Mobile version

Cryosat mission's objectives

Cryosat's mission is dedicated to monitoring very precise changes in the elevation and thickness of polar ice sheets and floating sea ice over a three-year period. The observations made by Cryosat will determine whether or not our ice masses are thinning due to global warming.

Cryosphere's role

The cryosphere plays an important role in moderating the global climate. Due to their high albedo, ice masses directly affect the global energy budget by reflecting about 80% of incident sunlight back out to Space. Thus, once formed, ice tends to be maintained. However, if ice cover were to decrease, less solar radiation would be reflected away from the surface of the Earth - causing the ice to absorb more heat and consequently melt faster still (commonly named a positive feedback).

Ice sheets and glaciers are a control on sea level. They are the largest uncertainty factor in determining the source of the present rise in sea level.

Cryosat measurements

Fundamentally, there are two types of polar ice: the ice that floats in the oceans and the ice that lies on land. Not only do these two forms of ice have different consequences for our planet and its climate, they also pose different challenges when trying to measure them from Space.

Floating sea ice

Sea ice is relatively thin - up to a few metres thick, but it influences regional temperature and the circulation of ocean currents, and consequently the Earth's climate. Cryosat will acquire precise measurements of the thickness of floating sea ice so that annual variations can be detected.

Cryosat will determine the thickness of floating sea ice by measuring the freeboard of ice floes; that is the height by which the ice extends above the water's surface. Cryosat will achieve improved spatial resolution of 250 m in the along-track direction using the Synthetic Aperture technique.

Ice-shelf break up

In contrast, the ice sheets that blanket Antarctica and Greenland are several kilometres thick. The growth and shrinkage of these ice masses have a direct influence on sea level. The approach used for measuring these vast thicknesses is to determine the height of the surface accurately enough to detect small changes.

Further information: Cryosat science overview (Esa website)

EnglishFrançais
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!