title: Revisiting the hemispheric asymmetry in midlatitude ozone changes following the Mount Pinatubo eruption: A 3-D model study.
abstract: Following the eruption of Mount Pinatubo, satellite and in situ measurements showed a large enhancement in stratospheric aerosol in both hemispheres, but significant midlatitude column O3depletion was observed only in the north. We use a three-dimensional chemical transport model to determine the mechanisms behind this hemispheric asymmetry. The model, forced by European Centre for Medium-Range Weather Forecasts ERA-Interim reanalyses and updated aerosol surface area density, successfully simulates observed large column NO2decreases and the different extents of ozone depletion in the two hemispheres. The chemical ozone loss is similar in the Northern (NH) and Southern Hemispheres (SH), but the contrasting role of dynamics increases the depletion in the NH and decreases it in the SH. The relevant SH dynamics are not captured as well by earlier ERA-40 reanalyses. Overall, the smaller SH column O3depletion can be attributed to dynamical variability and smaller SH background lower stratosphere O3concentrations.
authors.affiliation: School of Earth and Environment University of Leeds Leeds UK; National Centre for Earth Observation University of Leeds Leeds UK.
authors.forename: S S
authors.initials: SS
authors.lastname: Dhomse
authors.affiliation: School of Earth and Environment University of Leeds Leeds UK; National Centre for Earth Observation University of Leeds Leeds UK.
authors.forename: M P
authors.initials: MP
authors.lastname: Chipperfield
authors.affiliation: School of Earth and Environment University of Leeds Leeds UK; National Centre for Atmospheric Science University of Leeds Leeds UK.
authors.forename: W
authors.initials: W
authors.lastname: Feng
authors.affiliation: School of Earth and Environment University of Leeds Leeds UK.
authors.forename: R
authors.initials: R
authors.lastname: Hossaini
authors.affiliation: School of Earth and Environment University of Leeds Leeds UK; National Centre for Atmospheric Science University of Leeds Leeds UK.
authors.forename: G W
authors.initials: GW
authors.lastname: Mann
authors.affiliation: Jet Propulsion Laboratory California Institute of Technology Pasadena California USA.
authors.forename: M L
authors.initials: ML
authors.lastname: Santee
keywords: Pinatubo; chemical modeling; ozone; satellite data