Assessment of Lightning Assimilation and Lightning NO in the WRF-CMAQ Modeling System Using WWLLN Lightning Flash Data

Lightning assimilation is effective to reduce errors associated with convective rainfall and other convection-related meteorological variables. While lightning-induced nitrogen oxide (LNO) is one of the most important natural sources for nitrogen oxides (NO_x) that regulate tropospheric ozone (O₃) production and influence the oxidizing capacity of the atmosphere. Lightning assimilation and LNO have been implemented in the Weather Research and Forecasting (WRF) and Community Multiscale Air Qualtiy (CMAQ) coupled modeling system with lightning flash data from National Lightning Detection Network (NLDN) over the continuous United States. However, with applications being extended from regional to global scales, the global lightning data are required to perform lightning assimilation and produce LNO for air quality modeling applications beyond the regional scales. As a preliminary study to set the stage for global applications, the lightning flash data from the World Wide Lightning Location Network (WWLLN) will be applied for lightning assimilation and LNO production in the updated two-way coupled WRF (version 4.1)-CMAQ (version 5.3) modeling system for 2016 over the contiguous US. The meteorological fields such as precipitation, 2-m temperature, water vapor mixing ratio, wind speed, and wind direction will be assessed against ground observations and the impact on air quality will be evaluated using data from surface monitoring networks as well as aloft measurements.