广东省雾霾天气能见度的时空特征分析Ⅰ:季节变化

Spatial-temporal characteristic of meteorological visibility under fog and haze condition in Guangdong province

雾霾已经成为一种新的气象及环境灾害性现象,分析雾霾天气下低能见度的时空分布特征,对掌握雾霾的发生规律和减灾预报具有重要意义。文章利用1980—2003年广东省沿海地区26个地面气象观测站23年的气象观测资料,分析了广东省雾霾天气下能见度的时空分布特征。分析结果发现,1980—2003年广东地区雾霾天气下能见度的季节变化规律与雾天气时能见度的季节变化规律大体一致,即广东地区低能见度天气主要受雾天气的影响;另一方面,雾、霾天气时能见度的季节变化规律有很大不同,雾天气时能见度观测值在冬、春两季相对较高,最低值出现在3月份,最高值出现在9月份,其年变化表现为峰—谷型、稳定型和不规则波动型三种变化;霾天气时能见度的值在秋、冬两季相对较高,最低值出现在6月份,而且在5、6、7三个月中能见度值都很低;受广东沿海地形特征影响,雾天能见度的空间分布从西到东呈低—高—低—高的波列状分布,而霾天气时能见度的空间分布则没有明显的区域差异。

Fog and haze are now becoming new disaster phenomena in meteorological and environmental fields. So far the spatial and temporal distribution of fog and haze phenomena are not quite clearly understood and studied due to lacking of thorough research, which is the fundamental for further research. In this article 23 years （from 1980 to 2003） observed visibility and other meteorological data of 26 stations in Guangdong province were investigated and the temporal and spatial distribution of visibility during fog and haze occurrence were studied. It＇s found that seasonal variability during fog occurrence is consistent with that under fog-haze occurrence, which means fog account mainly for low visibility in Guangdong province. While the seasonal cycle of mean visibility averaged on all stations appears quite different under fog and haze conditions respectively. During fog occurrence, visibility arc relative high in summer and autumn （maximum in September） and low in winter and spring （minimum in March）. All the 25 station exhibit 3 kinds of seasonal cycle, namely ascrest-trough type, steady type and irregular wave type. During haze occurrence, visibility is relatively high in autumn and winter and low in spring and summer, especially in May, June and July （minimum in June）. Besides, the spatial distribution of visibility during fog occurrence is closely related to the terrain variation of Guangdong Province, which exhibit row-shape low-high-low-high variation from west to east. However, the spatial distribution of visibility during haze occurrence exhibits no obvious spatial diversity.