苏州灰霾特征分析

利用苏州市2009年6月-2010年5月逐时的能见度、相对湿度、污染物(PM1o、PM2.5、黑碳)浓度和散射系数等资料进行灰霾的判识与统计分析,结果表明:苏州市灰霾日占全年天数的46.6％,雨日和“蓝天”分别占33.2％和21.9％.在苏州所有灰霾日中以轻微灰霾为主,占灰霾曰总数的70.6％,发生中度和重度灰霾的频率较小.灰霾出现频率的日变化规律表明白天出现灰霾的频率比夜间低,在5-8时灰霾出现的频率达到峰值,14-16时灰霾出现的频率最低.灰霾日的污染物浓度远大于非灰霾日,随着灰霾等级增大,黑碳浓度明显增大；除重度灰霾外,PM10和PM2.5浓度也明显增大；散射系数增大.

Characteristics of haze in Suzhou

Characteristics of haze in Suzhou were analyzed using data of the hourly visibility, relative humidity, concentration of pollutants (including PM₁₀, PM_2.5, BC(black carbon))and scattering coefficient from June 2009 to May 2010. The result showed that the total haze days accounted for 46.6 percent of the whole year days; rainy and blue days accounted for 33.2 percent and 21.9 percent respectively. Among all haze days, slight haze weather accounted for 70.6 percent of the total haze days, occurred the most frequently, while moderate and serious haze weather occurred rarely. Haze exhibited a significant diurnal variations, which occurred less often in the daytime than in the nighttime, the largest frequency of haze appeared at 5-8 a.m, and the least appeared at 14-16 p.m. Compared with non-haze days, the concentration of pollutants was higher in haze days. With the level of haze increased, the concentration of black carbon increased obviously; except serious haze days, the concentration of PM₁₀, PM_2.5 also increased, as well as the scattering coefficient.