Wed. Sep 27th, 2023
El Niño’s Warm Ocean Waters Shift North in the Pacific

Warm ocean waters from the developing El Niño are shifting north along coastlines in the eastern Pacific Ocean. These warm waters are interacting with a persistent marine heat wave along the coast of California, which recently influenced the development of Hurricane Hilary. The Surface Water and Ocean Topography (SWOT) satellite, a collaboration between NASA and the French space agency CNES, is providing unprecedented detail on the movement of these warm ocean waters.

SWOT measures the height of nearly all water on Earth’s surface, offering a comprehensive view of the planet’s oceans and freshwater bodies. As water warms, it expands, resulting in higher sea levels. El Niño, a periodic climate phenomenon, is characterized by higher sea levels and warmer-than-average ocean temperatures along the western coast of the Americas.

The SWOT satellite’s Ka-band Radar Interferometer (KaRIn) instrument measures sea surface heights with high precision. It produces two data swaths as it circles the globe, collecting water-height measurements by bouncing radar pulses off the water’s surface. The visualization of sea surface heights off the U.S. West Coast in August reveals higher-than-average ocean heights in red and orange, and lower-than-average heights in blue and green.

The ability of SWOT to measure sea surface heights close to the coast is invaluable to researchers and forecasters studying phenomena like El Niño. Ben Hamlington, a sea level researcher at NASA’s Jet Propulsion Laboratory, notes that it will aid in understanding the development and progress of El Niño as well as other worldwide weather patterns.

According to the U.S. National Oceanic and Atmospheric Administration’s September outlook, there is a greater than 70% chance of a strong El Niño this coming winter. El Niño is associated with not only warmer water but also a weakening of the equatorial trade winds. This phenomenon can bring cooler, wetter conditions to the U.S. Southwest and drought to countries in the western Pacific.

The SWOT satellite, launched on December 16, 2022, collects data for research purposes. It was jointly developed by NASA and CNES, with contributions from the Canadian Space Agency and the UK Space Agency. SWOT’s mission is led by NASA’s Jet Propulsion Laboratory, and the satellite carries various instruments from both NASA and CNES.

To learn more about the SWOT mission, please visit: