Satellite altimeters are essential components of a global ocean observation system. They provide co-located measurements of significant wave height, wind speed and sea surface topography.

Sea Level Heights

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 and 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, as well as 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. Examples include: sustainable management of ocean resources, fish farming; monitoring of fishing vessel and merchant shipping fleets; safety of people and property at sea; environmental protection; harbour management; sizing of port and maritime structures; monitoring and management of coastal resources and environments; mineral extraction; and tourism.
	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 6 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.

Climate
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.