南京地区雾的气候特征

Climatological Characteristics of Fogs in Nanjing

利用1961—2006年南京气象站和江浦、六合、溧水、江宁、高淳5个南京郊区站地面资料,统计分析了南京地区雾天气的气候特征及其与气象要素的关系。结果表明:受地形和下垫面等特性的影响,南京地区各站雾日分布不均,有明显的地区差异。溧水、六合和南京比江浦、江宁和高淳更易出现雾天气,其中溧水雾日最多,年均为34.9 d。雾的季节分布表现为:秋冬季最多,春季次之,夏季最少。溧水、高淳、江浦年均雾日数表现出明显的上升趋势,而南京、江宁、六合雾日数略有下降。分析结果也指出,雾天气多出现在近地面弱风、高湿和弱高压等气象条件下。

Based on the meteorological observations at Nanjing Meterological Observatory and other five suburban meteorological stations （ Jiangpu, Luhe, Lishui, Jiangning and Gaochun） during 1961-2006, the climatological characteristics of fogs in Nanjing and their relationships with various meteorological parameters are analyzed. Results show that, depending on the topography and the nature of underlying surface, the occurrences of fog events at these six locations are different. The fog processes are more likely to happen at Lishui, Luhe and Nanjing than at other three places （Jiangpu, Jiangning and Gaochun） with the highest frequency of fogs（34.9 days annually） at Lishui. Fog events at six stations show the same seasonal characteristics with the maximum frequency in winter and autumn, the next in spring and the minimum in summer. It is also found that the annual fog days at Lishui, Gaochun and Jiangpu are increasing and an opposite tendency occures at Nanjing, Jiangning and Luhe. Results reveal that the fog events are more likely to occur under the conditions of weak surface wind, high humidity and weak high system.