Mobile version


09.04.2008 12:55 Age: 14 yrs

Altimetry applications in videos : Life in the ocean

Category: Website updates

The ocean is very fertile. By combining biological data with circulation models it is now possible to simulate the complex interactions between ocean physics and chemistry and marine life.

Leatherback turtle path (black line) overlayed on sea level anomalies and geostrophic current, in the Gulf Stream in october 2005. Credits DEPE/IPHC/CNRS and CLS.

See the video Life in the ocean: flash (9 Mo) or mpeg (29 Mo)

The ocean is very fertile - from the surface to the deep abyss plains, the ocean is home to a huge variety of life forms. This marine life is highly constrained by the physical and chemical characteristics of the environment.  The cold waters and available nutrients lead to concentrations of phytoplankton, the first link in the food chain, and currents and drifts create migratory routes. By combining biological data with circulation models it is now possible to simulate the complex interactions between ocean physics and chemistry and marine life.  While satellite measurements of water temperature or chlorophyll content are the most suitable way of quantifying phytoplankton, altimetry measurements of sea surface height are used to complete and confirm the observations.

Areas of intense biological activity have a particular signature that can be observed both in sea height measurements and in chlorophyll content measurements.  Areas with high chlorophyll content are encountered especially around eddies, on the edge of currents, in areas where cold waters well up, or when Rossby waves go by.  Each of these areas can be highlighted and physically characterized by altimetry.

These very productive areas are also a meeting point for other links in the food chain - from zooplankton, through small fish, up to large predators. These more evolved biological levels can be described, analysed and simulated by relating biological and physical data.  Species that are large enough, such as some fish, reptiles and ocean mammals, can be tracked individually with markers (such as Argos transmitters) that are relayed by a network of stations and satellites.  Currents and sea heights, determined from altimetry data, when combined with biotelemetry, have also shown that turtles, during their long migration, move along very specific fronts where their prey accumulates.  This method can be used to understand the behaviour of such animals as well as their migration, reproduction, and feeding strategies, and to set up appropriate protective measures, by limiting their accidental capture in fishing nets.

Sustained stewardship of marine resources, protection of threatened species and understanding the role of climate change on marine life, are major issues.  The Jason-2 altimetry satellite, to be launched in June 2008, will be capable of providing a physical description of the oceans, thus furthering  the development of operational biogeochemical models and increasing our understanding of ecosystems.

Further information :

  • Applications : <link internal-link>Biology
  • External websites :
    • <link http: web external-link-new-window>Argonautica, educational program and <link http: html argonautica welcome_uk.html _blank external-link-new-window>its online data (maps and locations for marine animals),
    • Marine Ecosystem Modeling and Monitoring by Satellite (<link http: memms external-link-new-window>MEMMS),

Rss feedsContactPartnersFAQLexiconMobile
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!