Article

 

Effects of Inversion Height and Surface Heat Flux on Downslope Windstorms Öffentlichkeit Deposited

Herunterladbarer Inhalt

PDF Herunterladen
https://ir.library.oregonstate.edu/concern/articles/8g84mn582

Descriptions

Attribute NameValues
Creator
Abstract
  • Simulations are presented focusing on the role of temperature inversions in controlling the formation and strength of downslope wind storms. Three mechanisms are examined depending on the relative height of the inversion with respect to the mountain and the stability of vertically propagating mountain waves. For low-level inversions, flows are generated that closely resemble a reduced gravity shallow water hydraulic response with a large vertical displacement of the inversion on the lee side of the mountain. For higher-level inversion cases, simulated flows more closely followed a stratified hydraulic behavior with the inversion acting as a rigid reflective lid. In the third mechanism, downslope winds were forced by a self-induced critical layer located below the inversion height. The presence of the inversion in this case had little effect on the resulting downslope winds. Observations made on the Falkland Islands show that downslope windstorms may preferentially occur in early morning even without synoptic-scale changes in atmospheric structure. Most windstorms on the Falkland Islands generally have a short jet length; rare, longer jet length storms typically occur in conjunction with a strong low-level inversion. Idealized numerical experiments tend to produce a similar response depending on the presence of strong low-level inversion and surface cooling. Results suggest that surface heating can have significant control on the flow response by reducing the low-level inversion strength, or by changing the stratification and wind velocity below the inversion, thereby preventing a strong downslope windstorm.
  • Keywords: Large eddy simulation, Stratified flow, Amplitude mountain waves, Dynamics, Bora, Alpine valley, Layer, Numerical simulations, Rotor, High drag states
Resource Type
DOI
Date Available
Date Issued
Citation
  • Smith, C., & Skyllingstad, E. (2011). Effects of inversion height and surface heat flux on downslope windstorms. Monthly Weather Review, 139(12), 3750-3764. doi: 10.1175/2011MWR3619.1
Journal Title
Journal Volume
  • 139
Journal Issue/Number
  • 12
Urheberrechts-Erklärung
Publisher
Peer Reviewed
Language
Replaces

Beziehungen

Parents:

This work has no parents.

Artikel