New Bias-Corrected Ozone Predictions for NOAA's National Air Quality Forecast Capability

This presentation will provide an overview of recent updates to NOAA’s operational air quality predictions with a focus on operational ozone guidance. The NOAA National Air Quality Forecast Capability (NAQFC) relies on an implementation of the Community Multiscale Air Quality (CMAQ) modeling system linked with the North American Mesoscale (NAM) model to provide predictions for ozone and fine particulate matter (PM 2.5) over the United States (U.S.). Dispersion predictions using NOAA’s HYbrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model provide wildfire smoke guidance over the U.S.; and predictions of airborne dust over the contiguous 48 states. Ozone, smoke and dust predictions are available at http://airquality.weather.gov and as a web service at https://idpgis.ncep.noaa.gov/arcgis/rest/services/NWS_Forecasts_Guidance_Warnings. Dissemination of PM 2.5 and bias corrected ozone predictions to the public is planned following our next implementation.

The most significant recent update is the addition of a post-processing scheme for ozone predictions based on reducing biases identified for similar (analog) historical predictions. The approach we are taking is unified with that used for bias-correction of PM 2.5 predictions, except that it additionally relies on NOx, NOy and ozone as parameters to identify analogs. Updates to the PM 2.5 bias correction system include the use of a consistent training model prediction data set for the unified Kalman Filter Analog (KFAN) method and an increased number of observation sites for PM 2.5 bias correction to an average of over 900 monitors. The bias-correction scheme is modified for the prediction of extreme events for ozone and PM 2.5 by adding the difference between the current raw model forecast and historical analogs mean to the KFAN bias-corrected predictions. Anthropogenic emission upgrades include recent monitoring data for point sources and oil-and-gas industrial activities. Additional updates to include National Emission Inventory (NEI) 2014 version 2 are being tested in two versions of CMAQ (v. 5.0.2 and v. 5.2). Another area of recent focus has been modification of the way wildfires are identified and their emissions included in NOAA’s air quality predictions. We will present impacts of these recent updates and discuss future plans.