part of Northeast China, Huanghuai and Jianghuai regions) corresponding to central Pacific (CP) El Niño events is the abnormal increase of short-persistent precipitation, which contributes about 60%, followed by long-persistent precipitation, which accounts for about 24%. The increase of short-persistent precipitation is characterized by the increases of frequency and intensity, while the increase of long-persistent precipitation mainly occurs to the south of the rain belt, which is the result of the simultaneous increase of frequency and the proportion of cumulative days. In two types of El Niño decaying summer, the variation of short-persistent precipitation in eastern China makes the greatest contribution to the abnormal variation of total precipitation, while the enhancement of long-persistent precipitation also plays an important role in the increase of total precipitation in the Yangtze river basin. The significant increases in the frequency of short-persistent and long-persistent precipitation are the main reasons for the formation of abnormal rain belts.