Changes of summer precipitation in China: The dominance of frequency and intensity and linkage with changes in moisture and air temperature

Abstract

Abstract Using observed precipitation and the National Centers for Environmental Prediction–National Center for Atmospheric Research reanalysis, the changes in the metrics of the summer precipitation in China, the dominance of frequency and intensity of daily extreme precipitation, and the linkage with changes in moisture and air temperature are explored. Results show that over the recent 50 years, the total summer rainfall increased over the southeast and the west and decreased over the northeast. The changes in the frequency, identified with the 95% threshold and Poisson regression, and rainfall extremes show similar spatial patterns. The relative importance of the changes in frequency and intensity in the variability and changes in extreme precipitation are estimated. It is shown that, while the interannual variability of the rainfall amount is dominated by the frequency change in almost all stations, the long‐term change of rainfall amount can be dominated by both frequency and intensity, depending on the station. The change in the rainfall total is linked to changes in atmospheric moisture and temperature. The results show that the variability and change of the rainfall total can be dominated by changes in both moisture and air temperature, and the relative importance depends on the region.