250 likes | 380 Views
CMAQ PERFORMANCE AND ASSESSMENT OF THE TRANSBOUNDARY INFLUENCES DURING LONG-TERM MODELLING IN ONTARIO. Andrei Chtcherbakov, Robert Bloxam, David Yap, Duncan Fraser, Neville Reid, Sunny Wong Ontario Ministry of the Environment, Toronto, Canada 3rd Annual Models-3 User's Conference
E N D
CMAQ PERFORMANCE AND ASSESSMENT OF THETRANSBOUNDARY INFLUENCES DURING LONG-TERM MODELLING IN ONTARIO Andrei Chtcherbakov, Robert Bloxam, David Yap, Duncan Fraser, Neville Reid, Sunny Wong Ontario Ministry of the Environment, Toronto, Canada 3rd Annual Models-3 User's Conference October 18-20, 2004Chapel Hill, NC
Modelling Approach The modelling has been done for the May through September 1998 period. The modelling was done for a base case and then with Ontario’s anthropogenic emissions shut off. Evaluation of the modelling results ( base case) for ozone and PM2.5 were made in 12 major Ontario communities. Assessment of transboundary influences were made both during high concentration episodes and on cleaner days.
Evaluation of CMAQ Performance • Analysis of time series and frequency distributions for modelled and observed data in each subdomain separately for every month • Detailed investigation of modelled/observed discrepancies ( backtrajectory analysis, satellite images, etc.) • Analysis of chemical composition of PM2.5 • Analysis of correlation between observed/modelled data
Time series of ozone concentrations , GTA______ - modelled ______ - observed O
Time series of PM2.5 concentrations, GTA______ - modelled ______ - observed
Number of days with high O3 ( > 65 ppb) and PM2.5 ( > 20 ug/m3) concentrations
O3 and PM2.5 concentrations on “Clean”, “Dirty” days and on average
Percent change in Windsor with Ontario emissions eliminated OOzone PPM2.5
Percent change in the GTA with Ontario emissions eliminated Ozone PPM2.5
Conclusions • The modelling assessment has been performed for both ozone and PM2.5 over a 5 month period in 1998 • Although there were some discrepancies between modelled and observed data for individual days and episodes, the differences appear to be random due to small shifts in the meteorological fields. • The model/monitoring comparisons indicate that the model performed well overall. • Zeroing-out Ontario’s emissions showed small impacts in southeastern Ontario with larger influences on PM2.5 in the GTA/Hamilton areas and on ozone east of the GTA.