Influences of the Pacific Decadal Oscillation on the East Asian Summer Monsoon in non-ENSO years

Abstract

The impact of different phases of the Pacific Decadal Oscillation (PDO) on East Asia summer monsoon and related precipitation in non-ENSO (El Niño-Southern Oscillation) years is examined in this article. Associated with the large-scale sea surface temperature and circulation change, anomalous summer (JJA mean) precipitation in East China shows tripolar pattern, with increased (decreased) precipitation in the Yangtze-River Valley (North and South China) in positive PDO phase without ENSO. Besides, the western Pacific subtropical high exhibits expansion and westward shift in positive PDO phase along with significantly different sub-seasonal variation.