 |
| Titel |
An Investigation into Variable Topography in a Baroclinic Annulus |
| VerfasserIn |
Samuel Marshall, Peter Read |
| Konferenz |
EGU General Assembly 2011
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250046036
|
|
|
|
|
|
| Zusammenfassung |
| For first year of work of this project, a differentially-heated annulus was used to investigate
sloping convection. To this end two studies were made, each motivated by a numerical
investigation that had discovered new phenomena in computational annuli models. The
results of these studies provided a greater understanding of the annulus, allowing
improvement of the experimental arrangement for future work. Subsequent years of this
project will be focussed on the issue of topography, with the theme considered via a review of
the most notable outstanding questions found in the literature. It was decided that the
topographic investigation will examine the viability of less-idealised topography, in particular
by investigating the effect of using a superposition of wavenumbers rather than a simple
sinusoid.
The superposition to be employed was chosen from a Fourier analysis of Martian
topography – at a certain latitude (~40Ë S), wavenumber-1 and wavenumber-3 are dominant.
Utilising the amplitude and phase differences, a superposition of these wavenumbers was
created, to be investigated in comparison to simple wavenumber-3 sinusoid. In this way, a
rough model of the Martian topography can also be studied. It is hoped that this experiment
will provide solutions to the various unresolved questions mentioned previously, such as the
growth-rate and time-scale of the various topographically forced oscillations and
perturbations, the existence of multiple equilibria with less-idealised topography
and the mechanism of generation of Low Frequency Variation (LFV). Thermal
topography, or azimuthally-varying heating, is also up for investigation. By using flat
heating elements on the base of the annulus, the differential-heating caused by the
thermal differences between land and sea in the tropics can be recreated, permitting
simulation of the Walker Circulation. Adaptations to the study of tidally-locked
exoplanets are also possible. Finally, oceanic topography will also be explored via
partial barriers. Partial barriers serve to block part of the flow (either radially or
vertically) and will be employed to study the effects of continental shelves on the ocean
basin.
All of these studies can be interchanged and combined with each other, allowing a large
range of experiments to be proposed (for example, mixing partial barriers and thermal
topography would allow for the study of monsoon conditions). Preliminary results and initial
observations will be available for presentation. |
|
|
|
|
|
|