In chemical transport models, NOx
emitted by lightning (LNOx
) is instantaneously diluted into the grid. A plume-in-grid parameterization to account for the sub-grid chemistry of LNOx
is presented. This approach was implemented into the GEOS-Chem model and leads to a relative increase of NOx
(18 % and 2 %, respectively, in July) on a large scale downwind of lightning emissions and a relative decrease (25 % and 8 %, respectively, over central Africa in July) over the regions of emissions.