Information from the U.S.-European Floor Water and Ocean Topography mission offers researchers an in depth take a look at lakes and reservoirs in a U.S. watershed.
The Ohio River Basin stretches from Pennsylvania to Illinois and comprises a system of reservoirs, lakes, and rivers that drains an space virtually as massive as France. Researchers with the SWOT (Floor Water and Ocean Topography) mission, a collaboration between NASA and the French area company CNES (Centre Nationwide d’Études Spatiales), now have a brand new device for measuring water ranges not solely on this space, which is residence to greater than 25 million individuals, however in different watersheds world wide as effectively.
Since early 2023, SWOT has been measuring the peak of almost all water on Earth’s floor — together with oceans, lakes, reservoirs, and rivers — masking almost all the globe at the very least as soon as each 21 days. The SWOT satellite tv for pc additionally measures the horizontal extent of water in freshwater our bodies. Earlier this 12 months, the mission began making validated information publicly obtainable.
“Having these two views — water extent and ranges — on the similar time, together with detailed, frequent protection over massive areas, is unprecedented,” stated Jida Wang, a hydrologist on the College of Illinois Urbana-Champaign and a member of the SWOT science workforce. “This can be a groundbreaking, thrilling side of SWOT.”
Researchers can use the mission’s information on water degree and extent to calculate how the quantity of water saved in a lake or reservoir modifications over time. This, in flip, may give hydrologists a extra exact image of river discharge — how a lot water strikes by way of a specific stretch of river.
The visualization above makes use of SWOT information from July 2023 to November 2024 to point out the typical water degree above sea degree in lakes and reservoirs within the Ohio River Basin, which drains into the Mississippi River. Yellow signifies values better than 1,600 ft (500 meters), and darkish purple represents water ranges lower than 330 ft (100 meters). Evaluating how such ranges change will help hydrologists measure water availability over time in an area space or throughout a watershed.
Traditionally, estimating freshwater availability for communities inside a river basin has been difficult. Researchers collect info from gauges put in at sure lakes and reservoirs, from airborne surveys, and from different satellites that take a look at both water degree or extent. However for ground-based and airborne devices, the protection will be restricted in area and time. Hydrologists can piece collectively a few of what they want from totally different satellites, however the information could or could not have been taken on the similar time, or the researchers would possibly nonetheless want to enhance the knowledge with measurements from ground-based sensors.
Even then, calculating freshwater availability will be sophisticated. A lot of the work depends on pc fashions. “Conventional water fashions typically don’t work very effectively in extremely regulated basins just like the Ohio as a result of they’ve hassle representing the unpredictable conduct of dam operations,” stated George Allen, a freshwater researcher at Virginia Tech in Blacksburg and a member of the SWOT science workforce.
Many river basins in america embody dams and reservoirs managed by a patchwork of entities. Whereas the individuals who handle a reservoir could know the way their part of water behaves, planning for water availability down all the size of a river could be a problem. Since SWOT seems at each rivers and lakes, its information will help present a extra unified view.
“The info lets water managers actually know what different individuals in these freshwater techniques are doing,” stated SWOT science workforce member Colin Gleason, a hydrologist on the College of Massachusetts Amherst.
Whereas SWOT researchers are excited in regards to the prospects that the info is opening up, there may be nonetheless a lot to be accomplished. The satellite tv for pc’s high-resolution view of water ranges and extent means there’s a huge ocean of information that researchers should wade by way of, and it’ll take a while to course of and analyze the measurements.
The SWOT satellite tv for pc was collectively developed by NASA and CNES, with contributions from the Canadian House Company (CSA) and the UK House Company. NASA’s Jet Propulsion Laboratory, managed for the company by Caltech in Pasadena, California, leads the U.S. part of the undertaking. For the flight system payload, NASA offered the Ka-band radar interferometer (KaRIn) instrument, a GPS science receiver, a laser retroreflector, a two-beam microwave radiometer, and NASA instrument operations. The Doppler Orbitography and Radioposition Built-in by Satellite tv for pc system, the twin frequency Poseidon altimeter (developed by Thales Alenia House), the KaRIn radio-frequency subsystem (along with Thales Alenia House and with help from the UK House Company), the satellite tv for pc platform, and floor operations have been offered by CNES. The KaRIn high-power transmitter meeting was offered by CSA.
To study extra about SWOT, go to:
Jane J. Lee / Andrew Wang
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-0307 / 626-379-6874
jane.j.lee@jpl.nasa.gov / andrew.wang@jpl.nasa.gov
2024-176
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Sourcing information and pictures from nasa.gov/information
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