Variations in the Teleconnection of ENSO and Summer Rainfall in Northern China: A Role of the Indian Summer Monsoon*

Abstract

Observational studies have created a dilemma on how El Niño–Southern Oscillation (ENSO) may have affected interannual variations of summer rainfall in northern China; some suggested a consistent effect while others showed a complete lack of effect. This dilemma is resolved in this study, which shows that ENSO has affected the summer rainfall in northern China and the effect has varied at multidecadal scales. The question of how the ENSO teleconnection with northern China rainfall variation was established is addressed, and an answer pointing to the Indian summer monsoon as a “facilitator” connecting ENSO and northern China rainfall variation is examined. The Indian monsoon circulation interacted with the regional circulations in northern China in some epochs and such interaction was interrupted in other epochs. When the interaction was active, the Indian monsoon variations originating from ENSO, during El Niño or La Niña, was extended to affect the rainfall variation in northern China, creating a... Abstract Observational studies have created a dilemma on how El Niño–Southern Oscillation (ENSO) may have affected interannual variations of summer rainfall in northern China; some suggested a consistent effect while others showed a complete lack of effect. This dilemma is resolved in this study, which shows that ENSO has affected the summer rainfall in northern China and the effect has varied at multidecadal scales. The question of how the ENSO teleconnection with northern China rainfall variation was established is addressed, and an answer pointing to the Indian summer monsoon as a “facilitator” connecting ENSO and northern China rainfall variation is examined. The Indian monsoon circulation interacted with the regional circulations in northern China in some epochs and such interaction was interrupted in other epochs. When the interaction was active, the Indian monsoon variations originating from ENSO, during El Niño or La Niña, was extended to affect the rainfall variation in northern China, creating a...