7.3 Impact of Lightning-NO and Radiatively-Interactive Ozone on Air Quality over CONUS, and their Relative Importance in WRF-Chem

Martini, Matus and Dale Allen, University of Maryland, College Park, MD, Kenneth Pickering, NASA GSFC, Greenbelt, MD, Amanda Hansen, SAIC, Barry Baker, University of Maryland Baltimore County

Global chemistry climate models include the coupling of ozone with radiation. In this study, we investigate the chemistry-radiation feedback of ozone on a regional scale by allowing two-way interaction between chemistry transport and radiation. This study employs the following new approaches: 1. WRF-Chem simulations are driven by NASA’s MERRA reanalysis. 2. Initial and boundary conditions for chemical species are taken from NASA’s global chemical transport model GMI with combined stratospheric and tropospheric chemistry (two separate simulations of GMI, also driven by MERRA, with and without lightning-NO emissions). 3. We use the most recent segment altitude distributions of VHF sources from the Northern Alabama Lightning Mapping Array to best represent the vertical distribution of lightning-NO. 4. We use a look up table that utilizes convective precipitation and mixed phase depth to estimate total flash rates over the continental United States (CONUS). 5. We include interactive ozone in longwave and shortwave radiation schemes. We conduct four sensitivity simulations over the CONUS, two with lightning-NO and two without, each two with interactive and non-interactive ozone. The WRF-Chem simulations are compared to ozonesonde, satellite (OMI, TES) and ground-based observations (CASTNET, AQS). The goal of the simulations is to determine whether adding lightning-NO emissions requires coupling of ozone with radiation in WRF-Chem.