Changing ozone and changing circulation in northern mid‐latitudes: Possible feedbacks?

Abstract

The Met Office Unified Model including a simplified stratospheric chemistry scheme was used to perform three integrations each of twenty years to study the connection between changes in lower stratospheric ozone and the circulation. The model radiation scheme used 1) the ozone calculated by the model, 2) climatological zonal‐mean ozone derived from 1) and, 3) climatological zonal‐mean ozone with an imposed mid‐latitude ozone loss in the northern hemisphere in spring. Integrations 1) and 2) only differ significantly in the northern hemisphere in January, whereas the spring season is unaffected. The dynamical changes between 1)/2) and 3) are most obvious during March, the time of the strongest imposed loss, but the largest impact, on both dynamics and ozone, is found northwards and upwards from the region of the imposed mid‐latitude anomaly away from middle latitudes. We conclude that in our calculations the imposed (observed) middle latitude loss does not produce a large additional feedback on the ozone distribution.