A Satellite to Understand Rising Sea Levels
The NASA has launched a new satellite dedicated to observing the world’s oceans in order to monitor sea level rise, a phenomenon directly linked to climate change. The mission also aims to improve weather forecasting, particularly in coastal regions that are highly exposed to storms.
By collecting extremely precise ocean data, the satellite will help scientists better understand climate evolution, anticipate natural hazards, and support adaptation strategies in response to rising seas worldwide.
Sentinel-6 Michael Freilich: An International Mission
The satellite Sentinel-6 Michael Freilich was launched from California on November 21, 2020. It is part of a joint program between NASA and the European Space Agency, designed to ensure continuous monitoring of global sea levels over the next decade.
A second satellite, Sentinel-6B, is scheduled for launch in about five years to guarantee continuity of measurements. This international cooperation strengthens the reliability of climate data used by researchers around the world.
How the Satellite Measures Sea Level
To measure sea level, Sentinel-6 uses radar altimetry technology. It sends electromagnetic signals toward the ocean surface and calculates the time it takes for them to return to the satellite.
This method provides extremely accurate measurements, making it possible to detect even small variations in sea level and to track their long-term evolution.
More Accurate Weather Forecasts Near Coastlines
Thanks to its improved resolution, the satellite can observe the oceans much closer to coastlines. This leads to more accurate weather forecasts, especially just before storms or hurricanes make landfall.
As a storm develops over the sea, water levels rise. Sentinel-6 detects this increase and transmits critical information that helps anticipate storm surges, coastal flooding, and other marine hazards.
Sea Level Rise and Its Causes
According to the NOAA, global mean sea level has risen by approximately 21 to 24 centimeters since 1880, with nearly one third of that increase occurring over the last 25 years. Between 2018 and 2019 alone, sea level rose by 6.1 mm.
This rise is mainly caused by the thermal expansion of seawater as the oceans warm, along with melting glaciers and ice sheets, making flooding and coastal inundation more frequent and more dangerous.
A Major Challenge for the Future of Populations
The data collected by Sentinel-6 will help scientists and governments better anticipate the social and environmental impacts of rising sea levels, which could force millions of people to leave coastal areas.
As emphasized by Thomas Zurbuchen, the question is no longer whether sea levels are rising, but what the impact will be on our societies and what actions can be taken to protect future generations.
