A new satellite has been launched that will study most of Earth’s water
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The first mission to study almost all the water on Earth’s surface has been launched.
The international Surface Water and Ocean Surveying mission, known as SWOT, lifted off aboard a SpaceX Falcon 9 rocket from Vandenberg Space Force Base in California at 6:46 a.m. ET on Friday. The rocket’s first stage successfully touched down on Earth at 6:54 am ET.
Live coverage began on NASA website at 6 a.m. ET.
The mission, a joint effort between NASA and the French space agency Center National d’Études Spatiales, will examine water on more than 90% of the world’s surface and measure the height of water in freshwater bodies and in the oceans. . The two agencies have collaborated for decades to monitor Earth’s oceans, and SWOT is the next step in their partnership.
Insights from SWOT measurements will show how the oceans influence climate change and how global warming affects lakes, rivers and reservoirs. Satellite data can also help communities better prepare for flooding and other water-related disasters, which are increasing due to the climate crisis.
While water is critical to the survival of life on Earth, it also shapes our weather and climate by storing and moving carbon and heat trapped in the atmosphere from greenhouse gas emissions. Examining this resource can help scientists understand the global water budget, assessing the major sources, how these sources are changing, and the impacts they will have on different environments.
A key question scientists have is about the exchange of heat between Earth’s atmosphere and the global ocean, and how it could accelerate global warming.
“We will be able to see things that we couldn’t see before,” said Benjamin Hamlington, research scientist in the Ice and Sea Level Group at NASA’s Jet Propulsion Laboratory.
“We will be able to track the movement of water around the Earth between the ocean and the land, we will be able to make some of these connections and really understand where the water is at any given time. This is really critical because we know that with climate change the water cycle is accelerating. What this means is that some places have too much water, others don’t have enough.”
The satellite’s instruments will collect detailed data on oceanic and freshwater features in high definition.
After years of development, SWOT’s Ka Band Radar Interferometer, or KaRIn, is ready to fly. The instrument will be able to detect features that are up to 10 times smaller than those captured by sea level satellites.
For example, current ground and satellite monitoring only collect data on a few thousand of the world’s largest lakes, while SWOT will increase that number to more than 1 million lakes.
Researchers studying bodies of water have had to rely on instruments that take measurements at specific points, such as river or ocean gauges. Similarly, previous space satellites have collected more limited data that cannot plumb the true depths of Earth’s bodies of water. An example of an obstacle to collecting accurate readings is that rivers with steep banks do not appear wider or narrower, even if more water is flowing through them.
But the KaRIn radar instrument can collect measurements through cloud cover and the darkness of night. The two antennas are attached to each end of a 33-foot-long (10-meter-long) arm on the satellite. These antennas send radar pulses to the surface of the water and receive signals back.
“For freshwater, this will be a quantum leap in terms of our knowledge,” Daniel Esteban-Fernandez, KaRIn instrument manager at NASA’s Jet Propulsion Laboratory in Pasadena, California, said in a statement.
The spacecraft will see nearly all rivers larger than 330 feet (100 meters) wide and capture them in 3D for the first time, as well as measure ocean features less than 60 miles (100 kilometers) wide.
“SWOT is really going to allow us to understand how the volume of water in our rivers and lakes changes around the world,” said Tamlin Pavelsky, NASA SWOT Lead Scientist for Freshwater, based at the University of North Carolina, Chapel Hill. “It’s going to be a real game changer.”
SWOT data can help researchers fill in knowledge gaps as they seek to understand the effects of the climate crisis, such as sea level change along coastlines and areas that may be more prone to flooding, to better predict future water level rise.
The climate crisis is also fueling extreme weather patterns, including droughts and downpours. The satellite’s instruments can monitor both and provide essential information for disaster preparedness and water management agencies.
One place in particular that could benefit from SWOT monitoring is Alaska. Although the state sits on the edge of the Arctic Circle, it also holds about 40% of the surface water resources in the US, including more than 12,000 rivers and hundreds of thousands of lakes. The size of the area and rugged terrain, as well as general inaccessibility, have made water measurements in Alaska difficult.
“SWOT is going to allow us to see what’s happening in Alaska hydrologically in ways we haven’t seen before,” Pavelsky said.
“That’s important, because Alaska, being in the Arctic, is also where in the United States is experiencing the most climate change right now. If you want to know why it’s important, think about how much resources we get from Alaska.”
The scope of the SWOT mission means that the satellite will be able to regularly monitor other areas of the world where water resources have previously been difficult to estimate.
“It is going to be transformational in our ability to provide information that will ultimately improve the daily lives and livelihoods of almost everyone here on Earth,” Hamlington said.