Based On The Models - 3 / Cmaq Air Quality Forecast Method Research

Faced with the reality of serious environment pollution increasingly, introduction of intelligent models and dynamic service composition is major means and main ways to improve air quality forecasting performance. The U.S. Environmental Protection Agency developed Community Multiscale Air Quality(CMAQ) modeling system is the third-generation air quality system. CMAQ is designed for applications ranging from supervision and policy analysis, which is helpful to understanding the complex atmospheric chemistry and physics interactions. The Models-3/CMAQ provide scientific basis of localized application, it’s effective for improving chinese air quality system forecasting level and controlling pollution concentration in urban area.Based on numerical simulation and forecasting of air quality, Models-3/CMAQ modeling system and cloud computing platform in Hadoop, this paper has done the following as deep research and work:(1) Introduce Models-3/CMAQ and cloud computing concepts, work mechanism and modeling skills. Set up the MM5-SMOKE-CMAQ air quality modeling system in the Fedora Linux platform system. Use download test data to assess the air quality forecasting capability. The results show reasonable consistency and good correlation in the spatial distribution of NOx. Conclude Models-3/CMAQ, which has increased the flexibility with multiscale modular structure, is the better model to solve air pollutant problem.(2) Analyze the air quality forecasting steps and methods in Hadoop. In cloud computing environment, combine the third generation air quality modeling system and Hadoop-MapReduce programming model. Use download test data to compare O3data deviation in different hardware and software environment. The efficiency of Models-3/CMAQ significantly improve in cloud computing environment, and air quality forecasting operation and performance are normal. The results clearly reflect O3spatial and temporal distribution characteristics, different computing environments do not affect CMAQ simulation and operation.(3) Compare meteorological inputs for Models-3/CMAQ by MM5and WRF model, analyze the key air quality forecasting meteorological elements of which impact CMAQ. In the same initial field and boundary condition, the meteorological elements simulated by WRF are better than those by MM5. The new model can improve the accuracy of air quality modeling system, reducing forecasting error.