多模式模拟评估奥运赛事期间可吸入颗粒物减排效果

以空气质量多模式系统为工具,分析奥运赛事期间可吸入颗粒物(PM10)浓度大幅减小特征,从气象场和排放源两方面研究PM10浓度大幅减小的主要原因.多模式系统由嵌套网格空气质量模式(NAQPMS)、通用空气质量多尺度模式(CMAQ)和复杂大气空气质量三维模式(CAMx)3个空气质量复合模型组成,并以中尺度气象模式(MM5)和稀疏矩阵排放处理模型(SMOKE)提供统一气象场及排放源.研究对比2006年8月、2008年8月两组气象条件下北京PM10浓度水平及模拟效果,结果表明奥运赛事期间PM10浓度大幅减小的主要原因不是气象因素,而是由于额外措施引起的PM10排放减少.同时采用多模式系统数值模拟反向评估,获得北京奥运赛事期间奥运控制及额外减排措施引起的PM10减排量,结果表明,奥运赛事期间所有额外控制措施对颗粒物浓度效果相当于在2008年8月气象条件下,削减大约200t.d-1的无组织PM10排放,相当于北京正常时期PM10排放的50%.

Multi-model simulation of PM10 during the2008 Beijing Olympic Games:Effectiveness of emission restrictions

The cause of the decrease of respirable suspended particulate matter (PM10) concentrations over Beijing during the Olympics 2008, is examined using the multi-models air quality system consisting of the Nested Air Quality Prediction Modeling System (NAQPMS),the US/EPA Community Multiscale Air Quality (CMAQ) modeling system and the three dimensional Comprehensive Air Quality Model with extensions (CAMx). The multi-models simulations are processed with same meteorological field and same emissions inventory provided respectively by the fifth-generation NCAR/Penn State Mesoscale Model (MM5) and the Sparse Matrix Operator Kernel Emissions (SMOKE). Comparing predicted ensemble PM10 concentrations over Beijing under the meteorological conditions in August in 2006 and 2008, it indicates that PM10 concentrations decrease during the Olympic Games is mainly triggered by emissions reduction due to additional strengthened control measures. The multi-models simulations performed under reduced emissions condition show that all implemented measures during the Olympic Games correspond to a reduction of PM10 loading of about 200 tons per day under the meteorological conditions in August 2008. This corresponds to about 50% reduction of PM10 emissions in Beijing.