Tropospheric circulation sensitivity to an interactive stratospheric ozone

Abstract

For this conceptual study we focus on the impact of interactive stratospheric ozone chemistry on the tropospheric circulation, using the atmosphere-ocean-sea ice general circulation model (AOGCM) ECHO-GiSP with simplified stratospheric chemistry. The model covers the troposphere and middle atmosphere up to 80 km height. Our results show a clear sensitivity of the tropospheric circulation dynamics to the stratospheric chemistry. With enabled interactive stratospheric chemistry the model tends to the negative phase of the Arctic Oscillation (AO) mode. This also includes an enhanced midlatitudinal planetary and synoptic scale wave activity. The strengthening of the synoptic scale waves leads to stronger stormtracks, while the planetary scale waves show larger changes outside this particular latitudes. Another tropospheric region, which is influenced by interactive stratospheric chemistry effects, is the tropical troposphere. Due to changes in lower stratospheric ozone concentrations a significant cooling appears in the positive AO-phase compared to the negative phase. Copyright 2008 by the American Geophysical Union.