The atmospheric chemistry general circulation model ECHAM5/MESSy1: consistent simulation of ozone from the surface to the mesosphere P. Jöckel1, H. Tost1, A. Pozzer1, C. Brühl1, J. Buchholz1, L. Ganzeveld1, P. Hoor1, A. Kerkweg1, M. G. Lawrence1, R. Sander1, B. Steil1, G. Stiller2, M. Tanarhte1, D. Taraborrelli1, J. van Aardenne1,*, and J. Lelieveld1 1Max Planck Institute for Chemistry, Atmospheric Chemistry Department, P.O. Box 3060, 55020 Mainz, Germany 2Institute for Meteorology and Climate Research, Forschungszentrum Karlsruhe, P.O. Box 3640, 76021 Karlsruhe, Germany *now at: European Commission, DG Joint Research Centre, Ispra, Italy
Abstract. The new Modular Earth Submodel System (MESSy) describes atmospheric
chemistry and meteorological processes in a modular framework, following
strict coding standards. It has been coupled to the ECHAM5 general
circulation model, which has been slightly modified for this purpose. A
90-layer model setup up to 0.01 hPa was used at spectral T42
resolution to simulate the lower and middle atmosphere.
With the high vertical resolution the model simulates the
meteorology has been tested to check the influence of the changes to ECHAM5
and the radiation interactions with the new representation of atmospheric
composition. In the simulations presented here a Newtonian relaxation
technique was applied in the tropospheric part of the domain to weakly nudge
the model towards the analysed meteorology during the period 1998–2005.
This allows an efficient and direct evaluation with satellite and in-situ
It is shown that the tropospheric wave forcing of the stratosphere in
the model suffices to reproduce major stratospheric warming events
leading e.g. to the vortex split over
Antarctica in 2002. Characteristic features such as dehydration and
denitrification caused by the sedimentation of polar stratospheric cloud
particles and ozone depletion during winter and spring are simulated well,
although ozone loss in the lower polar stratosphere is slightly
underestimated. The model realistically simulates stratosphere-troposphere
exchange processes as indicated by comparisons with satellite and in situ
measurements. The evaluation of tropospheric chemistry presented here
focuses on the distributions of ozone, hydroxyl radicals, carbon monoxide
and reactive nitrogen compounds. In spite of minor shortcomings, mostly
related to the relatively coarse T42 resolution and the neglect of
inter-annual changes in biomass burning emissions, the main characteristics
of the trace gas distributions are generally reproduced well. The MESSy
submodels and the ECHAM5/MESSy1 model output are available through the
internet on request.
Citation: Jöckel, P., Tost, H., Pozzer, A., Brühl, C., Buchholz, J., Ganzeveld, L., Hoor, P., Kerkweg, A., Lawrence, M. G., Sander, R., Steil, B., Stiller, G., Tanarhte, M., Taraborrelli, D., van Aardenne, J., and Lelieveld, J.: The atmospheric chemistry general circulation model ECHAM5/MESSy1: consistent simulation of ozone from the surface to the mesosphere, Atmos. Chem. Phys., 6, 5067-5104, doi:10.5194/acp-6-5067-2006, 2006.