Assessing the Impact of Lightning Assimilation and Lightning NOx on Air Quality for the 2016 CMAQ Annual Simulations over the Contiguous United States

The Community Multiscale Air Quality (CMAQ) model is gearing up to have its version 5.3 released next year and a comprehensive evaluation plan is underway for the release. The planned 2016 annual simulations will include the lightning assimilation to characterize cloud field in the Weather Research Forecast (WRF) model that provides the meteorological inputs for CMAQ and lightning NOx emissions in CMAQ. Significant impact of lightning assimilation and lightning NOx on air quality prediction using the earlier versions of WRF and CMAQ for different years were noted. Taking advantage of this annual model simulation effort with updated WRF and CMAQ models for the calendar year 2016, we will quantify the contribution of lightning NOx emissions to the total NOx emissions budget and assess its spatial and temporal impacts on air quality predictions. The model performance with/without lightning NOx will be evaluated using ground-level observations from monitoring networks and vertical structures will be gauged using available ozone-sonde and Lidar observations. Comparisons with similar studies using earlier model versions and different years will also be presented to help characterize the variability in lightning activity and its impacts on simulated air quality.