St Andrews Research Repository

St Andrews University Home
View Item 
  •   St Andrews Research Repository
  • University of St Andrews Research
  • University of St Andrews Research
  • University of St Andrews Research
  • View Item
  •   St Andrews Research Repository
  • University of St Andrews Research
  • University of St Andrews Research
  • University of St Andrews Research
  • View Item
  •   St Andrews Research Repository
  • University of St Andrews Research
  • University of St Andrews Research
  • University of St Andrews Research
  • View Item
  • Login
JavaScript is disabled for your browser. Some features of this site may not work without it.

The stability of Mars' annular polar vortex

Thumbnail
View/Open
Seviour_2017_Stability_of_Mars_JAS_1533.pdf (6.780Mb)
Date
05/2017
Author
Seviour, William
Waugh, Darryn
Scott, Richard Kirkness
Keywords
QA Mathematics
QB Astronomy
QC Physics
NDAS
Metadata
Show full item record
Altmetrics Handle Statistics
Altmetrics DOI Statistics
Abstract
The Martian polar atmosphere is known to have a persistent local minimum in potential vorticity (PV) near the winter pole, with a region of high PV encircling it. This finding is surprising since an isolated band of PV is barotropically unstable, a result going back to Rayleigh. Here we investigate the stability of a Mars-like annular vortex using numerical integrations of the rotating shallow water equations. We show how the mode of instability and its growth rate depends upon the latitude and width of the annulus. By introducing thermal relaxation towards an annular equilibrium profile with a time scale similar to that of the instability, we are able to simulate a persistent annular vortex with similar characteristics as that observed in the Martian atmosphere. This time scale, typically 0.5-2 sols, is similar to radiative relaxation time scales for Mars’ polar atmosphere. We also demonstrate that the persistence of an annular vortex is robust to topographic forcing, as long as it is below a certain amplitude. We hence propose that the persistence of this barotropically unstable annular vortex is permitted due to the combination of short radiative relaxation time scales and relatively weak topographic forcing in the Martian polar atmosphere.
Citation
Seviour , W , Waugh , D & Scott , R K 2017 , ' The stability of Mars' annular polar vortex ' , Journal of the Atmospheric Sciences , vol. 74 , no. 5 , pp. 1533-1547 . https://doi.org/10.1175/JAS-D-16-0293.1
Publication
Journal of the Atmospheric Sciences
Status
Peer reviewed
DOI
https://doi.org/10.1175/JAS-D-16-0293.1
ISSN
0022-4928
Type
Journal article
Rights
© 2017, American Meteorological Society. This work has been made available online in accordance with the publisher’s policies. This is the final published version of the work, which was originally published at journals.ametsoc.org / https://doi.org/10.1175/JAS-D-16-0293.1
Description
This research was partially supported by a NASA grant from the Mars Fundamental Research Program (NNX14AG53G).
Collections
  • University of St Andrews Research
URI
http://hdl.handle.net/10023/11541

Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.

Advanced Search

Browse

All of RepositoryCommunities & CollectionsBy Issue DateNamesTitlesSubjectsClassificationTypeFunderThis CollectionBy Issue DateNamesTitlesSubjectsClassificationTypeFunder

My Account

Login

Open Access

To find out how you can benefit from open access to research, see our library web pages and Open Access blog. For open access help contact: openaccess@st-andrews.ac.uk.

Accessibility

Read our Accessibility statement.

How to submit research papers

The full text of research papers can be submitted to the repository via Pure, the University's research information system. For help see our guide: How to deposit in Pure.

Electronic thesis deposit

Help with deposit.

Repository help

For repository help contact: Digital-Repository@st-andrews.ac.uk.

Give Feedback

Cookie policy

This site may use cookies. Please see Terms and Conditions.

Usage statistics

COUNTER-compliant statistics on downloads from the repository are available from the IRUS-UK Service. Contact us for information.

© University of St Andrews Library

University of St Andrews is a charity registered in Scotland, No SC013532.

  • Facebook
  • Twitter