Solar cycle variations of stratospheric ozone and temperature in simulations of a coupled chemistry-climate model J. Austin1, L. L. Hood2, and B. E. Soukharev2 1NOAA Geophysical Fluid dynamics Laboratory, PO Box 308, Princeton, NJ 08542-0308, USA 2Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA
Abstract. The results from three 45-year simulations of a coupled chemistry climate model
are analysed for solar cycle influences on ozone and temperature. The
simulations include UV forcing at the top of the atmosphere, which includes a
generic 27-day solar rotation effect as well as the observed monthly values of
the solar fluxes. The results are analysed for the 27-day and 11-year
cycles in temperature and ozone. In accordance with previous results, the
27-day cycle results are in good qualitative agreement with observations,
particularly for ozone. However, the results show significant variations,
typically a factor of two or more in sensitivity to solar flux, depending on
the solar cycle.
In the lower and middle stratosphere we show good agreement also between the
modelled and observed 11-year cycle results for the ozone vertical profile
averaged over low latitudes. In particular, the minimum in solar response near
20 hPa is well simulated. In comparison, experiments of the model with fixed
solar phase (solar maximum/solar mean) and climatological sea surface
temperatures lead to a poorer simulation of the solar response in the
ozone vertical profile, indicating the need for variable phase
simulations in solar sensitivity experiments. The role of sea surface
temperatures and tropical upwelling in simulating the ozone minimum response
are also discussed.
Citation: Austin, J., Hood, L. L., and Soukharev, B. E.: Solar cycle variations of stratospheric ozone and temperature in simulations of a coupled chemistry-climate model, Atmos. Chem. Phys., 7, 1693-1706, doi:10.5194/acp-7-1693-2007, 2007.