USGS hydrologist Heather Best places a water level sensing unit at a tracking gauge in Alaskas Yukon River. SWOT will measure the height of almost all water on Earths surface, from large rivers to lakes and reservoirs to the ocean. These measurements will be important to water management and disaster preparedness firms, universities, civil engineers, and others who need to track water in their local locations.
The quantity of water streaming through such rivers affects whatever from the health and biodiversity of fish types to transportation and drinking water schedule.
Altimeters like those on the Jason series of satellites can determine how water levels differ in some large rivers, and Landsat can measure how river widths differ.
USGS hydrologist Heather Best places a water level sensor at a tracking gauge in Alaskas Yukon River. The states size, rugged surface, and restricted transport facilities make standard stream determining expense prohibitive. Credit: Derek Frohbieter, North Carolina Association of Floodplain Managers
The Surface Water and Ocean Topography objective will supply a chest of information on Earths water resources, even in remote areas. Alaska functions as a case study.
While Alaska straddles the Arctic Circle and is covered by huge stretches of frozen land, the state also has a lot of liquid water. Alaska holds about 40% of U.S. surface water resources. This consists of more than 12,000 rivers, thousands more streams and creeks, and hundreds of countless lakes.
This means that its just natural that Alaska will be among the first recipients of the Surface Water and Ocean Topography (SWOT) satellite, which launched successfully on December 16, 2022, from Californias Vandenberg Space Force Base. This objective is led by NASA and the French space firm Centre National dÉtudes Spatiales (CNES), with contributions from the Canadian Space Agency and the UK Space Agency.
On a tributary of the Atigun River, this is one of just 113 USGS stream gauges in Alaska. SWOT will fill gaps in remote places like Alaska where surface water data is sporadic or nonexistent.
SWOT will determine the height of nearly all water in the worlds surface, from large rivers to lakes and tanks to the ocean. It will complete spaces in remote places like Alaska and in numerous countries where surface water information is nonexistent or sparse. These measurements will be important to water management and disaster preparedness companies, universities, civil engineers, and others who require to track water in their areas.
Alaskas large size, rugged surface, and limited transportation facilities make traditional stream evaluating cost excessive. While streamflows in many of the United States are constantly kept an eye on by a U.S. Geological Survey (USGS) network of more than 8,500 stations, there are presently just 113 determines in Alaska, and numerous huge rivers arent kept track of. The amount of water streaming through such rivers impacts whatever from the health and biodiversity of fish species to transportation and drinking water schedule.
The Surface Water and Ocean Topography (SWOT) objective will help neighborhoods get ready for the effects of a changing climate by gathering information that keeps an eye on the worlds lakes, rivers, tanks, and the ocean. Credit: NASA/JPL-Caltech/CNES/ Thales Alenia Space
SWOT data will complement a system currently in advancement to keep an eye on those rivers, using radar altimetry information from the U.S.-European Jason-2 and -3 and European Space Agency Sentinel satellites (established in the context of the European Copernicus program led by the European Commission), and noticeable imagery from the NASA-USGS Landsat satellites. USGS partners include the Alaska Department of Transportation and Public Facilities, National Weather Services Alaska-Pacific River Forecast Center, U.S. Fish and Wildlife Service, and Alaska Department of Fish and Game.
” Alaska is a location that might particularly benefit from remote observation for streamflow quotes,” said USGS hydrologist Robert Dudley. Dudley said Alaska is a fantastic test case for scientists and water supervisors to work with new space-based tools like SWOT and put them to immediate usage.
USGS is compiling a historical record of approximated stream discharges, constructing on more than 2 decades of NASA research study to measure water surface levels in lakes and rivers. The data will enable researchers and water managers to understand how frequently streams experience low- and high-flow conditions and to develop a recommendation indicate assess current conditions.
Data from SWOT will complement a USGS system currently in development to utilize space-borne instruments– such as Landsat, which captured this image of the Yukon River near Stevens Village, Alaska– to determine the elevation and circulation of Alaskan rivers, the majority of which are currently unmonitored. Credit: USGS
The SWOT Advantage
Dudley states SWOT has numerous advantages over existing satellite-based river measurement strategies. Altimeters like those on the Jason series of satellites can determine how water levels differ in some large rivers, and Landsat can determine how river widths vary. But neither data source by itself offers all the details required to calculate an affordable quote of how much water is flowing through a river without doing expensive and tough on-the-ground calibration. SWOT modifications that by measuring both water levels and width all at once.
If a river has steep banks, it will not necessarily appear larger or narrower as its discharge rate changes. Conversely, even a small change in water elevation in a shallow-banked river can indicate a lot more water is flowing through it.
SWOT will likewise determine a rivers slope, which offers scientists a means to estimate how fast water is running the landscape. Generally speaking, the steeper the slope, the much faster the water.
This illustration reveals the Surface Water and Ocean Topography (SWOT) satellite in orbit with its photovoltaic panels and KaRIn instrument antennas deployed. Credit: CNES
And SWOT will collect the information needed to approximate stream flows at one time, every time it flies over a river, which in Alaska will be about as soon as every 5 days. SWOTs radar also can see through clouds, eliminating data gaps brought on by clouds in Landsat and other visible-light imagery.
Environment change is triggering many hydrological modifications in Alaska that SWOT will help study, said Jack Eggleston, chief of the USGS Hydrologic Remote Sensing Branch. “Rapidly increasing temperature levels are triggering streamflows to increase on the North Slope, where permafrost is melting,” he said. “This is also altering the seasonality of streamflow, with high flows triggered by snow melt occurring earlier in the year.”
” SWOT is going to allow us to see whats going on in Alaska hydrologically in manner ins which we have not previously,” said Tamlin Pavelsky, NASAs SWOT freshwater science lead, based at the University of North Carolina, Chapel Hill. “Thats crucial, because Alaska, being in the Arctic, is likewise the location in the United States experiencing one of the most environment alter today. If you wish to know why that matters, consider how lots of resources we obtain from Alaska.”
More About the Mission
SWOT is being jointly developed by NASA and CNES, with contributions from the CSA and the UK Space Agency. For the flight system payload, NASA is offering the Ka-band Radar Interferometer (KaRIn) instrument, a GPS science receiver, a laser retroreflector, a two-beam microwave radiometer, and NASA instrument operations. CNES is supplying the Doppler Orbitography and Radioposition Integrated by Satellite (DORIS) system, the double frequency Poseidon altimeter (developed by Thales Alenia Space), the KaRIn radio-frequency subsystem (together with Thales Alenia Space and with assistance from the UK Space Agency), the satellite platform, and ground control segment.
