Climate change projections in Central Asia based on the CORDEX-CA-II high-resolution simulations

This study provides potential climate projections for Central Asia (CA) based on multi-regional climate model (RCM) outputs from the Coordinated Regional Climate Downscaling Experiment for Central Asia (CORDEX-CA-II). Despite some systematic biases, all RCMs effectively capture the main features of observed temperature and precipitation means and extremes over CA, with notable variations in model performance due to differences in the driving global climate models and the RCMs themselves. Overall, REMO consistently outperforms ALARO in simulating temperature-related indices, and ALARO-0 provides more accurate simulations for precipitation-related indices, and the multimodel ensemble (MME) tends to outperform individual RCMs. Under the representative concentration pathway (RCP) scenarios of RCP2.6 and RCP8.5, the MME results indicate a clear warming trend across CA for all temperature-related indices, except for the diurnal temperature range, with annual temperatures projected to increase by 0.15°C (10 yr) −1 and 0.53°C (10 yr) −1 , respectively. Both scenarios exhibit similar spatial distributions in projected annual precipitation, characterized by peak increases of ∼0.2 mm d −1 in northern CA. The number of consecutive dry days is projected to slightly increase under RCP8.5, while it is expected to slightly decrease under RCP2.6. This study improves our understanding of the applicability of RCMs in CA and provides reliable projections of future climate change. 本文基于CORDEX-CA-II中的多区域气候模式 (RCMs) 对中亚未来气候变化进行预估分析.结果表明, 所有RCM均能再现温度和降水的主要气候态分布及极端事件, 其中REMO在温度相关指标模拟方面表现更好, 而Alaro-0在降水相关指标方面更具优势, 且多模式集合平均 (MME) 结果优于单个RCM.在RCP2.6和RCP8.5排放情景下, 除日较差外, 中亚地区的温度相关指标均呈现出一致的上升趋势, 而年均降水变化的空间分布也较为相似, 高纬度地区增幅最为显著.此外, 在RCP8.5情景下, 连续干燥日数预计将略有增加, 而在RCP2.6情景下则略有减少.