Mobile version

A turbulent sea

Image of the Month - May 1999


Dynamic sea surface heights forecast at 125 meters for 10/28/93 (from Soap model) and buoys tracked around the Azores (lines show Surdrift and Bodega buoy tracks over three days, squares show where they were released). The figure reveals how the buoys drift with the ocean currents, which circulate in a clockwise (anticyclonic) direction around the hills (in mauve) and in a counter-clockwise direction (in green) around the valleys.See animation (472 Kb).



A cyclonic eddy off the coasts of Labrador. This eddy, branched of the Labrador Current can be seen due to the sea ice it carries.
(Credits E. Dombrowsky)

Ocean currents are sometimes compared to "sea highways", because ships follow their flow to gain speed. But this picture is not wholly accurate. In fact, ocean currents are more like secondary roads branching off into narrow country roads and lanes, winding their way around the hills and natural obstacles. For example, the main flow of these currents is often perturbed by eddies that form at their edge. These swirling eddies can often be as much as 300 kilometers across. The same kind of phenomenon is seen in rivers where the flow encounters an obstruction, such as a bridge for example, where eddies form downstream of the piers. In the same way, water eddies around the hills and valleys of the ocean surface. So the ocean is really more like a vast, slowly swirling whirlpool bath than a swimming pool divided into perfectly straight lanes.

Modern oceanography is concerned with forecasting ocean currents and their meanders and eddies. The Soap model and its successor Soprane, developed at Shom, the French Navy's hydrography and oceanography department, are the first steps on the road to truly global ocean forecasting.

See also:

Websites on this subject:

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!