Recent Advances in Canada's National Operational AQ Forecasting System

Abstract

Environment Canada routinely issues twice-daily, 48-h public forecasts of (a) gridded surface and near-surface O3, PM2.5, and NO2 concentration fields made by the GEM-MACH15 on-line chemical weather forecast model on a 15-km North American grid plus (b) point-specific forecasts for Canadian cities of the national Air Quality Health Index (AQHI) prepared by a statistical postprocessing package called UMOS-AQ. The AQHI is a health-based, additive, no-threshold, hourly AQ index that ranges from 0 to 10C and is based on a weighted sum of local O3, PM2.5, and NO2 concentrations. An objective analysis scheme for surface O3, PM2.5, and NO2, which will provide model-measurement data fusion and model error diagnostics, is now being tested. These recent advances as well as plans for further improvements to the AQ forecasting system are described. © Springer Science+Business Media Dordrecht 2014.