Non-uniform changes of daily precipitation in China: Observations and simulations

Daily precipitation of different intensities is expected to change differently in response to global warming. Based on station observations and simulations from the latest climate models, we investigated the non-uniform features of changes in daily precipitation frequency, intensity and amount over China. Results show that western China experiences an overall wetting trend across the spectrum of precipitation intensity, while eastern China exhibits negative trends in light-to-moderate precipitation and positive trends in heavy-to-extreme precipitation with respect to precipitation frequency and amount. Changes in precipitation intensity do not show a spatially consistent pattern of intensification in most intensity spectra, but exhibit the most pronounced intensification in heavy-to-extreme precipitation. Interestingly, changes in precipitation frequency dominate changes in the amount of precipitation for each intensity level, particularly for the spatial patterns. Although climate models show limited skills in reproducing the magnitudes of these observed changes, they show skills in simulating the sign of the changes. Also, they reasonably reproduce the observed non-uniform patterns of daily precipitation changes, especially for changes in the contributions from different intensity levels to annual total precipitation on average over the whole country. The evaluation of current climate models in simulating daily precipitation changes as a function of precipitation intensity suggests that improvement in the detection and attribution of precipitation changes in China can be gained by dividing daily precipitation into different categories.