Changes in the dependence between global precipitation and temperature from observations and model simulations

摘要

Precipitation and temperature are physically related to each other with significant dependences that vary with seasons at regional and global scales. The dependence between precipitation and temperature (P-T dependence) plays a central role in characterizing the joint behaviour of the two variables. Along with extensive studies on the variation in the mean, variance, or extremes of precipitation and temperature under global warming, it is of particular interest to understand the climate-change impacts on the covariability of precipitation and temperature. The aim of this study therefore is to assess climate change impacts on the P-T dependence over global land areas from observations, and the performance of the current-generation Coupled Model Intercomparison Project (CMIP5) models in simulating these patterns. In general, the CMIP5 models correctly simulate the overall pattern of the P-T dependence (around 87-94% of global land areas). However, they capture both the sign and change of P-T dependence for relatively small regions (around 41-47% of global land areas). Results from this study may provide useful insights for the future development of climate models.