一次罕见强冷空气过程气候背景分析

The Analysis of Climatic Background from One Strong Cold Air Process

利用micaps常规气象观测资料、NCEP／NCAK再分析资料以及北极涛动指数等，分析了大气环流形势和气候背景对2009年11月11～16日广东省强冷空气过程的影响。结果表明：此次天气过程是在一次中等强度的“厄尔尼诺”事件背景下发生的，与北极涛动的负异常造成的异常环流形势有关。在”北脊南槽”和西太平洋副热带高压偏北偏强的形势下，北方冷空气沿西伯利亚南下．同时采自南海和青藏高原以南低纬度地区的水汽源源不断地输送，使得冷暖气流在广东交汇，造成了强降温和降雨过程.

By using observation data, the NCEP/NCAR reanalysis data and AO indices, the analysis of the atmospheric circulation and climatic background of strong cold air process on 11 to 16 November 2009. The main results are：（1）the strong cold event occurred under Medium-strength El Nino, it is related to positive AO anomalies;（2）the strong cold front met the warm front in the sky in Guangdong when the continuous moisture and strong ascending stream provided from South China Sea and Tibetan Plateau low latitude area ,then caused the heavy rain and obvious fall of temperature.