CMAQ模式及其修正预报在珠三角区域的应用检验

为检验CAMQ空气质量数值预报模式对区域性空气质量的预报准确度,通过对珠江三角洲地区16个监测站点数据进行聚类分析,对划分的评价区域进行预报误差分析。结果表明,CMAQ模式输出的污染物浓度水平存在明显偏低的现象,且可吸入颗粒物的浓度偏离最大,这与污染源清单削减程度有关。污染物浓度时变规律分析表明,CMAQ模式能较好地模拟可吸入颗粒物、二氧化氮和臭氧小时浓度的日变化特征,但对二氧化硫的模拟能力较弱,反映污染源时间分配因子存在不适应性。为提高预报的初始浓度值,采用预报日前一天的监测数据作为修正项,并考虑CMAQ模式预报的浓度变化趋势,从而进行修正预报。误差统计表明,修正预报的准确度显著提高,反映了引入实际监测数据对空气质量数值预报模式进行修正的研究意义和可行性。

Application and Verification of CMAQ Model and Revision Forecast in Pearl River Delta Region

Several evaluation regions were identified to examine the accuracy of CAMQ air quality forecasting model in regional air quality forecast,via cluster analysis of observed data at 16 monitoring sites in Pearl River Delta Region.Error analysis to these evaluation regions indicated that the pollutant concentrations from CMAQ model were obviously lower than observation value,especially PM10 simulation,because of emission inventory reduction.Pollutant concentration time-variable analysis indicated that CMAQ model can simulate daily variation characteristics of PM10,NO2 and O3 well,but is weak for SO2,which reflects inadaptability of emission time variant factors.To enhance initial concentration of forecasting,the observed data at previous day was used as a correction term to form a revision method with the predicted variation tendency from CMAQ model.Error statistics indicated that the revision forecasting accuracy obviously enhances,which reflects the significance of the method.