SWOT Monitors El Niño off Peru

The illustration above shows sea levels off the coasts of Peru and Ecuador on Aug. 12, 2023, and Oct. 3, 2023. The Surface Water and Ocean Topography (SWOT) satellite collected the ocean data during its operational phase, which began in late July.

The red and orange colors represent sea levels that are higher than average (units are in meters), while green and blue indicate sea levels that are lower than average. The SWOT data shows some of the development of an El Niño along the west coast of the Americas.

The SWOT science team made the measurements using the spacecraft's Ka-band Radar Interferometer (KaRIn) instrument. With two antennas spread 33 feet (10 meters) apart on a boom, KaRIn produces a pair of data swaths (tracks visible in the animation) as it circles the globe, bouncing radar pulses off the water's surface to collect surface-height measurements.

Launched on Dec. 16, 2022, from Vandenberg Space Force Base in central California, SWOT is now in its operations phase, measuring the height of nearly all water on Earth's surface. The satellite will provide one of the most detailed, comprehensive views yet of the planet's oceans and fresh water lakes and rivers, collecting data that will be used for research and other purposes.

SWOT was jointly developed by NASA and CNES, with contributions from the Canadian Space Agency (CSA) and the UK Space Agency. NASA's Jet Propulsion Laboratory, which is managed for the agency by Caltech in Pasadena, California, leads the U.S. component of the project. For the flight system payload, NASA provided the KaRIn instrument, a GPS science receiver, a laser retroreflector, a two-beam microwave radiometer, and NASA instrument operations. CNES provided the Doppler Orbitography and Radioposition Integrated by Satellite (DORIS) system, the dual frequency Poseidon altimeter (developed by Thales Alenia Space), the KaRIn radio-frequency subsystem (together with Thales Alenia Space and with support from the UK Space Agency), the satellite platform, and ground operations. CSA provided the KaRIn high-power transmitter assembly. NASA provided the launch vehicle and the agency's Launch Services Program, based at Kennedy Space Center, managed the associated launch services.