Variability of winter extreme precipitation in Southeast China: contributions of SST anomalies

Abstract

Tropical SST anomalies are among the largest drivers of circulation regime changes on interannual time scales due to its characteristic heat capacity decay time scales. The circulation anomalies associated with extreme precipitation and the corresponding atmospheric response to SST anomalies are derived from ECMWF ERA-Interim reanalysis data by employing composite analysis and lagged maximum covariance analysis. Our results show that interannual variability of extreme winter precipitation in Southeast China is in close accordance with the interan- nual variability of total winter precipitation. Both are asso- ciated with similar abnormal circulation regimes, but for extreme precipitation events the circulation anomalies and moisture transport channels are significantly intensified. Two main moisture transport channels are captured: one extends from the North Indian Ocean through India and the Bay of Bengal to South China, and the other from the West Pacific Ocean through Maritime Continent and South China Sea towards South China, which are related to the preceding autumn SST patterns, El Nino and the Indian