Quantifying the Effects of Stratosphere–Troposphere Exchange on Tropospheric Ozone Radiative Forcing

In this study, we calculate ozone radiative forcings using an offline radiative transfer model (RTM) with two different ozone fields: the stratospheric ozone tracer (StratO₃) and O₃simulated from the high-resolution GEOS-5 Replay run (~50 km). The StratO₃is used to quantify O₃of stratospheric origin in the troposphere at all locations and times. The offline module is set up so that all input fields except ozone remain fixed. Therefore, the ozone radiative forcing of these two runs of the radiation code and their difference help us quantify the radiative forcing variations due to the changes in tropospheric ozone with stratospheric origin, and their importance relative to radiative forcing from total ozone. Our study focuses on regions like the tropical southeastern Pacific, where the changes of ozone radiative forcing are highly influenced by the changes in STE.