The United States and Europe launched a satellite on Saturday from California to measure the global height of sea level over decades. The SpaceX Falcon 9 rocket carrying the satellite left Vandenberg Air Force Base at 9:17 a.m. and arced toward the Pacific Ocean. The first phase of the Falcon returned to the launch site, where it can be reused.
Sentinel-6 Michael Freilich satellite must deploy its solar panels and make initial contact with controllers. The satellite’s main instrument is a high-precision radio altimeter that fires pulses of energy toward the surface as they fly over the world’s oceans. An identical twin, Sentinel-6B, will be launched in 2025 to ensure continued registration.
Sea level measurements have been carried out without interruption since the launch in 1992 of the French-American satellite TOPEX-Poseidon, followed by others up to the current Jason-3.
The height of the sea level is affected by the warming and cooling of the water, which allows scientists to use the altimeter data to detect phenomena that affect the climate such as El Niño, which is a warm current, and La Niña, which is cold. Measurements are also important for understanding sea level rise due to global warming, which scientists say puts coasts and billions of people at risk.
“Our Earth is a complex system of dynamics connected between the land, the ocean, the ice, the atmosphere and of course our human populations, and that system is changing,” said the director of NASA’s Earth Sciences Division, Karen St. Germain, in a pre-launch conference on Friday.
“Since 70% of the Earth’s surface is ocean, the oceans play a huge role in how the system as a whole changes,” he said. The new satellite is an unprecedented precision. This is an extremely important parameter for climate monitoring, ”Josef Aschbacher, director of Earth observations for the European Space Agency, told The Associated Press.
“We know that the sea level is rising,” Aschbacher said. The big question is by how much and how fast. Other instruments on board will measure how radio signals pass through the atmosphere, providing data on atmospheric temperature and humidity that will help improve weather forecasts.
Europe and the United States share the cost of the mission, of 1 billion dollars (900 million euros), which includes the twin satellites.