A REAL-TIME OPERATIONAL FORECAST MODEL FOR METEOROLOGY AND AIR QUALITY DURING PEAK AIR POLLUTION EPISODES IN OSLO, NORWAY

摘要

A real-time operational forecast model for meteorology and air quality for Oslo, Norway is presented. The model system consists of an operational meteorological forecasts model and an air quality model. A non-hydrostatic model operated on two different domains with 1 and 3 km horizontal resolution is nested within the routine meteorological forecast model, which is run for North West Europe with 10 km horizontal resolution. The meteorological data are applied to an air quality model of Oslo with a 1 km grid and sub-grid treatment of line and point sources. Results from 22 days during the winter season 1999―2000 are presented and discussed. Prediction of wind speed and directions and relative humidity are clearly improved by increasing the horizontal resolution of the meteorological model. Temperature inversion strengths are however considerably overestimated. The predictions of PM_(10) corresponds best with measurements on winter days with wet or frozen surfaces in the city. On dry days, especially during spring time with a large deposit of accumulated dust on the roadside, the model under predicts the PM_(10) concentrations considerably. It is in particular recommended to improve the description of the PM_(10) source strength in order to enhance the precision in the air quality forecasts.