Although the Earth is made up of 75% water, only a small part of it can be used and consumed in daily life. Limited information about the active river systems in the world, could harm the Earth, which in the future could experience a water crisis.
To identify these hidden water sources, the Surface Water and Ocean Topography (SWOT) satellite will map the planet. SWOT will provide a better understanding of the Earth's water cycle, aid in better management of water resources, and broaden knowledge of how climate change affects lakes, rivers and reservoirs.
Developed in collaboration with NASA and the French space agency Center National d'Études Spatial (CNES), the mission will fill a huge gap in data about the planet's water resources.
SWOT Mission
The satellite will measure the height of a body of water on the Earth's surface. SWOT will also be equipped to spot features such as eddies less than 100 kilometers across the ocean. NASA says SWOT will also measure more than 95% of lakes on Earth that are larger than 15 acres and rivers that are more than 330 feet wide.
The spacecraft, in addition to measuring the water level in lakes, rivers, or reservoirs, will also measure its area, or surface area. That vital information will allow scientists to calculate how much water is moving through bodies of fresh water.
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"Current databases may have information on several thousand lakes worldwide. SWOT will push that number to between 2 million and 6 million," said Tamlin Pavelsky, lead NASA freshwater science studies for SWOT.
Scientists have long speculated that climate change is accelerating Earth's water cycle. Warmer temperatures mean the atmosphere can hold more water (in the form of water vapour), which can cause rainstorms to be more intense than typically seen in an area. Such changes could have major consequences for global agriculture and food production.
"As Earth's water cycle intensifies, predicting future extreme events such as floods and droughts requires monitoring both changes in water supply from the ocean and water demand and use on land. A global SWOT view of all surface water on Earth will give us that ," said Nadya Vinogradova Shiffer, SWOT program scientist.
The spacecraft will use a Ka-band Radar Interferometer (KaRIn), which reflects radar pulses from the water's surface and receives a signal back with two antennas at the same time. The radar will be able to gather information along an area of about 120 kilometers on the planet at a time.
"The basic idea of SWOT dates back to the late 1990s, but turning that concept into reality, all of those techniques took a lot of time and effort," says Pavelsky.
The SWOT mission is scheduled to launch in November from Vandenberg Space Force Base in California, United States.