The East Asian summer monsoon (EASM) and tropical cyclone (TC) landfall activity in the Western North Pacific (WNP) both influence East Asian summer rainfall (EASR), yet most studies investigate their impacts separately, neglecting their combined effect. This study addresses this gap by defining two rainfall types based on the concurrent occurrence of EASM and TC landfall along the coast of China: monsoon-TC landfall (MS-LTC) and monsoon-TC non-landfall (MS-NTC) rainfall. Using empirical orthogonal function analysis, we examine the interannual variability and underlying mechanisms of the two rainfall types during July–August from 1983 to 2023. MS-LTC rainfall features two positive anomaly centers over the WNP and North China, linked to a “meridional Pacific–Japan (PJ) pattern”, characterized by a low-latitude cyclone over the WNP and a mid-latitude anticyclone over the Sea of Japan. This structure is driven by North Atlantic tripole sea surface temperature anomalies (SSTAs), which excite downstream-propagating Rossby wave trains, enhance rainfall over the WNP, and transport moisture to North China. MS-NTC rainfall forms a belt extending from the WNP to the Korean Peninsula and southern Japan, associated with a “zonal PJ pattern”, featuring a cyclone over the WNP and an anticyclone over eastern Japan. This pattern is induced by Maritime Continent (MC) cooling, which suppresses convection and triggers a local Hadley circulation. The ascending branch of the Hadley circulation generates an anomalous cyclone over the WNP, acting as a Rossby wave source that propagates northeastward, ultimately giving rise to the zonal PJ pattern. Numerical experiments successfully reproduce the distinct circulation structures driven by the two key SSTAs and the vertical motions corresponding to the two rainfall types. This work deepens our understanding of EASR and highlights the structural diversity of the PJ pattern.

monsoon-TC landfall rainfall, East Asian summer monsoon, Western North Pacific tropical cyclone, Interannual variation, Pacific–Japan pattern