We have a new tool for monitoring Earth’s oceans: The Sentinel-6 Michael Freilich spacecraft, which has taken over from its predecessor to become the official satellite for measuring global sea levels. It took over its new role on Tuesday, March 22, and will play an important role in monitoring climate change.

The satellite, which is a joint project between the European Space Agency (ESA) and NASA, was launched in November 2020 and has been collecting initial data since then. Once engineers were confident its instruments were calibrated and accurate, it took over official sea level monitoring from the Jason-3 satellite that was launched in 2016.

“These missions, of which Sentinel-6 Michael Freilich is the latest, are the gold standard when it comes to sea level measurements, which are critical for understanding and monitoring climate change,” said Josh Willis, Sentinel-6 Michael Freilich project scientist at NASA’s Jet Propulsion Laboratory, in a statement. “We can’t lose track of how much sea level has gone up because if we do, it’s hard to predict what’s going to happen in the decades to come.”

This satellite is the first of a pair, with its companion Sentinel-6B set to launch in 2025. Together, they will take long-term records of rising sea levels, which will provide information about the rate of global climate change. In addition, the satellites will also monitor other factors like looking at how water vapor and temperature vary throughout the atmosphere.

“The unprecedented accuracy of the sea level measurements provided by this mission ensures not only the continuity of a 30-year data record, but allows improving our understanding of climate change and the impact of rising seas on coastal areas and communities,” said Julia Figa Saldana, ocean altimetry program manager at the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT).