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3rd Annual CMAS Models-3 Workshop October 18-20, 2004 Chapel Hill, NC. Applications of Models-3 in Coastal Areas of Canada. M. Lepage, J.W. Boulton, X. Qiu and M. Gauthier RWDI AIR Inc. C. di Cenzo Environment Canada, P&YR. Modelling Domains. (4-km). (4-km). Factors to be considered:.
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3rd Annual CMAS Models-3 WorkshopOctober 18-20, 2004 Chapel Hill, NC Applications of Models-3 in Coastal Areas of Canada M. Lepage, J.W. Boulton, X. Qiu and M. Gauthier RWDI AIR Inc. C. di Cenzo Environment Canada, P&YR
Modelling Domains (4-km) (4-km)
Factors to be considered: • Meteorological fields (MM5, MC2…) • Emission inventory and modeling • CMAQ Chemical mechanism (SAPRC-99, CB-IV & RADM2…) • Grid resolution and domains • Monitoring data and evaluation methods
Western Canada: • MC2, SMOKE, CMAQ • Modeled events: Aug ’01, Dec ‘02 • 4 km grid in MC2 (from UBC) • Emission Inventories: 2000 (GVRD), 1995 (BC), 1999 (US), BEIS3 • 12 km, 4 km grids in CMAQ • RADM2, SAPRC99
Pitt Meadows Modelled & Observed Time Histories Ozone, Aug. 9 – 20, 2001 ppb Day ppb ppb Better nighttime ozone Nighttime ozone sensitive to grid resolution… Day Day
Pitt Meadows Modelled & Observed Time Histories Ozone, Aug. 9 – 20, 2001 (cont’d) ppb Ozone Under-prediction Day ppb NO2 NO2 Good NO2 Predictions Recent tests suggest better results with SAPRC99… Day
Modeled & Observed Time Histories: PM2.5, Aug. 9 – 20, 2001 PM2.5 (µg/m3) Too strong diurnal circle No2 (ppb) p-nitrate (ug/m3) Precursor diurnal Pattern propagated to secondary PM
Eastern Canada: • MM5, SMOKE, CMAQ • Modeled events: Jul ’99, Aug ‘01 • Emission Inventories: 1995 (EC), 1999 (US), BEIS3 • 36 km, 12 km, 4 km grids in CMAQ • CB4, SAPRC99
Ozone Model Performance: Ozone Time Histories for Nearby, 4-km Resolution Urban (red) and Suburban (green) Monitoring Sites, Hamilton, Ontario Daytime obs ozone the same at both sites Predicted (blue) nighttime ozone aligns better with the suburban monitoring site
PM2.5 Model Performance: PM2.5 Time Histories for Nearby, 4-km Resolution Urban (red) and Suburban (green) Monitoring Sites, Hamilton, Ontario Sulfate dominated aerosol: precursor diurnal cycles not propagated.
CMAQ Performance • Hourly and daily Ozone predictions are overall reasonably good in western and eastern Canada, (sometimes poor at night) • Kz(min) could be a contributing factor? • Grid resolution is important for ozone predictions, especially at nighttime (NOx): higher resolution is better • Meteorological inputs can be a major factor • Chemical mechanism also plays a role
CMAQ Performance (cont’d) • Daily mean PM predictions are reasonably good in western and eastern Canada • Hourly values are generally poor, but somewhat better for Eastern Canada • SOA module could be a contributing factor? • Better biogenic emissions and temporal factors are needed, especially in western Canada due to biogenic SOA. • Meteorological inputs can be a major factor • Chemical mechanism also plays a role
MM5 or MC2 can produce the necessary meteorological inputs. However, there is uncertainty in PBL predictions relating to: • Model grid resolution • Geophysical fields • Initial and boundary conditions • Microphysics and convective parameterization schemes • PBL and surface schemes • ???
MC2 Sensitivity Study Sensitivity tests on 4 km and 2 km grid resolutions (13 runs) combining: • 24km GEM output as initial fields • ISBA surface scheme • Kain-Fristch deep convective scheme • Kong-Yau microphysics scheme • Improved geophysics resolution • Increased vertical grid resolution
CONCLUSIONS • Reasonably good performance for 1-hr and 24-hr ozone and 24-hour PM2.5 • Better ozone diurnal pattern on 4 km grid than on 12 km grid • Working on improvements to meteorological fields • Problems with PM and SOA chemistry – now working with SAPRC99