Mobile version

Rapid-changing ocean circulation seen thanks to the 1-day orbit

Swot sea level anomalies for April 2023 over the Gulf Stream, mapped from 250-m data. The satellite was on its 1-day calval orbit, thus showing rapid-changing ocean circulation patterns. (Credits Cnes/CLS/JPL)

Ocean circulation was once thought to be a collection of rather stable ocean currents. The first altimeters showed the ubiquitous variability of the ocean at the 200-300 km scale, with all its meanders and eddies, and allowed a new era to begin, including the prediction of this variability. Swot (Nasa/Cnes) sees more and faster-changing details. During the first six months of the mission, Swot was placed in an orbit that passed over the same point every day. Over a point where two tracks crossed, that meant twice a day. The goal was to validate the measurements, but it had the added benefit of observing rapidly changing features of the oceans. Above is an example in an energetic area, the Gulf Stream (east of the US East Coast) with a map every 12 hours over a full month (April 2023) with a resolution of 250 m (full resolution).

The animation shows the topography as observed by the KaRIn instrument. We can see a large eddy that stays long (the cold one in the upper left at the beginning of the animation, which stays almost all the time), eddies traveling and crossing both tracks, and very fast changes in the circulation with small eddies splitting and merging.

The successive maps are extremely consistent without post-processing. However, some days show artifacts from rain, noise from high waves, etc. The data used for this animation is not yet calibrated, so some tracks show a bias.

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!