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The SWOT satellite will collect measurements of how water bodies on Earth change over time. Credit: NASA
The ocean surface generally looks pretty flat. It gets choppy in storms, but otherwise we don’t see much difference in elevation. Yet that appearance is deceiving. Hills, valleys, and slopes contour the ocean surface just as they do the ocean floor. And studying those features can help scientists better understand the role the oceans play in our changing climate.
The best way to study these subtle features is from space. And NASA and the French space agency will do that in a few years with SWOT — the Surface Water and Ocean Topography satellite. It’ll orbit around the poles, providing a view of almost the entire planet every few days. And it will use radar to track the levels of most of the world’s bodies of water.
The craft will have two main goals. One is to map changes in the amount of water in the world’s lakes, rivers, and wetlands. Among other things, that will help scientists better understand how much freshwater empties into the oceans.
The second goal is to map the ocean surface in greater detail than ever before. The satellite will look for bumps or depressions that are as small as a few hundred yards across, and just an inch or two high.
Many of these features are produced by ocean currents. Small-scale currents help transport heat and carbon from the surface to the deep ocean, which helps regulate our planet’s climate. So a better understanding of circulation patterns in the oceans should help improve the models that predict how the climate could change in the decades ahead.
