 |
| Titel |
On the spectral distribution of kinetic energy in large-scale atmospheric flow |
| VerfasserIn |
A. Wiin-Nielsen |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1023-5809
|
| Digitales Dokument |
URL |
| Erschienen |
In: Nonlinear Processes in Geophysics ; 5, no. 3 ; Nr. 5, no. 3, S.187-192 |
| Datensatznummer |
250002479
|
| Publikation (Nr.) |
 copernicus.org/npg-5-187-1998.pdf |
|
|
|
|
|
| Zusammenfassung |
| A one-dimensional form of the equation of
motion with forcing and dissipation is formulated in the spectral domain and used to make
long term integrations from which the spectral distribution of the kinetic energy is
determined The forcing in the wave number domain is determined in advance and kept
constant for the duration of the time integrations. The dissipation is proportional to the
second derivative of the velocity. The applied equation is made non-dimensional by selecting a length
scale from which the time scale and the velocity scale may be determined. The resulting
equation contains no parameters apart from the forcing. The integrations use a large
number of spectral components and no approximation is made with respect to the non-linear
interaction among the spectral components. Starting from an initial state in which all the
velocity components are set to zero the equation is integrated for a long time to see if
it reaches a steady state. The spectral distribution of the kinetic energy is determined in the
steady state, and it is found that the distribution, in agreement with observational
studies, may be approximated by a power law of the form n-3 within certain wave
number regions. The wave numbers for which the -3 power law applies is found between the
region of maximum forcing and the dissipation range. The intensity of the maximum forcing is varied to see how the resulting
steady state varies. In addition, the maximum number of spectral components is varied.
However, the available computing power sets an upper limit to the number of components. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|