中文摘要：

利用NCEP／NCAR资料研究了2008年1月中下旬四川盆地的极端低温雨雪灾害。结果表明：四川盆地的低温雨雪天气与南来的水汽变化及长江流域的锋生作用有密切关系，在对流层中低层700hPa上，四川盆地长时间存在稳定的水汽辐合区，水汽辐合的时段基本与盆地冷空气活动时间段一致，这为低温降水的发生提供了水汽条件。另一方面，长江流域长时间存在一个“东西带状”分布的锋生带，这个锋生带的稳定使南来的西南水汽在四川盆地及长江流域以南地区受阻，从而形成了水汽长时间封闭，并引起了中低层的对流不稳定。因此，低层“东西向带状”锋生的长期维持使南来水汽受封闭是产生此次灾害的重要物理机制之一。

英文摘要：

Using NCEP / NCAR data to analyze the extreme cold rain and snow disaster of Sichuan Basin in January 11 - 25th 2008. The results showed that extremely cold rain and snow weather of Sichuan Basin was related well to the variations of water vapor , frontogenetic function of Yangtze River Basin. at the mid - lower level of the troposphere, especially at 700 hPa level, there was water vapor convergence exiting lastly in Sichuan Basin for long time. And the time of convergence of water vapor was congruous with activities of cold air in Sichuan basin, and provided the water vapor conditions for the occurrence of low - temperature disaster. On the other hand, there was frontogenetic function of east - west band distribution in Yangtze River basin. Southwest water vapor, hindered by the stability of the frontogenetic, lasted in Sichuan basin and the area south of the Yangtze River Basin , as a result , water vapor mass was closed for long time in Yangtze River Basin, and aroused troposphere instability at the lower level. Therefore, maintenance of the frontogenetic east - west banding lasted for long time at lower level and water vapor was closed by it , this was an important physics mechanism for producing the cold rain and snow disaster.