Estimates of lightning NO x production based on high-resolution OMI NO 2 retrievals over the continental US
Abstract. Lightning serves as the dominant source of nitrogen oxides ( NO x = NO + NO 2 ) in the upper troposphere (UT), with a strong impact on ozone chemistry and the hydroxyl radical production.
However, the production efficiency (PE) of lightning nitrogen oxides (L NOx ) is still quite uncertain (32–1100 mol NO per flash).
Satellite measurements are a powerful tool to estimate L NOx directly compared to conventional platforms.
To apply satellite data in both clean and polluted regions, a new algorithm for calculating L NOx has been developed that uses the Berkeley High-Resolution (BEHR) v3.0B NO2 retrieval algorithm and the Weather Research and Forecasting model coupled with chemistry (WRF-Chem).
L NOx PE over the continental US is estimated using the NO2 product of the Ozone Monitoring Instrument (OMI) data and the Earth Networks Total Lightning Network (ENTLN) data.
Focusing on the summer season during 2014, we find that the lightning NO2 (L NO2 ) PE is 32±15  mol  NO2 per flash and 6±3  mol  NO2 per stroke while L NOx PE is 90±50  mol  NOx per flash and 17±10  mol  NOx per stroke.
Results reveal that our method reduces the sensitivity to the background NO2 and includes much of the below-cloud L NO2 .
As the L NOx parameterization varies in studies, the sensitivity of our calculations to the setting of the amount of lightning NO (LNO) is evaluated.
Careful consideration of the ratio of L NO2 to NO2 is also needed, given its large influence on the estimation of L NO2 PE.