Multiscale simulations of the impact of lightning NOx on atmospheric chemistry and an investigation of the aerosol direct and semi-direct effects on lightning

Both storm-scale and global model simulations have been used to examine the impact of lightning NO production on atmospheric chemistry. A series of cloud-resolving model simulations of thunderstorms observed during different airborne field campaigns has been conducted to estimate lightning NO production, to better understand the impact of lightning on ozone mixing ratios, and to estimate the vertical distribution of lightning NO following convection for use in global chemical transport models. In these simulations, lightning NO production was calculated using observed flash rates derived from ground-based networks. We present highlights from these studies as well as the lightning observations used in the model and discuss the implications of this work for regional and global models. These results inform a series of global simulations using NASA's Goddard Earth Observing System Chemistry-Climate Model (GEOS-CCM). In the GEOS-CCM, flash rates are parameterized based on cloud microphysical properties and evaluated through comparison with the LIS/OTD lightning climatology. We will present results from GEOS-CCM simulations that assume different aerosol distributions to represent pre-industrial, current, and future conditions in order to investigate the climatic impact of aerosol direct and semi-direct effects on lightning NO production and atmospheric chemistry.