Impact of ENSO regimes on developing and decaying phase precipitation during rainy season in China

Abstract. This study investigated the influence of five El Niño‐Southern Oscillation (ENSO) types (i.e., Central Pacific Warming (CPW), Eastern Pacific Cooling (EPC), Eastern Pacific Warming (EPW), conventional ENSO, and ENSO Modoki) on rainy-season precipitation in China. The multi-scale moving t-test was applied to determine the onset and withdrawal of rainy season. Results showed that there is a higher probability for flooding during decaying CPW and EPW phases in most parts of China with a largest precipitation anomaly reaching 30 % above average precipitation. Developing EPW could trigger droughts over large areas in China with 10–30 % lower than average precipitation in most areas. Conventional El Niño in the developing phase had the largest influence on ENSO-related precipitation among developing ENSO and ENSO Modoki regimes. Decaying ENSO also showed larger effect on the occurrence of drought and flood, compared to decaying ENSO Modoki. The difference between rainy-season precipitation under various ENSO regimes may be attributed to the combined influence of anti-cyclone in the western North Pacific and the Indian monsoon. Stronger monsoon and anti-cyclone are associated with enhanced rainy-season precipitation. The results suggest a certain predictability of rainy-season precipitation related to ENSO regimes.