by A NASA-led international satellite mission was scheduled to lift off from Southern California early Thursday as part of a major earth science project to conduct a comprehensive survey of the world’s oceans, lakes and rivers for the first time. world.
Dubbed SWOT, short for ‘surface water and ocean topography’, the advanced radar satellite is designed to give scientists an unprecedented view of the vital fluid that covers 70% of the planet, shedding new light on the mechanisms and consequences of climate change.
A Falcon 9 rocket, owned and operated by billionaire Elon Musk’s commercial launch company SpaceX, was scheduled to lift off before dawn Thursday from US Space Forces Base Vandenberg, about 170 miles (275km) northwest of Los Angeles, to carry SWOT into orbit.
If all goes as planned, the SUV-sized satellite will produce research data within several months.
After nearly 20 years of development, SWOT incorporates advanced microwave radar technology that scientists say will collect surface-height measurements of oceans, lakes, reservoirs and rivers in high-definition detail over more than 90 percent of the globe.
“It’s really the first mission to look at almost all water on the planet’s surface,” said Ben Hamlington, a scientist at NASA’s Jet Propulsion Laboratory (JPL) who also leads NASA’s sea level change team.
A major thrust of the mission is to explore how the oceans absorb atmospheric heat and carbon dioxide in a natural process that moderates global temperatures and climate change.
By scanning the seas from orbit, SWOT is designed to precisely measure subtle differences in surface elevation around smaller currents and eddies, where much of the oceans’ heat and carbon uptake is thought to occur. And SWOT can do it with 10 times the resolution of existing technologies, according to JPL.
It is estimated that the oceans have absorbed more than 90% of the excess heat trapped in the Earth’s atmosphere from human-caused greenhouse gas emissions.
Studying the mechanism by which this happens will help climate scientists answer a key question: ‘What is the inflection point where the oceans begin to release, rather than absorb, huge amounts of heat into the atmosphere and accelerate the global warming, instead of limiting it?” said Nadya Vinogradova Shiffer, SWOT program scientist at NASA in Washington.
SWOT’s ability to discern smaller surface features can also be used to study the impact of rising ocean levels on coastlines.
More accurate data along the tidal zones would help predict how far storm flooding can penetrate inland, as well as the extent of saltwater intrusion into estuaries, wetlands and groundwater aquifers.
Repeatedly inventorying Earth’s water resources during SWOT’s three-year mission will allow researchers to better track fluctuations in the planet’s rivers and lakes during seasonal changes and major weather events.
Tamlin Pavelsky, head of freshwater science at NASA’s SWOT, said collecting such data is like “taking the pulse of the world’s water system, so we’ll be able to see when it’s racing and we’ll be able to see when is slow”. .
SWOT’s radar instrument operates at the so-called Ka-band frequency of the microwave spectrum, allowing scans to penetrate cloud cover and darkness over large areas of the Earth. This allows scientists to accurately map their observations in two dimensions regardless of weather or time of day, and to cover large geographic areas much faster than previously possible.
By comparison, previous studies of water bodies relied on data taken at specific points, such as river or ocean meters, or from satellites that can only plot measurements along a one-dimensional line, requiring scientists to fill in data gaps through extrapolation .
“Rather than giving us a line of elevations, it’s giving us a map of elevations, and that’s just a total game changer,” Pavelsky said.
