Surface Climate Impacts of Halogen Induced Stratospheric Ozone Changes

PD Dr. Björn-Martin Sinnhuber, PD Dr. Michael Höpfner
Karlsruhe Institute of Technology
Institute of Meteorology and Climate Research
Hermann-von-Helmholz-Platz 1
76344 Eggenstein-Leopoldshafen

Prof. Dr. Klaus Pfeilsticker
Institut für Umweltphysik, Universität Heidelberg

Dr. Jens-Uwe Grooß and Dr. Bärbel Vogel
Forschungszentrum Jülich, Institut für Energie- und Klimaforschung – Stratosphäre

Prof. Dr. Andreas Engel
Institut für Atmosphäre und Umwelt, Goethe Universität Frankfurt

Project Description

The project SCI-HI aims to improve our understanding of the surface climate impacts of halogen induced stratospheric ozone depletion and recovery. Current model projections of the climate impact of stratospheric ozone recovery are still uncertain, because of large uncertainties in modelled ozone changes in the upper troposphere and lower stratosphere (UTLS) region. Short-lived halogen compounds of natural and anthropogenic sources have a particularly large impact on ozone in the UTLS, and a correspondingly large efficiency in affecting climate, but their contribution is still uncertain. Quantifying the climate impact of halogen-induced ozone depletion in the UTLS region under present-day conditions, including the role of short-lived halogens, will provide constraints on the corresponding positive radiative forcing of ozone recovery during the 21st century. Within this project we will

  •  better quantify the contribution of very short-lived substances (VSLS), in the form of organic source gases (VSL SG) and inorganic product gases (VSL PG) to the lower stratospheric halogen loading,
  •  better identify their source regions, transport pathways and times into the UTLS,
  •  investigate the halogen induced ozone depletion in the UTLS region and
  •  calculate improved effective radiative forcing (ERF) and surface climate impacts of these halogen induced ozone changes in the UTLS region.

We will achieve this through a combination of analysing observational data from previous aircraft campaigns, providing additional aircraft observations in the critical but data sparse Southern Hemisphere UTLS region, together with closely coordinated chemistry-transport and chemistry climate model simulations. With improved observational data sets and further model development and applications we will contribute to the further development of the German community Earth System Modelling capabilities.