Mobile version

Detecting eddies around Antarctica

Image of the Month - July 2023

Polar seas are complex areas for altimetry data, since they are, at least part of the time, covered with ice, which reflects the altimeter radar beam differently than open water. In these regions, sea surface height can however be obtained from radar altimetry in sea ice leads, open water crevices between iced areas. Retrieving sea level information requires specific processing of the altimeter's radar waveforms.
The Southern Ocean around Antarctica is moreover an energetic region, with eddies playing a role in the heat and nutrient transport across the different current fronts. Sea level anomalies gridded datasets encompassing those seasonnally-ice covered regions have been computed and released for Arctic and Antarctic regions. From those, Eddy Kinetic Energy (EKE) and mesoscale eddies detection can be processed.

From these, it appears that  eddies are distributed evenly in the subpolar Southern Ocean, but their amplitude, following the pattern of the Eddy Kinetic Energy is different. Eddies have low amplitude and density in the pack ice, while the northern part of the Marginal Ice Zone is favorable for mesoscale eddies, especially cyclonic. In this region, we expect to see genesis of fronts due to sea ice melt and upwelling generated from interactions between the wind and the sea ice.  It must be mentionned that all of the eddies aren't detected by the method, since eddies are smaller at high latitude, and many fall under detection level. However, the ones detected can give hints on the general interactions in the region. 

Polar regions are very sensitive, and less observed by in situ instruments than lower latitudes. Satellites which do observe them (not all altimetry satellites) are bringing important clues on the iced regions, their dynamics and ultimately their evolution.

See also:


  • Auger, M., Sallée, J.-B., Thompson, A. F., Pauthenet, E. and Prandi, P. (2023). Southern Ocean ice-covered eddy properties from satellite altimetry. Journal of Geophysical Research: Oceans, 128, e2022JC019363.


Rss feedsContactPartnersFAQLexiconLegal noticePersonal Data Protection PolicyMobile
You must enable cookies in your browser preferences to save the modifications
You are using an older version of Internet Explorer, please update to take full advantage of Aviso+ features

Customize the home page

View all widgets
Reduce display
Public profile
User profile

Select/Deselect widgets

Discover AVISO+

Customizable home, reading tools, products search guide, etc.. Discover step by step the features of the new site AVISO+.

Customizable homepage

This home page is composed of blocks called "widgets".

Rearrange the blocks with a "Click & Drop".

Hide a widget with the cross at the top right. Reset or add a widget with the "wrench" icon. The "User" and "Public" profiles offer a predefined organization.

All the modifications are automatically saved as cookies on your machine so as to enable you to have your own specific AVISO+.

Reading tools

Ease your reading by choosing the page background colour (black/white) and/or by modifying the font size.

Browsing menu and breadcrum trail

To ease your browsing through AVISO+, you can use at any time the main banner items with the interactive submenus or use the browsing menu on the left side of the screen (it is open by default). For more readiness of the page contents, you can fold and unfold the browsing menu by clicking on the tab. At any time you can know where you are thanks to the browsing menu or the breadcrum at the top of the page.

Products search guide

The first submenu of the "Data" banner item leads you to a new search form enabling you to find quickier the product that suits your needs. The list of results is updated according to your selection criteria.

AVISO+ Multimedia

The first submenu of the "Multimedia" banner item leads you to AVISO+ collections of images and videos linked to altimetry and its applications. Have a nice visit!