华中区域环境气象数值预报系统及其初步应用

Development and Preliminary Application of Environmental Meteorology Numerical Model System in Central China

基于WRF/Chem大气化学模式建立了华中区域环境气象数值预报系统,初步应用在武汉市大气污染物浓度数值预报中,并与CUACE全国环境气象模式产品预报进行比较,最后通过试验探讨了一种大气污染调控方案。结果表明,模式系统较好地验证了武汉市大气污染物浓度日变化及空间分布特征,对PM10、PM2.5、SO2、NO2、CO浓度变化趋势及误差稳定性预报较好,平均绝对百分误差MAPE控制在20%~40%,冬季O3预报出现系统正偏差,但趋势预报较好。区域WRF/Chem模式对武汉市的大气污染物浓度预报效果要优于CUACE模式系统,可为武汉市空气质量预报提供更具有参考价值的模式指导产品。此外,试验探讨了污染源排放速率的优化调控方案,依据大气边界层高度日变化特征,通过动态调控一天中不同时段的污染源排放速率,调度日间最大排放至大气稀释扩散的有利时段,在不消减日排放总量的情况下,也可以减少大气污染。

In order to support central China environment meteorological prediction services,and protect environment reducing air pollution,the environmental meteorology numerical model system was developed basing on the regional chemical dynamical model（WRF/Chem）. It could provide the numerical forecasting product of air quality for regional environment. The system was preliminary applied in numerical prediction of air pollution in Wuhan at present,and was compared with CUACE forecast products. In addition,an air pollution optimal control plan was discussed through this test. The results showthat：The numerical simulation results of model system could validate the temporal variation and spatial distribution of the air pollutants concentration in Wuhan.The population correlation coefficients and the forecasting effectiveness of PM10,PM2.5,SO2,NO2,CO concentrations were credible,and the mean absolute percentage error（MAPE）was controlled in 20% ~ 40%. The O3 concentration correlation coefficient was satisfactory,but the forecast results appeared positive deviation in winter. Compared with CUACE forecast products of every 3 hours concentrations of six air pollutants in Wuhan from September 2014 to January 2015,WRF/Chem products was better. It means that WRF/Chem was more referential value for the air quality forecast in Wuhan. Furthermore,an optimal adjustment test for air pollution control was tentative discussed by changing hourly emissions of pollution source. It suggests that without reduction of daily total emission,the air pollutants concentration can be reduced to some extent by changing the diurnal variations of the emissions according to the characteristics of atmospheric boundary layer height at different times of the day. In the later,we will collect longer observation data in more cities,and evaluate the accuracy and stability of WRF/Chem system.