Rising Seas, Rising Concern: How NASA's New Satellite Is Shedding Light on Climate Change

by Born of Water on February 22, 2023

NASA SWOT Satellite

NASA, in collaboration with international space agencies from France, Canada, and the United Kingdom, has recently launched a cutting-edge satellite called the Surface Water and Ocean Topography (SWOT) that will revolutionize our understanding of the world's water. The state-of-the-art device, roughly the size of an SUV, will scan and map oceans, rivers, lakes, and reservoirs, providing scientists with invaluable information about climate-related changes such as hurricane damage, rising seas, and disappearing coastlines.

Using a cloud-penetrating radar, SWOT will scan nearly 90% of the planet's water, with the exception of the poles, to create high-resolution maps. According to Tamlin Pavelsky, the hydrology science lead for the SWOT team, the device can image lakes larger than 15 acres and rivers wider than 330 feet, allowing it to survey millions of lakes and trace approximately 1.3 million miles of rivers. Many of these water bodies are difficult to access by land, making them data-poor.

One of the key advantages of SWOT is its ability to simultaneously measure the extent and height of water, providing a new dimension critical for understanding changes in volume over time. Pavelsky explains that this is made possible by SWOT's Ka-band Radar Interferometer (KaRIn), which sends a 1.5-kilowatt radar pulse to the ground and reads the reflected signal with two antennae at the end of a 33-foot boom. The slight difference between the initial and reflected signals allows the KaRIn to determine the height of water with centimeter accuracy from a distance of almost 900 kilometers away from the surface, improving accuracy by a factor of 100 over existing satellites.

SWOT Data CollectionCredit: NASA/JPL-Caltech: This animation shows how SWOT will collect data over the state of Florida, which is rich with rivers, lakes, and wetlands. Globally, SWOT will measure the height of water in the ocean and in lakes, rivers, and reservoirs on land. 

SWOT will orbit the entire planet and repeat its imaging of every place every 21 days during its three-year mission. By comparing such images, scientists can interpret how water cover is changing over time, providing invaluable information for understanding water availability for crop irrigation in rural areas, measuring the extent of flooding events, and assessing climate vulnerability in developing nations.

The precise satellite data will also help quantify and illustrate the future of sea-level rise, floods, and droughts across the globe. Ben Hamlington, a sea-level rise scientist and SWOT science team member at the NASA Jet Propulsion Laboratory (JPL), notes that the satellite record has shown a rapid increase in sea-level rise along US coastlines over the past three decades. However, he argues that the data means we are not doomed and can use the new information to fend off the most extreme projected outcomes. "Reducing emissions takes some of the higher projections of sea-level rise off the table," he says. "If we can limit warming going forward, we can avoid worst-case scenarios."

The SWOT satellite is a remarkable achievement that will help us better understand and manage the world's water resources. Its high-resolution maps and precise data will provide scientists with invaluable information about climate-related changes, allowing us to make informed decisions about water use, crop irrigation, flood control, and climate mitigation efforts.


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