ANGEO Annales Geophysicae ANGEO Ann. Geophys. 1432-0576 Springer Verlag Göttingen, Germany 10.1007/s00585-997-1123-x An intercomparison between the GSWM, UARS, and ground based radar observations: a case-study in January 1993 Palo S. E. 1 Hagan M. E. 1 Meek C. E. 2 Vincent R. A. 3 Burrage M. D. 4 McLandress C. 5 Franke S. J. 6 Ward W. E. 5 Clark R. R. 7 Hoffmann P. 8 Johnson R. 4 Kürschner D. 9 Manson A. H. 2 Murphy D. 10 Nakamura T. 11 Portnyagin Y. I. 12 Salah J. E. 13 Schminder R. 9 Singer W. 8 Tsuda T. 11 Virdi T. S. 14 Zhou Q. 15 National Center for Atmospheric Research, Boulder, CO, USA University of Saskatchewan, Saskatoon, Canada University of Adelaide, Adelaide, Australia University of Michigan, Ann Arbor, MI, USA York University, Toronto, Canada University of Illinois, Urbana, IL, USA University of New Hampshire, Durham, NH, USA Institut für Atmosphärenphysik, Kühlungsborn, Germany Leipzig University, Collm, Germany Australian Antarctic Division, Kingston, Australia Kyoto University, Kyoto, Japan Institute of Experimental Meteorology, Obninsk, Russia Massachusetts Institute of Technology, Westford, MA, USA The University College of Wales, Aberystwyth, UK Arecibo Observatory, Arecibo, Puerto Ricoyth, UK 30 09 1997 15 9 1123 1141 Copyright: © 1997 S. E. Palo et al. 1997 © European Geosciences Union 1997 This article is available from https://angeo.copernicus.org/articles/15/1123/1997/angeo-15-1123-1997.html The full text article is available as a PDF file from https://angeo.copernicus.org/articles/15/1123/1997/angeo-15-1123-1997.pdf

The Global-Scale Wave Model (GSWM) is a steady-state two-dimensional linearized model capable of simulating the solar tides and planetary waves. In an effort to understand the capabilities and limitations of the GSWM throughout the upper mesosphere and thermosphere a comparative analysis with observational data is presented. A majority of the observational data used in this study was collected during the World Day campaign which ran from 20 January to 30 January 1993. During this campaign data from 18 ground-based observational sites across the globe and two instruments located on the UARS spacecraft were analyzed. Comparisons of these data with the simulations from the GSWM indicate that the GSWM results are in reasonable agreement with the observations. However, there are a number of cases where the agreement is not particularly good. One such instance is for the semidiurnal tide in the northern hemisphere, where the GSWM estimates may exceed observations by 50% . Through a number of numerical simulations, it appears that this discrepancy may be due to the eddy diffusivity profiles used by the GSWM. Other differences relating to the diurnal tide and the quasi-two-day wave are presented and discussed. Additionally, a discussion on the biases and aliasing difficulties which may arise in the observational data is also presented.