The Copernicus Sentinel-6 Michael Freilich satellite delivers promising first altimeter data
First images from ocean-monitoring satellite released.
The first data from the European-US ocean-monitoring satellite Copernicus Sentinel-6 Michael Freilich, launched on 21 November, show the spacecraft’s altimeter is on track to provide highly accurate measurements of sea level, sea state and ocean surface wind speed.
10, December 2020
Sea level products extracted from the first 19 hours’ worth of altimeter data received on 4 December, overlaid on a map showing the similar products from all of the Copernicus altimetry missions – Jason-3, Sentinel-3A and -3B - confirm Copernicus Sentinel-6 Michael Freilich is “seeing the same scene” in a dynamic area of the ocean south of South Africa.
The products reflect highs and lows in the ocean surface topography that, like high and low pressure in the atmosphere, regulate ocean currents. (Link to image)
The products are retrieved from basic radar altimeter measurements, called “waveforms”. The shape of those waveforms not only allows the height of the sea surface to be determined, but also the height of ocean waves and the wind speed at the ocean surface. The novelty of the Sentinel-6 altimeter is that it produces simultaneously low resolution and high resolution waveforms along the satellite ground track. The low resolution is the same as Jason-3 (a few km), allowing for the continuation and the preservation of the integrity of the unique sea level climate record started in 1992 with TOPEX/Poseidon, while the high resolution of 330 m can resolve small but energetic ocean eddies in the open ocean and sea level variations close to the coast. (Link to image)
EUMETSAT Director-General Alain Ratier presented the first products on behalf of the Sentinel-6 mission partners at a special event at EU Space Week, held virtually this year, two days before the fifth anniversary of the signing of the Paris Agreement.
“These first altimeter measurements are not only a promise to the user community but also the first reward of a fantastic European and transatlantic cooperation,” Ratier said. “Now our engineers and scientists will work hard to combine data from all payload instruments and tune ground processing to release a first set of validated low-resolution products in six months from now, and the full set, including high-resolution and climate quality products, at the end of 2021.”
The first set of products released next June will provide critical inputs for operational ocean forecasts delivered by the Copernicus Marine Environment Monitoring Service, and will improve our understanding of how human activities affect the health of the global ocean. They will also feed weather and seasonal forecasts produced by the ECMWF and the national meteorological services in EUMETSAT’s Member States and worldwide.
The Sentinel-6 climate quality products will improve our understanding of climate change in the context of the Paris Agreement and support adaptation policies in coastal areas and by small island States threatened by sea level rise.
The Copernicus Sentinel-6 programme partners are the European Commission, the European Space Agency, EUMETSAT, NASA and the US National Oceanic and Atmospheric Administration.