Impact of ENSO regimes on developing- and decaying-phase precipitation during rainy season in China
- 1State Key Laboratory of Hydrology Water Resources and Hydraulic Engineering, Hohai University, Nanjing, 210098, China
- 2National Cooperative Innovation Center for Water Safety & Hydro-Science, Hohai University, Nanjing, 210098, China
- 3Department of Water Resources Engineering and Center for Middle Eastern Studies, Lund University, P.O. Box 118, Lund, 22100, Sweden
- 4Nanjing Hydraulic Research Institute, Nanjing, 210098, China
- 5Investigation Bureau of Hydrology and Water Resources, Ali, Tibet Autonomous Region, 859000, China
Abstract. This study investigated the influence of five El Niño–Southern Oscillation (ENSO) types on rainy-season precipitation in China: central Pacific warming (CPW), eastern Pacific cooling (EPC), eastern Pacific warming (EPW), conventional ENSO and ENSO Modoki. The multi-scale moving t test was applied to determine the onset and withdrawal of rainy season. Results showed that the precipitation anomaly can reach up to 30 % above average precipitation during decaying CPW and EPW phases. Developing EPW could cause decreasing precipitation 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 a larger effect on precipitation anomalies, 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.