全球变暖背景下南宁地区寒潮活动的变化

 利用1961-2005年南宁地区8个气象观测站的逐日平均气温和最低气温资料，分析近45 a南宁地区寒潮活动的特征及其多年变化特点，并且研究了环流场异常对寒潮事件发生频率的影响。结果表明，南宁地区寒潮活动期区域差异较大：东部开始早，结束晚；西北部开始晚，结束早，寒潮出现在12、1和2月。近45 a来，寒潮具有两次跃变异常，分别发生在20世纪70年代前期和90年代后期；寒潮活动总的趋势是减少的，减少频数为0.12次/10 a，这主要与日最低气温比较高有关。此外，针对强寒潮活动年和弱寒潮活动年，给出了500 hPa典型高度距平场特征。

Change of Cold Wave in the Nanning Area Under Global Warming

Using the daily mean/minimum air temperatures data at 8 weather stations in the Nanning area during 1961-2005, we analyzed the change characteristics of cold wave activity in the Nanning area in recent 45 years and the impact of anomalous circulations on the frequency of the cold wave events affecting Nanning. The results show that the cold wave activity period is different in various areas of the Nanning area, that is, the cold wave activity begins early but ends late in the east, while it begins late but ends early in the northwest. The cold waves occur mainly in December, January and February. Over the past 45 years, cold waves had two abnormal changes in the early 1970s and late 1990s. The general trend of cold wave activity is decreasing at a rate of 0.12 time/10 a. This phenomenon is mainly related to the obvious rise in daily minimum temperature. The typical circulation characteristics for strong/weak cold wave activity years are illustrated with respective composite 500 hPa height anomaly fields.