Articles | Volume 15, issue 9
Ann. Geophys., 15, 1123–1141, 1997

Special issue: Wind Measurements

Ann. Geophys., 15, 1123–1141, 1997

  30 Sep 1997

30 Sep 1997

An intercomparison between the GSWM, UARS, and ground based radar observations: a case-study in January 1993

S. E. Palo1, M. E. Hagan1, C. E. Meek2, R. A. Vincent3, M. D. Burrage4, C. McLandress5, S. J. Franke6, W. E. Ward5, R. R. Clark7, P. Hoffmann8, R. Johnson4, D. Kürschner9, A. H. Manson2, D. Murphy10, T. Nakamura11, Y. I. Portnyagin12, J. E. Salah13, R. Schminder9, W. Singer8, T. Tsuda11, T. S. Virdi14, and Q. Zhou15 S. E. Palo et al.
  • 1National Center for Atmospheric Research, Boulder, CO, USA
  • 2University of Saskatchewan, Saskatoon, Canada
  • 3University of Adelaide, Adelaide, Australia
  • 4University of Michigan, Ann Arbor, MI, USA
  • 5York University, Toronto, Canada
  • 6University of Illinois, Urbana, IL, USA
  • 7University of New Hampshire, Durham, NH, USA
  • 8Institut für Atmosphärenphysik, Kühlungsborn, Germany
  • 9Leipzig University, Collm, Germany
  • 10Australian Antarctic Division, Kingston, Australia
  • 11Kyoto University, Kyoto, Japan
  • 12Institute of Experimental Meteorology, Obninsk, Russia
  • 13Massachusetts Institute of Technology, Westford, MA, USA
  • 14The University College of Wales, Aberystwyth, UK
  • 15Arecibo Observatory, Arecibo, Puerto Ricoyth, UK

Abstract. 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.

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