Quantifying the tropospheric ozone radiative effect and its temporal evolution in the satellite era

Abstract

Using state-of-the-art satellite ozone profile products, and a chemical transport model, we provide an updated estimate of the tropospheric ozone radiative effect (TO3RE) and observational constraint on its variability over the decade 2008-2017. Previous studies have shown the short-term (i.e. a few years) globally weighted average TO3RE to be 1.17 ± 0.03 W m-2. However, from our analysis, using decadal (2008-2017) ozone profile datasets from the Infrared Atmospheric Sounding Interferometer, average TO3RE ranges between 1.21 and 1.26 W m-2. Over this decade, the modelled and observational TO3RE linear trends show a negligible change (e.g. ± 0.1 % yr-1). Two model sensitivity experiments fixing emissions and meteorology to 1 year (i.e. start year - 2008) show that temporal changes in ozone precursor emissions (increasing contribution) and meteorological factors (decreasing contribution) have counteracting tendencies, leading to a negligible globally weighted average TO3RE trend.