Anthropogenic influence has intensified the severity of summer compound hot and drought events over xinjiang, China

Abstract

Compared with individual hot or drought extremes, compound hot and drought events (CHDEs) usually cause more disastrous socio-economic damage. Thus, understanding the change of CHDEs in the context of global warming is crucial for effective adaptation and mitigation strategies. This article, based on the CN05.1 gridded dataset and 33 Coupled Model Intercomparison Project Phase 6 (CMIP6) model simulations, examines the change in summer (June–July–August) CHDEs over Xinjiang, China from 1961 to 2020 and assesses the contribution of human influence using the optimal fingerprint method. The observational results show a significant upward trend in the severity of CHDEs over Xinjiang, among which the change in moderate CHDEs shows a dominant contribution. The CMIP6 multi-model ensemble mean simulation with all forcing generally matches the observation in the change of CHDEs over Xinjiang. Moreover, anthropogenic and natural forcings can be detected and separated from each other, with human activities contributing most to the CHDE change. Furthermore, the three-signal analysis of model responses to greenhouse gas, anthropogenic aerosol, and natural forcings indicates that the greenhouse gas forcing is primary to the increased severity of CHDEs in Xinjiang, while the influence of anthropogenic aerosol forcing cannot be detected.