Parameterisation of Orographic Cloud Dynamics in a GCM

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.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2007
Accession Number
ADA593079

Entities

People

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

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Space

DTIC Thesaurus Topics

  • Artificial Satellites
  • Atmospheres
  • Case Studies
  • Cirrus Clouds
  • Climate Change
  • Clouds
  • Dynamics
  • Gravity
  • Gravity Waves
  • High Resolution
  • Humidity
  • Islands
  • Latent Heat
  • Physics
  • Transition Temperature
  • Two Dimensional
  • Waves

Fields of Study

  • Environmental science

Readers

  • Atmospheric Science/Meteorology
  • Computational Modeling and Simulation
  • Ocean-Atmosphere Mesoscale Modeling, Data Assimilation, and Flux Boundary Layers

Technology Areas

  • Space