Global impact of lightning-produced oxidants

Lightning plays a major role in tropospheric oxidation, and its role on
modulating tropospheric chemistry was thought to be emissions of nitrogen
oxides (NOx). Recent field and laboratory measurements demonstrate that
lightning generates extremely large amounts of oxidants, including
hydrogen oxides (HOx) and O3. We here implement the lightning-produced
oxidants in a global chemical transport model to examine its global impact
on tropospheric composition. We find that lightning-produced oxidants can
increase global mass weighted OH by 0.3-10%, and affect CO, O3, and
reactive nitrogen substantially, depending on the emission strength of
oxidants from lightning. Our work highlights the importance and
uncertainties of lightning-produced oxidants, as well as the need for
rethinking the role of lightning in tropospheric oxidation chemistry.