Boundary-Layer Meteorology

, Volume 44, Issue 1–2, pp 33–72 | Cite as

Numerical simulations of stratiform boundary-layer clouds on the meso-γ-scale. Part I: The influence of terrain height differences

  • Michael Tjernström
Article
Accepted:

Abstract

A higher order closure mesoscale model is used to study the influence of terrain height differences on the meso-γ-scale on stratiform boundary-layer clouds. The model is hydrostatic, has a terrain-following coordinate system and a sub-grid scale condensation scheme. It also has a radiation parameterisation for shortwave and longwave radiation in order to calculate radiative cooling/heating. The simulations show that the cloud base height variations induced by the terrain can be much larger than motivated by terrain height variations alone. It is also shown how this behavior is dependent on upstream boundary-layer conditions and/or changes in the turbulence field. Other features studied include the wave in the lee of a ridge/hill and the associated lifting of the cloud base. The results are compared with some simpler physical models, and limitations in those models are demonstrated.

Keywords

Longwave Radiation Mesoscale Model Radiation Parameterisation Height Variation Cloud Base 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
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Copyright information

© Kluwer Academic Publishers 1988

Authors and Affiliations

  • Michael Tjernström
    • 1
  1. 1.Department of MeteorologyUppsala UniversityUppsalaSweden

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