南疆西部暴雨过程水汽来源及输送特征

Characteristics of water vapor source and transport during rainstorm in western southern Xinjiang

利用HYSPLIT模式和GDAS资料,对南疆西部1981-2020年暖季(4-9月)16例暴雨(平原、山区)后向水汽轨迹追踪、主要通道及不同源地的水汽贡献进行了分析。结果表明:水汽主要源自西南亚、中亚、地中海和黑海及其附近、大西洋及其沿岸;平原区850 hPa还有源自南疆和北疆的水汽。500 hPa水汽主要从偏西通道输入暴雨区;源自西南亚和中亚的水汽对暴雨的贡献较大,损失也较大。对流层低层水汽主要从偏西和偏东2个通道输入暴雨区;700 hPa各通道及各水汽源地对暴雨的贡献,不同区域存在差异;平原区暴雨850 hPa偏东通道对暴雨的贡献最大,各源地水汽沿途损失较小,北疆源地对暴雨的贡献最大。平原区源自西南亚、中亚、南疆和北疆的水汽主要输送至700 hPa及以下,源自地中海和黑海附近、大西洋及其沿岸的水汽主要输送至700 hPa以上的高度;500 hPa上,平原区暴雨从>2 000 m的高度输送的水汽占主导地位,山区则相反。在南疆西部暴雨中存在南疆和北疆的水汽源,在特定条件下,有北美洲、北非的水汽源,与以往的研究成果不同。

Using HYSPLIT and GDAS, it will be analyzed what is the water vapor contribution of the 16 rainstorms, and what includes backward water vapor trajectory tracking, main channels and different sources in the warm season of 1981-2020 in western southern Xinjiang(April-September). the result shows: Water vapor mainly originates from Southwest Asia, Central Asia, the Mediterranean Sea and the Black Sea and their vicinity, the Atlantic Ocean and its coasts, at 850 hPa in the plain area, there is water vapor originating from southern and northern Xinjiang. At 500 hPa, water vapor mainly enters the rainstorm area from the west channel, the contribution of water vapor to the heavy rain is greater and the loss is also greater, that comes from Southwest Asia and Central Asia. In the lower troposphere, there are two main channels for water vapor to enter the rainstorm area from the west and east. At 700 hPa, the contribution of each channel and each water vapor source to the rainstorm is different in different regions. In the plain area of 850 hPa, the eastward channel of the heavy rain contributed the most to the heavy rain, and the water vapor loss along the source area was small, and the largest contribution to the heavy rain was in the source area of northern Xinjiang. In the plain area, water vapor originates from Southwest Asia, Central Asia, Southern Xinjiang and Northern Xinjiang. It is mainly transported to 700 hPa and below. It originates from the water vapor near the Mediterranean Sea and the Black Sea, the Atlantic Ocean and its coast, it is mainly transported to a height above 700 hPa. At 500 hPa in the plain area, the water vapor transport of heavy rain is dominant from more than 2000 m, while the mountainous area is the opposite. In the western part of southern Xinjiang, there are sources of water vapor from southern and northern Xinjiang during heavy rains, and under certain conditions, there are sources of water vapor from North America and North Africa, which are different from previous research results.