NASA mission will give unprecedented view of Earth’s surface water | POT

A NASA-led international satellite mission is scheduled to lift off from Southern California Thursday morning as part of a major earth sciences project to conduct a comprehensive study of the world’s oceans, lakes and rivers for the first time. .

Dubbed SWOT, short for “water surface and ocean surveying,” the advanced radar satellite is designed to give scientists unprecedented insight into the life-giving fluid that covers 70% of the planet, shedding new light on the mechanics and the consequences of climate change.

A Falcon 9 rocket, owned and operated by billionaire Elon Musk’s commercial launch company. spacexIt was scheduled to take off before dawn Thursday from the US Space Force Base Vandenberg, about 170 miles (275 km) northwest of Los Angeles, to bring Swot into orbit.

If all goes to plan, the SUV-sized satellite will produce research data within several months.

Nearly 20 years in the making, Swot incorporates advanced microwave radar technology that scientists say will collect height and surface measurements of oceans, lakes, reservoirs, and rivers in high-definition detail over more than 90% of the globe.

“It’s really the first mission to look at almost all the water on the surface of the planet,” said Ben Hamlington, a scientist at NASA’s Jet Propulsion Laboratory (JPL) who also leads NASA’s sea level change team. .

One of the main objectives 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 fine differences in surface elevations around smaller currents and eddies, where much of the oceans’ heat and carbon extraction 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 by man-made greenhouse gas emissions.

Studying the mechanism by which that happens will help climate scientists answer a key question: “What is the tipping point at which the oceans begin to release, rather than absorb, enormous amounts of heat into the atmosphere and accelerate global warming, rather than limit it?” said Nadya Vinogradova Shiffer, a NASA SWOT program scientist in Washington.

SWOT’s ability to discern smaller surface features will also be used to study the impact of ocean level rise on coastlines.

More accurate data along tidal zones would help predict how far inland flooding from storm surges may penetrate, as well as the extent of saltwater intrusion into estuaries, wetlands, and groundwater aquifers.

Inventorying Earth’s water resources repeatedly 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.

NASA SWOT freshwater science lead Tamlin Pavelsky said collecting such data was akin to “taking the pulse of the world’s water system, so we’ll be able to see when it’s running and we’ll be able to see when it’s slow.” . .

Swot’s radar instrument operates in the so-called Ka-band frequency of the microwave spectrum, allowing scans to penetrate cloud cover and darkness over wide swaths of Earth. This allows scientists to accurately map their observations in two dimensions, regardless of weather or time of day, and cover large geographic areas much faster than was previously possible.

By comparison, previous studies of water bodies have relied on data taken at specific points, such as river or ocean gauges, or from satellites that can only track measurements along a one-dimensional line, requiring scientists to fill in the gaps. data gaps through extrapolation.

“Instead of giving us a line of elevations, it gives us a map of elevations, and that’s a total game changer,” Pavelsky said.

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