Record Details
Influence of stratification and accelerations on boundary production of vertical motion
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Influence of stratification and accelerations on boundary production of vertical motion |
| Names |
Park, Soon-Ung
(creator) Mahrt, Larry J. (advisor) |
| Date Issued | 1978-03-29 (iso8601) |
| Note | Graduation date: 1978 |
| Abstract | The influence of boundary layer pumping on an externally-forced synoptic-scale flow is examined. The results follow earlier theories of stratified incompressible Boussinesq flow. These theories state that the spin-down time scale and the penetration depth of the influence of boundary layer pumping are inversely proportional to the stratification and directly proportional to the horizontal length scale of the flow. However, the present development is performed in isentropic coordinates which allow estimates applicable to the atmosphere, and implicitly includes nonlinear influences due to tilting and vertical advection. This analysis indicates that boundary layer pumping could be important synoptically in the lower troposphere under conditions of significant surface stress and tropospheric stratification. The influence of stratification and accelerations on synoptic-scale, boundary layer production of vertical motion is examined for the case of oscillating boundary-layer flow driven by time-dependent, horizontally- periodic surface temperature perturbations. It is found that only very strong stratification can significantly reduce the boundary layer pumping through pressure adjustments within the boundary layer. As a step in understanding the complicated dynamics of the structure of accelerated stratified boundary layers, order-of-magnitude analyses of variables for each layer are examined. This structure depends on the relative magnitude of the non-dimensional forcing frequency and the product of the stratification parameter and Ekman number. Applications to both synoptic and diurnal atmospheric circulations are considered. |
| Genre | Thesis/Dissertation |
| Topic | Planetary boundary layer |
| Identifier | http://hdl.handle.net/1957/28910 |
