Multivariate bias corrections of global compound dry and hot events in CMIP6 model simulations

Climate extremes induced by global warming have remarkable impacts on water resources, agricultural production, and terrestrial ecosystems. Climatic model simulations provide useful information to analyze changes in extremes (e.g., droughts, heatwaves) under global warming for climate policies and mitigation measures. However, systematic biases exist in climate model simulations, which hinders accurate assessments of extremes changes. Bias correction methods have been employed to correct biases in climate variables (e.g., precipitation, temperature) in model simulations. Previous studies mostly focus on individual variables while the correction of inter-variable correlation (e.g., precipitation-temperature dependence) is still limited. Moreover, the concurrence of climate extremes (e.g., droughts and hot extremes), which is closely related to the dependence among contributing variables, may amplify the impacts. However, bias correction of the contributing variables of compound events is still limited but growing. In this study, we employ the multivariate bias correction (MBC) approach to correct the precipitation, temperature, and their dependence from CMIP6 simulations. We found that the MBC can improve the simulation of precipitation-temperature dependence and associated compound dry and hot events. This study can provide useful insights for improving model simulations of compound weather and climate extremes for impact studies and mitigation measures.