“…The inclusion of lightning NO x in the free troposphere can substantially contribute to the NO 2 vertical profile and AMF, and thus satellite retrievals (Allen et al, 2021;Pickering et al, 2016;Zhu et al, 2019). Currently, there is a range of an order of magnitude in the lightning NO x emissions reported in the literature (Nault et al, 2017;Schumann & Huntrieser, 2007;Zhu et al, 2019), because of the dependence of lightning NO x on lightning flash rates and potentially other factors like the length of the flash (Pollack et al, 2016) which depend on storm parameters and their uncertainties (Barth et al, 2019). Aircraft measurements along with modeling studies have shown that lightning is the major source of upper tropospheric NO 2 columns over the eastern US (Bertram et al, 2007;Cooper et al, 2006Cooper et al, , 2007Cooper et al, , 2009Lapierre et al, 2020;Nault et al, 2017;Zhu et al, 2019).…”