Satellite to monitor the rise of the seas with the warming of the climate

An Earth observation satellite developed by European and US space agencies, which is due to take off on Saturday, will measure sea level rise, monitoring changes that threaten to disrupt tens of millions of lives within a generation.

If all goes according to plan, the payload will be hoisted into a low Earth orbit of 1,300 kilometers (800 miles) by a Space X Falcon 9 rocket, taking off from Vandenberg Air Force Base in California at 17:17 GMT.

Sentinel-6a will be the first of two identical satellites, the second to be launched in five years, which will provide unprecedented precision measurements until at least 2030.

Each Sentinel-6 probe carries a radar altimeter, which measures the time it takes for radar pulses to reach the Earth’s surface and back.

The satellites will circle the planet in the same orbit as previous missions that have provided sea surface elevation data for the past three decades, mapping 95% of Earth’s ice-free ocean every ten days.

Accelerating sea level rise is likely the impact of climate change that will affect the largest number of people over the next three decades.

Nearly 800 million people live less than five meters above sea level, and even a sea level rise of just a few centimeters can translate into far greater damage from high tides and storm surges.

Sea level rise is accelerating

Already today, there are more than 100 million people living below high tide levels.

“Extreme sea-level events that are historically rare – once a century in the recent past – are expected to occur frequently, at least annually, in many locations by 2050,” especially in the tropics, the advisory committee of the United Nations climate sciences, IPCC, concluded last year in a major report.

Satellites tracking the world’s oceans since 1993 show that the global mean sea level has increased, on average, by more than three millimeters (more than one-tenth of an inch) per year.

More recently, that rate has increased to 5mm per year.

“It is crucial to be able to see these accelerations,” said Alain Ratier, outgoing Director General of the European Meteorological Satellite Agency, EUMETSAT.

China, Bangladesh, India, Vietnam, Indonesia and Thailand are home to the largest number of people living on land today that could be threatened by permanent flooding by 2100.

The IPCC predicts an increase in global sea level rise to 1.1 meters (43 inches) by the end of the century.

The Copernicus Sentinel-6 mission is a collaboration of the European Commission, the European Space Agency (ESA), EUMETSAT, NASA and the US National Oceanic and Atmospheric Administration (NOAA).

The Sentinel satellites are about the size and shape of a large minivan topped with tilted solar panels and weigh nearly 1,200 kilograms (2,600 lbs), including rocket fuel.

They are designed to last five and a half years, but could provide data for much longer.

© 2020 AFP