Satellite altimeters as carried on Jason-2 are essential components of a global ocean observation system, providing co-located measurements of significant wave height, wind speed and sea surface topography. The Jason-2 programme links two operational and two research agencies (EUMETSAT, NOAA, CNES and NASA) and also brings about a transition from a research phase towards operational applications.
Jason-3 is currently scheduled for launch in 2014.
Altimetric data from Jason-2 have also helped create detailed decade-long global observations and analyses of the El Niño and La Niña phenomena, opening the way to new discoveries about ocean circulation and its effects on climate, and providing new insights into ocean tides, turbulent ocean eddies and marine gravity.
One of the major objectives of the Jason-2 Ocean Surface Topography Mission is to support operational oceanography. Nearly 71% of the Earth's surface is covered by oceans, two-thirds of the world's population live within 60 kilometres of the coast, and half of the world's cities, with more than one million people, are situated around river mouths. Oceans are a major source of food and employment, but can also pose a threat to lives and values, so operational forecasts of the ocean 'weather' are of critical importance.
Information on the sea surface height enables the study of the growth and evolution of surface waves, in response to winds and tidal forcing, and one can derive the positions and intensities of ocean currents, eddies and thermal fronts.
Satellite altimetry observations are assimilated by global ocean circulation, sea state and coupled numerical models, and are used to support a variety of applications, including marine meteorology; hurricane forecasting and tracking; fisheries management and ship routing, and climate research and forecasting.
Operational oceanography and its applications
Operational activities can be divided into two categories depending on the time-scale: the short-range ocean forecast (in which we can include coastal aspects) and the seasonal ocean forecast.
Short-range ocean forecasts
Short range ocean forecasts are useful in a variety of applications:
Seasonal ocean forecasting
Seasonal ocean forecasting is one of the most demanding and ambitious objectives. Seasonal forecasting is the attempt to provide useful information about the 'climate' that can be expected in the coming months. Having a precise knowledge of the ocean state is essential to try to forecast what the climate will be like six months ahead. Altimetry is one of the most important tools for monitoring ocean dynamics, and, as such, is a source of vital data for including in seasonal forecasting models to predict ocean-atmosphere coupled events such as El Niño, monsoons or the North Atlantic Oscillation.
The oceans and atmosphere store and exchange energy in the form of heat, moisture, and momentum. The ocean also contributes to carbon storage and oxygen production. Changes in the energy balance between the oceans and atmosphere play an important role in the planet's climate change. From the seasonal to the decadal, or even the centennial timeframe, knowledge about the ocean state and its influence upon the atmosphere is one of the keys to climate forecasting.
The oceans are, in turn, affected by climate variations, as the sea-level rises and falls in response to their fluctuations. Jason-2 will help us to better understand how oceans and climate interact, by continuing to provide long time-series of very precise observations of currents and sea-level. In particular, these data are necessary to enable more accurate detection of anthropogenic (human-caused) influences on the climate.
To learn more about the benefits and applications of OSTM data, you can find a series of short videos in the 'Jason-2 Video Material' section of our Multimedia Gallery.
For more information on the OSTM programme, take a look at our partners' dedicated Jason-2 websites:
Centre National d’Etudes Spatiales (CNES)
The transatlantic Jason-3 Programme was approved in 2010 by EUMETSAT Member States, ensuring a continuation of the series of measurements made by the Jason-2 satellite, and its predecessors, in support of meteorology, operational oceanography and, in particular, the monitoring of the sea-level trend, a key indicator of climate change.
Jason-3 is currently scheduled for launch in 2014 and EUMETSAT plans to merge Jason-2 and Jason-3 operations to optimise resources and be more cost-effecctive.
Twenty EUMETSAT Member States have agreed to subscribe to the Jason-3 ocean altimetry satellite programme: Belgium, Croatia, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, the Netherlands, Norway, Portugal, Romania, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Together, these countries are prepared to contribute €63.6 million (at 2009 economic conditions) to the €252-million programme cost of Jason-3.
The Jason-3 programme is led by EUMETSAT and the US National Oceanic and Atmospheric Administration (NOAA). NOAA secured its participation in the Jason-3 programme in 2009 and has given it top priority for securing climate-related measurements. In addition, the Centre National d’Etudes Spatiales (CNES), the French space agency, is making a significant in-kind contribution to the programme and will act at the technical level as the system coordinator. This in-kind contribution includes making available the Jason-3 Proteus satellite platform, its facilities and associated human resources.
The US National Aeronautics and Space Administration (NASA), in conjunction with the three other partners, will support science team activities. The US contribution to Jason-3 includes the satellite launch, provision of instruments and support to operations. As Jason-3 will secure provision of data for key GMES Services, and in particular the GMES Marine Service, the European Commission is planning to fund the operations of the satellite.
The development of the Jason-3 mission, and related Ground Segment, is based on a recurrent Jason satellite and ground system with a similar partnership scheme to Jason-2.
EUMETSAT will, together with NOAA, take the lead on the programme. EUMETSAT will also maintain the operational role already established for the Jason-2 Programme. These include performing operations and level 1 maintenance of the Earth Terminal; processing, disseminating and archiving the near real time products; providingthe user services, and conducting mission operations jointly with NOAA and CNES.
This optional programme was approved in 2010 and its is planned to comtinue until at least 2018, when the Jason Continuity of Service (Jason-CS) should take over.