Operational surface analysis of atmospheric pollutants over North America and plans for reanalysis

We present the latest surface analysis of atmospheric pollutants that has been operational at Environment and Climate Change Canada since 2021.  This formulation is an attemp to simplify the need for conducting a EnKF approach.  Here, past air quality forecasts is used to create an ensemble, so there is no need to compute new air quality forecasts.  The analysis is extremely fast and captures non-homogeneous, non-isotropic error correlations related to terrain related features and surface emissions.  It is superior to the scheme  that used an OI approach with prescibed homogeneous isotropic correlations as was done in the first operational implementation of an operational air quality analysis.  The new analysis scheme produces in real-time analyses of O3, NO2, PM2.5, PM10, NO and SO2 and maps of the Air Quality health Index.  A brief overview of the algorithm, the verification metric used, and a comparison with the homogeneous isotropic implementation will be presented.  Results from an onging reanalysis from 2002 to 2018  could be available at the time of the conference.