Climate Dynamics

, Volume 28, Issue 6, pp 581–597

Parameterisation of orographic cloud dynamics in a GCM

  • S. M. Dean
  • J. Flowerdew
  • B. N. Lawrence
  • S. D. Eckermann
Article

DOI: 10.1007/s00382-006-0202-0

Cite this article as:
Dean, S.M., Flowerdew, J., Lawrence, B.N. et al. Clim Dyn (2007) 28: 581. doi:10.1007/s00382-006-0202-0

Abstract

A new parameterisation is described that predicts the temperature perturbations due to sub-grid scale orographic gravity waves in the atmosphere of the 19 level HadAM3 version of the United Kingdom Met Office Unified Model. The explicit calculation of the wave phase allows the sign of the temperature perturbation to be predicted. The scheme is used to create orographic clouds, including cirrus, that were previously absent in model simulations. A novel approach to the validation of this parameterisation makes use of both satellite observations of a case study, and a simulation in which the Unified Model is nudged towards ERA-40 assimilated winds, temperatures and humidities. It is demonstrated that this approach offers a feasible way of introducing large scale orographic cirrus clouds into GCMs.

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • S. M. Dean
    • 1
  • J. Flowerdew
    • 2
  • B. N. Lawrence
    • 3
  • S. D. Eckermann
    • 4
  1. 1.National Institute of Water and Atmospheric Research LtdWellingtonNew Zealand
  2. 2.Atmospheric Oceanic and Planetary Physics, Clarendon LaboratoryUniversity of OxfordOxfordUK
  3. 3.British Atmospheric Data Centre, Rutherford Appleton LaboratoryChiltonUK
  4. 4.E. O. Hulburt Center for Space Research, Code 7646Naval Research LaboratoryWashington, DCUSA

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