Simulation of extreme precipitation changes in Central Asia using CMIP6 under different climate scenarios.

Central Asia has a dry climate, scarce water resources, extremely fragile ecosystems, and frequent extreme precipitation events. Using the data of 22 global climate models in the CMIP6 plan, the trend of the extreme precipitation index under four Shared Socioeconomic Pathways (SSPs) was estimated by calculating eight extreme precipitation indices in Central Asia and optimizing the best multi-model set using the Taylor evaluation and comprehensive score. The results showed that in Central Asia, the CMIP6 mode and multi-mode collection can reasonably reproduce the regional differences of various severe precipitation indices. However, these results only performed well for consecutive dry days (CDD) and annual total precipitation (PRCPTOT), but poorly for the replication of extreme high- and low-value regions. We found that the simulation effect of the multi-mode ensemble results was better than that of a single mode, and that CMIP6 can roughly depict the evolving characteristics of extreme precipitation events. However, the CMIP6 data performed poorly in terms of spatial divergence ability characteristics. According to the estimated results, mountainous regions have experienced considerable changes, and a significant increase in the range of change was observed for severe precipitation (consecutive wet days (CWD), single day maximum precipitation (Rx1day), and PRCPTOT) in wet and dry regions during the twenty-first century. Simultaneously, the humidification trend accelerated after 2050, and four shared socioeconomic paths showed similar trends; however, the extreme precipitation rate was higher under the high forcing path. Consecutive dry days (CDD) in Central Asia decreased by 90% under SSP5-8.5 relative to SSP1-2.6, whereas CWD, Rx1day, and PRCPTOT increased by 20%, 150%, and 118%, respectively. [ABSTRACT FROM AUTHOR]