A NOTE ON THE APPLICATION OF LINEAR WAVE THEORY AT A CRITICAL LEVEL
Authors: Dörnbrack A.1; Nappo C.J.2
Source: Boundary-Layer Meteorology, Volume 82, Number 3, 1997 , pp. 399-416(18)
Publisher: Springer
- Free Content
- New Content
- Subscribed Content
- Free Trial Content
Abstract:
The purpose of this note is to estimate the accuracy and practical limitations of applying linear theory at a critical level over a realistic range of atmospheric stabilities for an idealized surface terrain. These estimates are made by comparing the results of a linear model with a nonlinear numerical model at a critical level. Essentially similar results are obtained from each model for wave stress, wave breaking height and wave dissipation through the critical level. Because gravity waves can be either evanescent or internal depending on the relative sizes of the Scorer parameter and the wavenumber of the ground surface disturbance, the somewhat paradoxical result develops that wave breaking and non-linearity increase with increasing bulk Richardson number. It is recommended that steady linear wave theory be used in gravity wave drag parameterizations provided near real time profiles of background velocity and temperature are available.
Keywords: Stratified flows; Critical Level; Linear Wave Theory; Numerical Simulations
Language: English
Document Type: Regular paper
Affiliations: 1: DLR, Institut für Physik der Atmosphäre, D – 82230 Oberpfaffenhofen, Germany 2: Atmospheric Turbulence and Diffusion Division Air Resources Laboratory/NOAA, 456 S. Illinois Ave, Oak Ridge, TN 37831, USA
- Free Content
- New Content
- Subscribed Content
- Free Trial Content
Click here for Page Help