Modelling the impacts of climate change on tropospheric ozone over three centuries G. B. Hedegaard1,2, A. Gross1, J. H. Christensen1, W. May2, H. Skov1,3, C. Geels1, K. M. Hansen1, and J. Brandt1 1National Environmental Research Center, Aarhus University, Roskilde, Denmark 2Danish Climate Center, Danish Meteorological Institute, Copenhagen, Denmark 3University of Southern Denmark, Inst. of Chemical Engineering, Biotechnology and Environmental Technology, Odense, Denmark
Received: 21 Dec 2010 – Accepted: 11 Feb 2011 – Published: 25 Feb 2011
Abstract. The ozone chemistry over three centuries has been simulated based on climate
prediction from a global climate model and constant anthropogenic emissions
in order to separate out the effects on air pollution from climate change.
Four decades in different centuries has been simulated using the chemistry
version of the atmospheric long-range transport model; the Danish Eulerian
Hemispheric Model (DEHM) forced with meteorology predicted by the
ECHAM5/MPI-OM coupled Atmosphere-Ocean General Circulation Model. The
largest changes in both meteorology, ozone and its precursors is found in
the 21st century, however, also significant changes are found in the
22nd century. At surface level the ozone concentration is predicted to
increase due to climate change in the areas where substantial amounts of
ozone precursors are emitted. Elsewhere a significant decrease is predicted
at the surface. In the free troposphere a general increase is found in the
entire Northern Hemisphere except in the tropics, where the ozone
concentration is decreasing. In the Arctic the ozone concentration will
increase in the entire air column, which most likely is due to changes in
transport. The change in temperature, humidity and the naturally emitted
Volatile Organic Compounds (VOCs) are governing with respect to changes in
ozone both in the past, present and future century.
Citation: Hedegaard, G. B., Gross, A., Christensen, J. H., May, W., Skov, H., Geels, C., Hansen, K. M., and Brandt, J.: Modelling the impacts of climate change on tropospheric ozone over three centuries, Atmos. Chem. Phys. Discuss., 11, 6805-6843, doi:10.5194/acpd-11-6805-2011, 2011.