Launched in December 2022, the Surface Water and Ocean Topography (SWOT) satellite measures ocean surface topography—i.e., sea surface height. It recently completed its first full 21-day science orbit, which is represented in the above animated globe.

The animation shows sea surface height anomalies around the world: Red and orange indicate ocean heights that were higher than the global mean sea surface height, while blue represents heights lower than the mean. Sea level differences can highlight ocean currents, like the Gulf Stream coming off the U.S. East Coast or the Kuroshio current off the east coast of Japan. Sea surface height can also indicate regions of relatively warmer water—like the eastern part of the equatorial Pacific Ocean during an El Niño—because water expands as it warms.

Sea surface height has been measured by earlier satellites (previously); SWOT does so at a much greater level of detail.