福建沿海城市霾天气特征

利用2006年1月—2010年12月福建省沿海6个城市的能见度、相对湿度、降水、天气形势和大气污染物资料,对霾天气时空变化特征、霾与天气形势的关系进行了分析. 结果表明:宁德市每年霾日数最少,为12～26 d;漳州市霾日数最多,为74～118 d;而福州、厦门和泉州三市的霾日数相近.6个城市霾天气主要出现在12月—次年6月,7—11月霾的出现率极低且均以轻微霾为主,所占比例在85.5%以上；持续时间短暂的霾较多,半天和全天的霾较少. 在暖区辐合、高空槽和变性冷高压3种天气形势下霾出现频率均较高,分别达到21.2%～49.5%、9.1%～42.3%、6.1%～47.5%. ρ(PM₁₀)与能见度的相关系数最高,为-0.44~-0.33,并且各城市霾天气下的ρ(PM₁₀)均明显高于非霾天气；ρ(SO₂)除莆田市外,ρ(NO₂)除漳州市外,其他城市ρ(SO₂)和ρ(NO₂)均为霾天气高于非霾天气. 

Characteristics of Hazy Weather in Coastal Cities in Fujian Province

The temporal and spatial variation characteristics of hazy weather, and the relationship between haze and synoptic situations, were analyzed using observation data from six coastal cities in Fujian Province. The weather parameters observed from January 2006 to December 2010 included visibility, relative humidity, precipitation, synoptic situations and mass concentrations of atmospheric pollutants recorded. The results showed that the number of hazy days were the fewest in Ningde(12-26 days per year), and most in Zhangzhou(74-118 days per year), while the situations were similar in Fuzhou, Xiamen and Quanzhou cities. Hazy days mainly occurred from December to June, and rarely occurred from July to November. In general, the hazy days were mostly “short-lived,” representing 85.5% of the total hazy days in all observed cities, and were rarely “semidiurnal” or “all-day.” Hazy weather appeared frequently under the conditions of warm zone convergence, upper trough or transformed surface cold high, with probabilities of 21.2%-49.5%, 9.1%-42.3% and 6.1%-47.5%, respectively. The correlation coefficient between ρ(PM₁₀) and visibility was the highest, which was -0.44 to -0.33. ρ(PM₁₀) was higher in hazy days than in non-hazy days in all cities. ρ(SO₂) was equal in all cites except for Putian, while ρ(NO₂) was the same everywhere except Zhangzhou.