SWOT

• The data compiled from radar sweeps of the planet at least twice every 21 days, will enhance ocean-circulation models, bolster weather and climate forecasts and aid in managing scarce freshwater supplies in drought-stricken regions.

4. Design of SWOT

• The satellite was designed and built at NASA's Jet Propulsion Laboratory (JPL) near Los Angeles.
• Developed by the U.S. space agency in collaboration with its counterparts in France and Canada, SWOT was one of 15 missions listed by the National Research Council as projects NASA should undertake in the coming decade.
• It's the first mission to observe nearly all water on the planet's surface 
• One major thrust of the mission is to explore how oceans absorb atmospheric heat and carbon dioxide in a natural process that moderates global temperatures and climate change.
• Scanning the seas from orbit, SWOT is designed to precisely measure fine differences in surface elevations around smaller currents and eddies, where much of the ocean's drawdown of heat and carbon is believed to occur.
• SWOT can do so with 10 times greater resolution than existing technologies.

 5. Ocean's tipping point 

• Oceans are estimated to have absorbed more than 90 per cent of the excess heat trapped in Earth's atmosphere by human-caused greenhouse gas emissions.

• SWOT's ability to discern smaller surface features also be used to study the impact of rising ocean levels on coastlines.
• More precise data along tidal zones would help predict how far storm-surge flooding may penetrate inland, as well as the extent of saltwater intrusion into estuaries, wetlands and underground aquifers.

6. Focus on freshwater bodies

• Freshwater bodies are another key focus of SWOT, equipped to observe the entire length of nearly all rivers wider than 330 feet (100 meters) as well as more than 1 million lakes and reservoirs larger than 15 acres (62, 500 square meters).
• Taking inventory of Earth's water resources repeatedly over SWOT's three-year mission will enable researchers to better trace fluctuations in the planet's rivers and lakes during seasonal changes and major weather events.
• NASA's SWOT freshwater science lead, collecting such data was akin to "taking the pulse of the world's water system, will able to see when it's racing and will able to see when it's slow".

7. Ka-band frequency

• SWOT's radar instrument operates at the so-called Ka-band frequency of the microwave spectrum, allowing scans to penetrate cloud cover and darkness over wide swaths of the Earth.
• This enables scientists to accurately map their observations in two dimensions regardless of weather or time of day and to cover large geographic areas far more quickly than before.
• By comparison, previous studies of water bodies relied on data taken at specific points, such as river or ocean gauges or from satellites that can only track measurements along a one-dimensional line, requiring scientists to fill in data gaps through extrapolation.
• Rather than giving us a line of elevations, it's giving a map of elevations and that's just a total game changer.

 For Prelims & Mains

Source: The Indian Express