NOAA Air Quality predictions and challenges in large cities
Recent updates to operational air quality products at NOAA have focused on mobile emissions using the projections of mobile sources for 2012. All area, mobile and point emissions from Canadian sources were updated to 2006 Environmental Canada Inventory. Emission inventories are complex and take years to assemble and evaluate causing a lag of information for 4-6 years. NAQFC recently began combing inventory information with projections of mobile sources. Evaluation of NOx emissions over large cities in the US was performed. Satellite and ground observations were used to compute NOx trends, which were used to evaluate the emission updates for NAQFC operation. Evaluation of NOx emissions used in NAQFC predictions and comparison with satellite observations and surface observations shows that they are in good agreement over large cities in the US.
Recent testing has been focused on transitioning CMAQ model with updated CB05 chemical mechanism into operations for ozone predictions. Developmental testing of aerosol predictions with NEI inputs using CB05 chemical mechanism and AERO-4 aerosol modules continues to show seasonal biases – overprediction in the winter and underprediction in the summer. Current efforts are focusing on inclusion of bias correction for fine particulate matter (PM2.5) and development of linkages with global atmospheric composition predictions.