Lightning NOx Production in the Tropics as Determined Using OMI NO₂ Retrievals and WWLLN Stroke Data

Nitrogen oxide (NO x ) production by lightning in the tropics is estimated using tropospheric NO x amounts (LNO x *) over deep convective grid boxes derived from Ozone Monitoring Instrument (OMI) nitrogen dioxide (NO 2 ) slant columns and detection‐efficiency–adjusted World Wide Lightning Location Network (WWLLN) flashes. The lightning NO x production efficiency (LNO x PE) in the tropics is determined for the austral and boreal summers of 2007 to 2011 by regressing regional mean daily values of LNO x * for individual seasons against daily flash totals during flash windows prior to the OMI overpass. LNO x PE is determined to be approximately two times larger over marine locations than over continental locations possibly because marine flashes are more energetic. Overall, the mean LNO x PE for the tropics is calculated to be 170 ± 100 mol per flash with values over the tropical Pacific (low flash rate region) being largest. The main contributors to uncertainties in PE are uncertainties in WWLLN flash detection efficiency, upper tropospheric NO x lifetime in the near field of convection, and air mass factor biases.