 |
| Titel |
Energetics of the layer-thickness form drag based on an integral identity |
| VerfasserIn |
H. Aiki, T. Yamagata |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1812-0784
|
| Digitales Dokument |
URL |
| Erschienen |
In: Ocean Science ; 2, no. 2 ; Nr. 2, no. 2 (2006-10-12), S.161-171 |
| Datensatznummer |
250000512
|
| Publikation (Nr.) |
 copernicus.org/os-2-161-2006.pdf |
|
|
|
|
|
| Zusammenfassung |
| The vertical redistribution of the geostrophic momentum by the residual
effects of pressure perturbations (called the layer-thickness form drag)
is investigated using thickness-weighted temporal-averaged mean
primitive equations for a continuously stratified fluid in an adiabatic
formulation.
A four-box energy diagram, in which the mean and eddy kinetic energies
are defined by the thickness-weighted mean velocity and the deviation
from it, respectively, shows that the layer-thickness form drag reduces
the mean kinetic energy and endows the eddy field with an energy cascade.
The energy equations are derived using an identity (called the "pile-up
rule") between cumulative sums of the Eulerian mean quantity and the
thickness-weighted mean quantity in each vertical column.
The pile-up rule shows that the thickness-weighted mean velocity
satisfies a no-normal-flow boundary condition at the top and bottom of
the ocean, which enables the volume budget of pressure flux divergence
in the energy diagram to be determined.
With the pile-up rule, the total kinetic energy based on the Eulerian
mean can be rewritten in a thickness-weighted form.
The four-box energy diagram in the present study should be consistent
with energy diagrams of layer models, the temporal-residual-mean
theory, and Iwasaki's atmospheric theory.
Under certain assumptions, the work of the layer-thickness form drag in the
global ocean circulation is suggested to be comparable to the work done
by the wind forcing. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|