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PARIS, Nov. 21 (AFP): An Earth-observation satellite developed by European and American space agencies that will take off on Saturday will measure sea level rise, tracking changes that threaten to disrupt tens of millions of lives in a generation.
If all goes according to plan, the payload will be hoisted into a 1,300-kilometer (800-mile) low Earth orbit 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, providing 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 travel to the Earth’s surface and return.
The satellites will circle the planet in the same orbit as previous missions that provided sea-surface height data for the past three decades, mapping 95 percent of Earth’s ice-free ocean every ten days.
The accelerated rise in sea level is possibly the impact of climate change that will affect the greatest number of people during the next three decades.
Almost 800 million people live less than five meters from sea level, and even a rise in sea level of a few centimeters can translate into much more damage from high tides and storm surges.
– Accelerated sea level rise –
Today, more than 100 million people live below high tide levels.
“Extreme sea level events that are historically rare, once a century in the recent past, are projected to occur frequently, at least once a year, in many places by 2050,” especially in the tropics, according to the UN’s climate science advisory panel, the IPCC, concluded in a major report last year.
Satellites tracking the world’s oceans since 1993 show that global mean sea level has risen, on average, by more than three millimeters (more than one-tenth of an inch) a year.
More recently, that rate has increased to 5mm per year.
“It is crucial that we can 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 today living on lands that could be threatened by permanent flooding by 2100.
The IPCC forecasts a rise in global sea level of up 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).
Sentinel satellites are roughly the size and shape of a large minivan with tilted solar panels and weigh nearly 1,200 kilograms (2,600 pounds), including rocket fuel.
They are designed to last five and a half years, but could provide data for much longer. – AFP
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