AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Process Analysis and Sensitivity of Air Quality to Emissions in Pearl River Delta of China using CMAQ Model
QI FAN, Wei Yu, Shaojia Fan, Jing Lan, YeRong Feng, Sun yat-sen University
Abstract Number: 50 Working Group: Urban Aerosols
Abstract In this study, a modeling system consisting of Mesoscale Model (MM5), Sparse Matrix Operator Kernel Emissions (SMOKE) and Community Multiscale Air Quality (CMAQ) model has been applied to an aerosol episode in Pearl River Delta, China. Sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3) and particulate matter (PM2.5) concentrations modeled with the finest horizontal grid resolutions (4km) were evaluated against available ground-level observations from PRIDE-PRD2004 campaigns for the period of 09-12 Oct 2004. Both MM5 and CMAQ show reasonable performance for major meteorological variables (i.e., temperature, relative humidity, wind direction, planetary boundary layer height) with normalized mean biases (NMBs) of 4.5–38.8%. The temporal variations of surface concentrations SO2, NO2, O3 and PM2.5 were captured well by CMAQ model. Relatively poor performance was found in the simulated maximum concentrations of all pollutants, the CMAQ systematically underpredicted the mass concentrations. The process analysis (PA) results showed that emissions, horizontal and vertical transport were the most important processes for PM2.5 and its secondary components. The contributions of horizontal and vertical transport processes were different during the period, but in all, these two processes contributed to the removal of air pollutants. Besides, the contributions of the same physical process were different for various pollutants, the dry deposition was vital to the removal of PM10. NOx was affected by the transport process obviously. Guided with PA results, sensitivity experiment excluding the emissions in Guangzhou city was conducted to identify the contributions to PM2.5 from local and non-local emissions.