Changes in concurrent hot and dry extremes based on convection-permitting projections under the SSP5-8.5 scenario

Accelerated global warming is anticipated to intensify the frequency and severity of concurrent extremes, leading to negative impacts that surpass those of individual extreme events. Southeastern China has experienced a rise in the occurrence of concurrent hot and dry extremes in recent years, and the expected amplification of such events is likely to worsen economic losses and endanger human well-being. Due to the significant impacts of such concurrent extremes, there is a strong demand for dependable future projections at the local level. However, most studies have focused on univariate analysis of single extremes using coarse-grid global climate models (GCM), which may not fully capture the region-specific climate impacts of global warming. To address this issue, this study will utilize convection-permitting (CP) regional climate modeling and multivariate statistical analysis to evaluate the future changes in concurrent hot and dry extremes. The Weather Research and Forecasting model (WRF) will be used to downscale the bias-corrected CMIP6 GCM projections under the SSP5-8.5 scenario at the convection-permitting scales (4km) over southeastern China. The study aims to investigate the process-based added value of CP projections when assessing future changes in concurrent hot and dry extremes over densely populated regions in China. The high-resolution simulation is expected to enhance the understanding of compound climate extremes and provide quantified insights into prospective climate risks.

[Acknowledgements]

This research was supported by project GRF16308722, which was funded by the Research Grants Council (RGC) of Hong Kong. This research was also partly supported by Korea Environmental Industry & Technology Institute (KEITI) through Water Management Program for Drought Project, funded by Korea Ministry of Environment (MOE) (2022003610003)