Update on NOAA's Operational Air Quality Predictions

NOAA provides operational predictions of ozone and wildfire smoke for the United States (U.S.) and predictions of airborne dust over the contiguous 48 states. Predictions are produced beyond midnight of the following day at 12 km spatial and hourly temporal resolution and are available at http:// airquality. weather. gov/. Ozone predictions and testing of fine particulate matter (PM2.5) predictions combine the NOAA National Centers for Environmental Prediction (NCEP) operational North American Mesoscale (NAM) weather predictions with inventory based emission estimates from the EPA and chemical processes within the Community Multiscale Air Quality (CMAQ) model. Predictions of smoke and dust from dust storms use the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model. Verification of ozone and developmental aerosol predictions relies on AIRNow compilation of observations from surface monitors. Verification of smoke and dust predictions uses satellite retrievals of smoke and dust. Ozone prediction accuracy is maintained in recent years, while pollution sources are changing, through updates in emission source estimates and updates in the model configuration. Emissions for operational ozone predictions were updated using EPA projections of mobile sources for 2012. Trends in NOx from satellite and ground observations show a good agreement with emission updates over large U.S. cities. Updated CMAQ model with CB05 mechanism and AERO4 aerosol module was implemented for operational ozone prediction in January 2015. Updates include monthly varying lateral boundary conditions, modified dry deposition, constraints on minimum planetary boundary height, and changes to the lifetime of organic nitrate. Testing of PM2.5 predictions from the same system modulates soil emissions by snow and ice cover, and includes emissions of windblown dust and particles emitted from forest fires. Further development of PM2.5 predictions will explore bias correction approaches. Longer-term plans include comprehensive linkages between NAQFC predictions for the U.S. and global atmospheric composition predictions, as resources allow.