Dynamical components of northern hemispheric zonal mean total ozone changes during 1979-93

[1] In this work, we examine the influence of northern hemispheric large-scale eddy fluxes on the zonal mean total ozone changes. For this purpose, zonal means of the eddy fluxes of the period 1979-93 were introduced into a dynamically-chemically coupled two-dimensional circulation model, based on a diffusivity approach for the quasi-geostrophic potential vorticity, the potential temperature and the chemical tracers. The model calculations show that the eddy fluxes induce regular interannual ozone variations with a period of about 3-3.5 years in the northern midlatitudes, and, for the pre-Pinatubo time period 1979-91, a decadal decline in the northern hemispheric total ozone that amounts to about 50% of the observed trend.