15 Years of Air Quality (AQ) Objective Analysis Mapping over North America Using Real-Time Observations and Canadian Operational AQ Forecast Models

Abstract

The Regional Deterministic Air Quality Analysis (RDAQA) is a mapping of surface air pollutant concentration which combines numerical forecasts from the Regional Air Quality Deterministic Prediction System (RAQDPS) and hourly AQ observational data from monitoring surface networks over North America. These include Canadian measurement networks operated by the provinces, territories, and some municipalities and those networks covering the continental United States under the umbrella of EPA’s national AIRNow program. The model forecasts and observations are combined based on an optimal interpolation algorithm. The current RDAQA has a horizontal spatial resolution of 10 km and is issued every hour. It provides our best knowledge of the current state of the atmosphere for surface pollutant concentration for chemical species like: ozone, NO2, NO, SO2, PM2.5 , PM10. The RDAQA also provide a mapping of the Air Quality Health Index (AQHI) in quasi-real time and can be used by meteorologists in Environment Canada’s regional forecast offices to inform the public on a daily basis about the health risk associated to short term exposure to air pollution. The RDAQA products available over an extended period of time can also be used by Health Canada and health consortium partners to study how Air Quality and other multiple environmental factors are linked to a wide range of health outcomes. A description of the RDAQA will be presented as well as data access and future plans.