Although moisture is an important factor affecting precipitation in arid Central Asia (ACA), the water vapour sources and their influencing factors are unclear. This study investigates the moisture sources of extreme precipitation events in summer over Northern ACA and in winter over Southern ACA. The results show that in summer over Northern ACA, the water vapour at low and upper atmospheric levels is mainly transported from the North Atlantic and the Arctic Ocean. In addition, the water vapour in winter over Southern ACA is mainly transported from the North Atlantic and the Northern Indian Ocean. Among these sources, anomalous moisture from the North Atlantic is transported to Northern and Southern ACA along the Mediterranean pressure ridge and the Aral Sea pressure trough. In addition, anomalous moisture in Northern ACA from the Arctic Ocean is closely associated with the negative height anomaly near ACA and with the positive height anomaly in the Mediterranean extending northward to the Arctic Ocean; this results in the high‐latitude moisture transporting along the western edge of the cyclone in Northern ACA. In Southern ACA, low‐latitude water vapour from the Northern Indian Ocean is affected by negative and positive height anomalies in Northwest and Southeast ACA. In addition, significant ascending motion occurs in the study area which provides the necessary dynamic conditions for precipitation. The precipitation variations in Northern and Southern ACA are also related to sea‐surface temperature variations, mainly in the North Atlantic, Arctic Ocean, Mediterranean Sea, and Northern Indian Ocean. Therefore, moisture from the North Atlantic, Arctic Ocean, and the Indian Ocean converge and together influence precipitation development during summer over Northern ACA and in winter over Southern ACA.

中文翻译：

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中亚干旱地区极端降水事件的水源及其与大气环流的关系

尽管水分是影响中亚干旱地区（ACA）降水的重要因素，但水汽源及其影响因素尚不清楚。这项研究调查了北部ACA夏季和南部ACA冬季极端降水事件的水分来源。结果表明，在夏季，北ACA地区的大气水汽主要来自北大西洋和北冰洋。此外，南部ACA冬季的水汽主要从北大西洋和北印度洋输送。在这些来源中，北大西洋的异常水分沿着地中海的压力脊和咸海的压力槽被输送到北部和南部的ACA。此外，北冰洋北冰洋异常水位与北冰洋附近的负高度异常密切相关，与地中海向北延伸到北冰洋的正高度异常密切相关。这导致高空水汽沿ACA北部的气旋西缘输送。在南部ACA，来自北印度洋的低纬度水汽受到西北和东南ACA高度正负的影响。此外，研究区域发生了明显的上升运动，这为降水提供了必要的动态条件。北部和南部ACA的降水变化也与海表温度变化有关，主要在北大西洋，北冰洋，地中海和北印度洋。因此，