长江三角洲地区大气O3和PM10的区域污染特征模拟

以TRACE-P污染源资料及上海市地方排放清单为基础，采用Models-3/CMAQ环境空气质量模型和中尺度气象模式MM5，模拟研究了2001-01和2001-07长三角近地面二次污染物O₃及PM₁₀的浓度分布及输送状况，并以上海市国控点2001年冬、夏季各10 d的小时监测数据对模型进行了验证.验证结果显示，Models-3/CMAQ对O₃和PM₁₀的模拟结果与监测值的相关系数分别为0.77和0.52；一致性指数分别达到0.81和0.99.模型对O₃小时最高浓度的估算偏低27%，标准偏差为-3.1%；对PM₁₀小时平均浓度的估算偏低10%，标准偏差为46%.模型已具备再现和模拟长三角大气污染输送过程的能力，且误差落在可接受的范围之内.模拟结果显示，2001-07长三角区域16个主要城市中，有14个城市O₃小时最大浓度超过国家二级标准，高浓度O₃可覆盖苏南和浙北广大区域.2001-01泰州、扬州、南京、镇江、常州等城市受本地排放源和北部大气污染输送的影响显著，大气PM₁₀日均浓度超过PM₁₀国家二级标准.长三角地区环境空气质量与污染类型受大气污染传输与化学转化的影响十分明显.夏季太阳辐射较强时，南部城市排放的污染物常以二次污染物的形式影响下风向城市；太阳辐射较弱的情况下，则以一次污染物输送为主的形式影响周边地区.冬季长三角区域颗粒物污染总体水平较高，这与我国北方地区排放的颗粒物在西北风作用下向长三角输送造成的影响密切相关.长三角地区的大气污染已逐渐从局地转为区域问题.

Regional Air Pollution Characteristics Simulation of O3 and PM10 over Yangtze River Delta Region

Based on the TRACE-P emission data and a Shanghai local emission inventory, the regional air quality model Models-3/CMAQ was applied with the mesoscale model MM5 to simulate the distribution and transport status of O3 and PM10 in the Yangtze River Delta (YRD) in January and July 2001. Ten days' hourly monitoring data at Shanghai monitoring sites were used to verify the model performance. Results show that the correlation coefficients between monitoring and simulation data of O3 and PM10 are 0.77 and 0.52, and the indices of agreement reach 0.81 and 0.99, respectively. The Models-3 simulation shows a 27% underestimation of the maximum O3 hourly concentration, but performs well in average O3 hourly concentration simulation with a normalized bias of -3.1%. The model shows a 10% underestimation of the average PM10 hourly concentration, with a normalized bias of 46%. Models-3/CMAQ has the ability to simulate the processes of air pollution transport in the YRD, and the model results are acceptable. Among the 16 major cities of the YRD, the maximum O3 hourly concentrations in 14 cities exceed the class II Chinese National Ambient Air Quality Standard (CNAAQS). The high O3 concentration area covers most of the south Jiangsu and north Zhejiang Province. Influenced by local emissions and northerly air pollution transport, the daily average concentrations in Taizhou, Yangzhou, Nanjing, Zhenjiang and Changzhou cities during January of 2001 exceed the Class II national standard. Air pollution transport and chemical transformation are quite obvious in the YRD. In summer, under strong radiation conditions, the air pollutants emitted from southern cities usually impose a negative impact on the downwind cities, due to secondary pollution formation; while under weak radiation conditions, the pollutants impact the surrounding area with primary pollution. In winter, the particle pollution level in the YRD is relatively high, which is closely related to the transportation of particulates from the north area to the YRD. The air pollution in the YRD has developed as a regional problem, rather than just a local one.