ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-5-1557-2005 Chemistry-climate model SOCOL: a validation of the present-day climatology Egorova T. 1 2 Rozanov E. 1 2 Zubov V. 3 Manzini E. 4 Schmutz W. 2 Peter T. 1 Institute for Atmospheric and Climate Science ETH, Zurich, Switzerland Physical-Meteorological Observatory/World Radiation Center, Davos, Switzerland Main Geophysical Observatory, St.-Petersburg, Russia National Institute for Geophysics and Volcanology, Bologna, Italy 21 06 2005 5 6 1557 1576 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/5/1557/2005/acp-5-1557-2005.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/5/1557/2005/acp-5-1557-2005.pdf

In this paper we document "SOCOL", a new chemistry-climate model, which has been ported for regular PCs and shows good wall-clock performance. An extensive validation of the model results against present-day climate data obtained from observations and assimilation data sets shows that the model describes the climatological state of the atmosphere for the late 1990s with reasonable accuracy. The model has a significant temperature bias only in the upper stratosphere and near the tropopause at high latitudes. The latter is the result of the rather low vertical resolution of the model near the tropopause. The former can be attributed to a crude representation of radiation heating in the middle atmosphere. A comparison of the simulated and observed link between the tropical stratospheric structure and the strength of the polar vortex shows that in general, both observations and simulations reveal a higher temperature and ozone mixing ratio in the lower tropical stratosphere for the case with stronger Polar night jet (PNJ) and slower Brewer-Dobson circulation as predicted by theoretical studies.