Observations of Lightning NO_x Production From GOES‐R Post Launch Test Field Campaign Flights

Abstract

Lightning produces nitrogen monoxide (NO) as the extreme temperatures (>20,000 K) in lightning channels dissociate molecular oxygen (O 2 ) and molecular nitrogen (N 2 ) forming NO, which quickly reacts with ozone (O 3 ) to form nitrogen dioxide (NO 2 ) (Zel'dovich et al., 1947). The nitrogen oxides (NO x ; NO + NO 2 ) produced by lightning (LNO x ) play an important role in determining mid-and upper-tropospheric concentrations of the hydroxyl radical (OH, the atmosphere's cleanser), methane (CH 4 , an especially potent greenhouse gas),

Observations of Lightning NOx Production From Tropospheric Monitoring Instrument Case Studies Over the United States

“…Justification for use of the 10th and 30th percentiles is given in the last paragraph of Section 3. The uncertainty associated with tropospheric background is higher in this study than in Allen et al (2021) because the tropospheric columns from TROPOMI are of coarser spatial resolution than those from GCAS. The uncertainty associated with advective loss is assumed to be given by the coefficient of variation of the advective adjustment term shown in Table 2, which is 14%.…”

“…In this study as in Allen et al. (2019, 2021) and Bucsela et al. (2019), PE values are assumed to be biased high by 20% due to bases in AMF arising from positive biases in modeled NO/NO 2 ratios in the upper troposphere.…”

“…Applying these values to the GLM16 and ENTLN PEs shown in Table 3 results in final PEs of 175 ± 100 mol per flash for optical flashes based on GLM16 and 120 ± 65 mol per flash for sferic-based flashes from ENTLN. Allen et al (2021) obtained a considerably higher PE of 360 ± 180 mol per flash for GLM16 and 230 ± 115 mol per flash for ENTLN assuming τ equals 2 h and cancellation of biases. However, their PE would be 230 ± 115 mol per flash for GLM16 and 150 ± 75 mol per flash for ENTLN if they also assumed 3 h for τ and a 20% high bias.…”

“…However, 100% is reasonable given these studies and uncertainties in flash classification and false alarm rate (FAR). An IC DE of 90% is assumed based on a comparison of ENTLN flash counts with NASA Marshall Fly’s Eye GLM Simulator (FEGS) (Quick et al., 2017) observations during the GOES‐R PLT field campaign (Allen et al., 2021). Recently, Blakeslee et al.…”

“…In this study, the GLM16 DE was initially assumed to equal 75% based on a comparison of GLM16 flash counts with FEGS observations during the GOES‐R PLT field campaign (Allen et al., 2021). A 75% DE is also consistent with that found by Bateman and Mach (2020).…”