1980—2012年汕头市灰霾天气的气候特征

Climatological Characteristics of the Hazy Weather in Shantou City in 1980-2012

利用汕头市国家基准气候站1980—2012年的气象观测资料,对汕头市灰霾天气气候特征进行分析,找出灰霾天气出现时的主要气象影响因素。结果表明:近33年来,汕头市灰霾日数总体呈现上升趋势;灰霾天气具有明显的季节差异,呈现冬季>春季>秋季>夏季的季节特征;出现灰霾天气主要以轻微灰霾为主,轻度灰霾次之,没有出现重度灰霾;汕头市共出现176次灰霾天气过程,从20世纪90年代开始连续3 d或以上的灰霾天气过程明显增多,而连续灰霾过程大多持续3~5 d;偏东风向比较容易出现灰霾天气,在较小风速和较高相对湿度的条件下有利于灰霾天气的形成和维持,同时降水量与灰霾呈现明显的负相关性。

Using the meteorological observations of a national base climate station in Shantou from 1980 to 2012, we analyzed the synoptic and climatological characteristics of the hazy weather in the city and determined its main affecting factors associated with the weather. The result is shown as follows. Over the 33 years, the number of hazy days in Shantou shows a generally rising trend and the hazy weather has significant seasonal difference that is the most serious in winter, followed, in turn, by spring, autumn and summer. The haze is mainly light to moderate and never reaches the heavy intensity. There are all together 176 processes of hazy weather in Shantou over the period and those that lasted for 3 d or more began to increase significantly from the 1990s. Most of the continuous hazy processes lasted for 3 to 5 d. Hazy weather usually occurs with the easterly wind and tends to form and maintain when the wind is light and the relative humidity is high. The amount of precipitation is much negatively correlated with the haze.