The impact of global warming on Central Asian precipitation suffers from huge uncertainties, yet their origins remain largely unidentified. This study investigates the inter-model spread in the projection of winter Central Asian precipitation (WCAP) using models from the Coupled Model Inter-comparison Project Phase 6. The results reveal a homogenous wetting trend in WCAP, with the primary source of uncertainty in its magnitude stemming from the dynamic component of vertical moisture advection. This dynamical uncertainty is further attributed to an out-of-phase variation between two Eurasian westerly jets, which can enhance the upward motion over Central Asia through positive relative vorticity advection and warm temperature advection. The opposing variation between two westerly jets can be traced to cooling in the North Pacific, which alters jet intensity through changes in the meridional temperature gradient. This study informs policy and adaptation strategies to better cope with future climate shifts in Central Asia.

中文翻译：

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全球变暖下中亚降水变化预估的模式间不确定性


全球变暖对中亚降水的影响存在巨大的不确定性，但其起源在很大程度上仍未确定。本研究使用耦合模式相互比较项目第 6 阶段的模式调查了冬季中亚降水 （WCAP） 预估中的模式间传播。结果揭示了 WCAP 的均匀润湿趋势，其大小的主要不确定性来源来自垂直水分平流的动力学分量。这种动力学的不确定性进一步归因于两个欧亚西风急流之间的异相变化，这可以通过正相对涡度平流和暖温平流增强中亚上空的上升运动。两个西风急流之间的相反变化可以追溯到北太平洋的冷却，它通过经向温度梯度的变化来改变急流强度。本研究为政策和适应策略提供信息，以更好地应对中亚未来的气候变化。