Application of MM5 and CAMx4 to local scale dispersion ofparticulate matter for the city of Christchurch, New Zealand

摘要

A numerical model – Mesoscale model (MM5) – is used in conjunction with the 3-dimensionalrnEulerian/Lagrangian dispersion model (CAMx4) to model PM10 dispersion for a period of 48 hours forrnthe city of Christchurch, New Zealand. In a typical winter, Christchurch usually experiences severerndegradation in air quality. The formation of a nocturnal inversion layer during stagnant synopticrnconditions, and the emissions of particulate matter (PM10) mainly from solid fuel home heatingrnappliances (‘Domestic’ factor) leads to severe smog episodes on about 30 nights each winter. Thernmodelling results from the highest resolution computational grid are compared with the observedrnmeteorology and dispersion for winter 2000, when the Christchurch Air Pollution Study (CAPS2000)rnwas underway. Results from a case study in 2003 are also shown. The numerical modelling system isrnable to simulate surface-layer meteorology and PM10 spatial distribution with a good level of skill (I.e.rnIndex of Agreement and Pearson’s Correlation Coefficient > 0.8 for PM10).