A satellite recently launched by NASA and the European Space Agency (ESA) has sent back its first data on sea levels, beginning a new era of more accurate measurements of sea level rise — a key indicator of climate change.
The Sentinel-6 Michael Freilich satellite was launched in late November, carried into orbit by a SpaceX Falcon 9 rocket. It was initially placed into a lower orbit, 11.4 miles below its eventual operational orbit of 830 miles above the Earth’s surface. With its instruments powered on and collecting data, it will now move alongside another satellite, the Jason-3 sea-level satellite launched in 2016, for a period of six to twelve months.
Researchers will compare readings from both the satellites to ensure the accuracy of the new satellite and to precisely calibrate its instruments. Then the new Sentinel-6 will take over as the primary tool for measuring sea-level rise.
“Data from Sentinel-6 Michael Freilich will help us evaluate how the Earth is changing,” Karen St. Germain, director of NASA’s Earth Science Division, said in a statement. “When we combine the data from instruments like the altimeter on Sentinel-6 Michael Freilich with data from other satellites like GRACE-FO and ICESat-2, we can tell how much of the sea level rise is due to melting ice and how much is due to expansion as the oceans warm. Understanding these underlying physical mechanisms is what allows NASA to improve projections of future sea level rise.”
The data collected by Sentinel-6 shows an area of the ocean off the southern tip of Africa, which has been compared with data from three other satellites to ensure its accuracy. The engineers who worked on the new satellite say they are delighted that it is working so smoothly and that the data looks good so far.
“Christmas came early this year,” said Josh Willis, project scientist at NASA’s Jet Propulsion Laboratory in Southern California. “And right out of the box, the data look fantastic.”
