New French-American Satellite Sparks Hope for Water Management on Earth
2 January 2023
EIRNS—On Dec. 16, a SpaceX rocket launched the Surface Water and Ocean Topography (SWOT) satellite. The first satellite specifically designed to conduct a global survey of Earth’s surface water, SWOT was developed by NASA and France’s National Center for Space Studies (CNES), with contributions from the Canadian and U.K. space agencies. The satellite is a game changer. It is designed to study changes in global water levels and provide, in unprecedented detail, 3D volumetric data for Earth’s oceans and millions of lakes and rivers across 90% of the globe every 21 days. That, of course, if used for the common good, will allow a massive upgrade of overall water management, guaranteeing food production and avoiding droughts and floods.
SWOT’s primary instruments are its nadir altimeter and the Ka-band Radar Interferometer, or KaRIn for short. KaRIn consists of two antennas separated across a 10-meter boom, which independently receive readings the satellite takes of Earth’s surface. Using the satellite’s position data and subsequent phase differences in signal reception, SWOT is capable of measuring water elevations within a 1 cm margin of error.
NASA Earth Science Division Director Karen St. Germain explained the upgrade that SWOT will bring to orbit. “We’ve been doing satellite altimetry measuring sea surface height for 30 years, and that’s a big part of the record we rely on to understand climate change,” she said in response to a question asked by Space.com. “What SWOT will do is give us a tenfold improvement in the spatial resolution of our measurement of water height.” SWOT will be responsible for tracking nearly 2.1 million km of rivers and millions of lakes, and it will be capable of monitoring coastal sea levels to provide oceanic data in corroboration with other on-orbit sources. To help sort through the incredible amount of data, NASA plans to make the mission’s information publicly available and is developing tools to make it easier to access.
Benjamin Hamlington, research scientist for the Sea Level and Ice Group at NASA’s Jet Propulsion Laboratory in Southern California, said during SWOT science briefing on Dec. 13. “Really, anyone who cares about water should be concerned about what SWOT can provide.” Hamlington predicts that SWOT data will be useful for coastal communities, civil engineers, water resource professionals, scientists researching flooding and drought, and more. “Some locations have too much water; others don’t have enough,” he said. “We’re seeing more extreme droughts, more extreme floods; precipitation patterns are changing. It’s really important that we try to understand exactly what is happening using the SWOT data.” (https://www.space.com/spacex-launches-nasa-swot-water-monitoring-satellite ) [kav]