European Facility For Airborne Research

European Facility For Airborne Research May 24, 2018, 08:11

Document

Description
Title Dynamical structures for southwesterly airflow oversouthern Norway: the role of dissipation
Type Publication
Abstract:

Earlier studies have revealed mesoscale structures in southwesterly flows over the mountains of southern Norway (Rossby number ∼1): a left-side jet and an upstream wind minimum as signs of the influence of rotation; a downstream wind shadow connected to inertio-gravity waves; a weak jet on the right side of the wind shadow and a shallow coastal wind shadow between the left-side jet and the main wind shadow. In the present study, the dynamics of the structures have been further examined from the results of experiments performed by a mesoscale numerical model and computations using a linear model with rotation included. Ideal atmospheric conditions for a large-scale wind direction from southwest have been used to initialize the numerical model. The sensitivity of mesoscale structures was studied with respect to dissipation from wave breaking and surface friction. Nonlinearity and dissipation in breaking waves are needed to explain the location, depth and strength of the downstream wind shadow. Increased wind to the right of the shadow was found to be generated by the effect of the Coriolis force as air was pulled towards the low-pressure perturbation behind the mountains. The coastal wind shadow was found to be a direct result of differential friction between land and ocean. Nonlinear experiments and an attempt to include boundary layer effects in linear theory showed that friction is reducing the effective height of the mountain and the signal of the mesoscale structures.

Available from http://onlinelibrary.wiley.com/doi/10.1111/j.1600-0870.2006.00152.x/abstract
Author
BARSTAD Idar
Reference
Journal TELLUS
Volume 58
Pages 2-18
Year 2006
Times cited 0
Institute country Sweden
Type of science
  • Atmospheric dynamics (includes thermodynamics)
Field of science
  • Troposphere
File details
Added Dec. 6, 2006, 00:00
Last update April 19, 2016, 15:22
Size 942.2 KB
File name 14706577264649adaa7852d:BarstadGronas2.pdf
Visibility Public
Links with specific subjects

Go to the document list

Back to top
EUFAR
EU

This project has received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement no. 312609

Copyright © 2018 EUFAR All rights reserved.