苏州城市灰霾及气溶胶对大气消光贡献的模拟研究

Numerical simulation of the urban haze and the contribution of aerosol to ambient light extinction in the Suzhou area,Jiangsu,eastern China

利用南京大学空气质量模式(NJU-CAQPS)对苏州地区2010年1、4、7、10月中旬共19d灰霾状况进行数值模拟,PM10、PM2.5、能见度等参数的模拟日平均与观测值模拟日平均比值分别为0.9、1.1、0.9.苏州北部郊区局地PM10、PM2.5严重超标,硫酸盐、硝酸盐等二次气溶胶浓度高值区位于主城区西部;模拟期间(总共456h)中有99h出现灰霾,发生率为21.7%,主城区西部最容易发生灰霾;城区硫酸盐对消光系数的贡献率最高,为39.1%,硝酸盐、有机物、黑碳的贡献率分别为15.6%、18.3%和10.0%(明显高于郊区).

Nanjing University City Air Quality Prediction System（NJU--CAQPS）is used to simulate haze weather in Mid January, April,July and October. The ratios of PM10, PM2.5 , visibility, etc. between the simulated values and the observed values are 0.9,1.1, and 0.9 respectively. The suburb area in northern Suzhou suffers from high value of PM10 and PM2.5 beyond the threshold, the concentration of sulfate and nitrate has hot spot on west side of city. During the 456 simulation hours, there are 99 hours that haze occurred, which ＇covers 21.7% of total time. Sulfate in downtown area contributes the most to extinction coefficients, with ratio of 39. 1%, nitrate, organics and black carbon respectively contributes 15.6 %, 18.30% and 10.00%, which are significant higher than those in suburb area.