# Accession Number:

## ADA244146

# Title:

## Mesoscale Vertical Velocities Generated by Stress Changes in the Boundary Layer: Linear Theory

# Descriptive Note:

# Corporate Author:

## COOPERATIVE INST FOR RESEARCH IN THE ATMOSPHERE FORT COLLINS CO

# Personal Author(s):

# Report Date:

## 1991-07-15

# Pagination or Media Count:

## 18.0

# Abstract:

The mesoscale vertical velocity induced by stress changes in the surface layer is evaluated as a function of the size of the rough patch in relation to environmental parameters. The nature of the flow perturbation strongly depends on the relation between the width of the rough patch and the two natural scales of the flow, i.e. the inverse inertia wave number and the inverse of the Scorer parameter. When the width of the rough patch is comparable to the inverse inertia wave number or larger, the atmospheric perturbation is trapped, the vertical scale equals the depth of the stress surface layer, and the horizontal scale equals the Rossby radius. When the width of the rough patch is larger than the inverse of the Scorer parameter, but smaller than the inverse inertia wave number, the atmospheric perturbation is a hydrostatic gravity wave with a vertical wave number equal to the Scorer parameter. When the width of the rough patch is comparable to the inverse of the Scorer parameter, the atmospheric perturbation is a propagating lee wave with a vertical wave number equal to the Scorer parameter. When the ambient flow is strong over a small rough patch, the flow is irrotational. The same limitations, inherent to the linear gravity waves excited by the forcing in the atmosphere e.g. mountain waves, gravity waves initiated by convection, etc., apply to the mesoscale perturbation induced by a rough patch.

# Descriptors:

# Subject Categories:

- Meteorology