This study revisits the impacts of different types of El Niño on East Asian summer precipitation (EASP) with observed and re-analyzed data from 1958 to 2015. It focuses on the boreal summer preceding peaks of El Niño when prominent SST anomalies are mainly situated in the tropical Pacific. Distinct responses of EASP are obtained for the three identified types of SST anomalies noted as summer EP (Eastern Pacific) El Niño, summer MP (Mixed-type Pacific) El Niño, and summer CP (Central Pacific) El Niño. In the case of summer EP El Niño, there is a robust south-north rainfall dipole with anomalous dry conditions in North China and wet conditions in Southeast China. Such a rainfall pattern is mainly attributed to a low-pressure anomaly over Northeast Asia. For summer MP El Niño, it presents a tripolar pattern of precipitation anomalies with wetness along the Yangtze-Huaihe River valley and dryness in both South and North China. This is due to the presence of low-pressure anomalies over Northeast China and a westward shift of the Western Pacific Subtropical High. Summer CP El Niño shows a triangle-pattern of precipitation anomalies with wet conditions in both southern and northern China, but dry conditions in the Jianghuai region (north of the Yangtze River in East China), caused by low-pressure anomalies over central-north China.

Further study investigates how different types of summer El Niño induce different changes of the Walker circulation and associated large-scale convergence/divergence outside the tropics, and ultimately provoke different responses of atmospheric circulation. For summer EP El Niño, tropical perturbations over the east-central tropical Pacific and over North India can enter into the subtropical jet and make a mid-latitude low pressure belt response at upper levels of the atmosphere. For summer MP El Niño, the perturbation over the east-central tropical Pacific seems ineffective in transmitting atmospheric anomalies to mid-latitudes. As a result, they are mainly confined to the tropics and lead to a general rise of the upper-level geopotential height over the entire tropics. However, the perturbation over Northwest Africa can excite northeastward propagating Rossby waves in mid-high latitudes. For summer CP El Niño, the induced fluctuant wave train within the subtropical jet is likely the competing effect of perturbations over the east-central tropical Pacific, North India and North Africa. Furthermore, for all the three types of summer El Niño, perturbations can trigger a similar low-level meridional wave train along the East Asian coast through the monsoon trough. However, a slight westward shift of the wave train makes a sensitive impact on EASP.