Sentinel-3A improves sea level observation coverage

With its unique track and 27-day revisit cycle, the EU Copernicus Earth Observation Program Sentinel-3A satellite allows covering sea level in locations where it was not or poorly sampled until now.

Since the satellite became operational in April 2017, Sentinel-3A has helped to build daily merged and gridded sea level observations products at the sea surface with unprecedented frequency and accuracy. An example is the data that the mission is providing at the poles and in the tropics. At the poles, Sentinel-3A contributes to 33 to 100% of the total sea level; in the tropics, the satellite accounts for about 20% of the total sea level signal.

The Copernicus Marine Service Sea Level Thematic Assembly Center system, DUACS (Data Unification and Altimeter Combination System) processes sea level data from all available sea level measuring satellites to provide consistent and homogeneous sea level products, both in near real time and in the past. The full potential of Sentinel-3A for sea level products will grow exponentially in the coming years thanks to upcoming research and development activities. The objective is to achieve higher resolution sea level products closer to the coasts.

Sentinel-3 over ocean and ice

Mapping the Earth’s oceans

Covering 70% of the planet, the oceans are intrinsically linked to our weather and climate. They are also essential for global transport and provide a wealth of resources. The surface temperature of the oceans also affects the intensity of hurricanes and tropical cyclones, which cause damage costing hundreds of millions of euros.

Sentinel-3 is a vital tool for closely monitoring changes in surface ocean waters, sea-state, sea-ice thickness and for estimating the heat content of the upper ocean. The mission measures the temperature, colour and height of the sea surface as well as the thickness of sea ice. These measurements will be used, for example, to monitor changes in sea level, marine pollution and biological productivity.

Sea Level products are used in ocean forecast models to keep them close to observations and to provide more accurate forecasts.  Sea Level products are also used by scientists for long-term ocean and climate studies.

While the Copernicus Sentinel-3A satellite is in orbit delivering a wealth of information about our oceans, engineers are putting its twin, Sentinel-3B, through a series of vigorous tests before its launch next year. The satellite is now in the thermal–vacuum chamber in Cannes, France. This huge chamber simulates the huge swings in temperature facing the satellite in space.


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