AMS 22nd Conference on the Middle Atmosphere

New studies reveal that stratospheric ozone’s response to increased CO2 mitigates the subsequent acceleration of the Brewer-Dobson Circulation (BDC). Although present in several modeling frameworks, the physical mechanisms for this result remain unclear. Further, it is not yet known how the interactive ozone impact compares in magnitude to the direct radiative CO2 forcing or surface warming. In this study, we design idealized simulations with the NASA Goddard Institute for Space Studies (GISS) E2.2 model in both a fully coupled and atmosphere-only configuration. The atmosphere-only configuration is used to decompose the full atmospheric response to CO2 into three components: the direct CO2 response, the response to sea surface temperature changes, and the response to the interactive ozone. This decomposition reveals that the ozone impact on the BDC strength is as large as the direct CO2 radiative response. The relevant processes connecting these ozone changes to the response of the stratospheric circulation are discussed.