Images from the U.S./European Jason-3 satellite show sea surface height with respect to the seasonal cycle and the long-term trend. Blue/magenta colors indicate lower-than-normal sea levels, while yellow/red colors indicate higher-than-normal sea levels. The April 9, 2018 image (left panel) shows most of the ocean at neutral heights (green). A month later (right panel), a red patch is visible along the equator in the Central Pacific. The red area is a downwelling Kelvin wave, traveling eastward along the equator. https://photojournal.jpl.nasa.gov/catalog/PIA22473

The most recent sea-level height data from the NASA/European Ocean Surface Topography Mission/Jason-2 oceanography satellite show the continued eastward progression of a strong wave of warm water, known as a Kelvin wave, now approaching South America.

Recent sea-level height data from NASA Jason-1 altimetric satellite show that continuing weaker-than-normal trade winds in the western and central equatorial Pacific have triggered another strong, eastward moving, warm Kelvin wave.

ElNi?o is experiencing a late-fall resurgence. Sea-level height data from the NASA/European Ocean Surface Topography Mission/Jason-2 oceanography satellite show the equatorial Pacific has triggered a wave of warm water, known as a Kelvin wave.

This image from NASA European Jason-2 satellite shows Kelvin waves of high sea level red/yellow crossing the Pacific Ocean at the equator. The waves can be related to El Niño events.

Pools of warm water known as Kelvin waves can be seen traveling eastward along the equator black line in this image from the NASA/French Space Agency Ocean Surface Topography Mission/Jason-2 satellite.

Sea level data from the U.S.-European satellite Sentinel-6 Michael Freilich shows early signs of a developing El Niño along the equatorial Pacific Ocean. The measurements show Kelvin waves, low waves that can be tens of miles (hundreds of kilometers) wide, moving from west to east at the equator towards the west coast of Ecuador. When they form at the equator, Kelvin waves can move warm water – associated with higher sea levels – from the western Pacific to the eastern Pacific. El Niño is a periodic climate phenomenon that can affect weather patterns around the world. The condition can bring cooler, wetter conditions to the U.S. Southwest and drought to countries in the western Pacific such as Indonesia and Australia. El Niño is characterized by higher sea levels and warmer-than-average ocean temperatures along the western coasts of North and South America. Water expands as it warms, so sea levels tend to be higher in places with warmer water. The climate phenomenon is also associated with a weakening of the trade winds. The Sentinel-6 Michael Freilich satellite data shown here covers a seven-week period between the beginning of March and the end of April 2023. By April 24, Figure A, Kelvin waves had piled up warmer water and higher sea levels (shown in red and white) off the coasts of Peru, Ecuador, and Columbia. A series of Kelvin waves starting in spring is a well-known precursor to an El Niño. The waves seen during March and April 2023 are similar to the ones that preceded the 1997-1998 El Niño, one of the most powerful in recorded history. Satellites like Sentinel-6 Michael Freilich can detect Kelvin waves with an instrument called an altimeter that uses radar signals to measure the height of the ocean's surface. Warmer areas show up as higher sea levels. The satellite, named after former NASA Earth Science Division Director Michael Freilich, is one of two that compose the Copernicus Sentinel-6/Jason-CS (Continuity of Service) mission. Animation available at https://photojournal.jpl.nasa.gov/catalog/PIA25776

Recent sea-level height data from NASA Jason-2 oceanography satellite show a weakening of trade winds in western and central equatorial Pacific during late-January through February has triggered yet another strong, eastward-moving Kelvin wave.

Sea-level height data from NASA U.S./France Jason altimetric satellite during a 10-day cycle ending July 27, 2004, show weaker than normal trade winds in the western and central equatorial Pacific have triggered an eastward moving, warm Kelvin wave.

Robert Youngquist, center, Applied Physics Laboratory lead, received a U.S. Patent plaque for his invention, Surface Acoustic Wave Tag-Based Coherence Multiplexing, during the 2017 Innovation Expo at NASA's Kennedy Space Center in Florida. From left, are Kelvin Manning, Kennedy's associate director; Youngquist; and Dave Makufka, Kennedy's Technology Transfer Program manager. The purpose of the annual two-day expo is to help foster innovation and creativity among the Kennedy workforce. The event included several keynote speakers, training opportunities, an innovation showcase and the KSC Kickstart competition.

This Topex/Poseidon image of sea-surface heights was taken during a 10-day collection cycle ending August 7, 2002. Sea-surface heights are a measure of how much heat is stored in the ocean below to influence future planetary climate events. Since May 2001, there have been a series of warm Kelvin waves--eastward-moving ocean waves that cross the equatorial Pacific in about two months. A sizable one arrived at the South American coast last February, raising the ocean temperature by 2 degrees Celsius (3.6 degrees Fahrenheit) and triggering the National Oceanic and Atmospheric Administration's forecast for a mild El Niño in 2002. There was another wave in June, followed by the current large pool of warm water in the tropical Pacific that is now moving toward the coast of South America at a speed of 215 kilometers (134 miles) a day and will arrive there in three to four weeks, raising ocean temperatures. Scientists will continue to monitor the Pacific closely for further signs of El Niño formation and intensity. http://photojournal.jpl.nasa.gov/catalog/PIA03855

The galaxy cluster called MOO J1142+1527 can be seen here as it existed when light left it 8.5 billion years ago. The red galaxies at the center of the image make up the heart of the galaxy cluster. This color image is constructed from multi-wavelength observations: Infrared observations from NASA's Spitzer Space Telescope are shown in red; near-infrared and visible light captured by the Gemini Observatory atop Mauna Kea in Hawaii is green and blue; and radio light from the Combined Array for Research in Millimeter-wave Astronomy (CARMA), near Owens Valley in California, is purple. In addition to galaxies, clusters also contain a reservoir of hot gas with temperatures in the tens of millions of degrees Celsius/Kelvin. CARMA was used to detect this gas, and to determine the mass of this cluster. http://photojournal.jpl.nasa.gov/catalog/PIA20052

This Chandra X-Ray Observatory image of the mysterious superstar Eta Carinae reveals a surprising hot irner core, creating more questions than answers for astronomers. The image shows three distinct structures: An outer, horseshoe shaped ring about 2 light-years in diameter, a hot inner core about 3 light-months in diameter, and a hot central source less than a light-month in diameter which may contain the superstar. In 1 month, light travels a distance of approximately 489 billion miles (about 788 billion kilometers). All three structures are thought to represent shock waves produced by matter rushing away from the superstar at supersonic speeds. The temperature of the shock-heated gas ranges from 60 million degrees Kelvin in the central regions to 7 million degrees Kelvin on the outer structure. Eta Carinae is one of the most enigmatic and intriguing objects in our galaxy. Between 1837 and 1856, it increased dramatically in brightness to become the most prominent star in the sky except for Sirius, even through it is 7,500 light-years away, more than 80 times the distance to Sirius. This "Great Eruption," as it is called, had an energy comparable to a supernova, yet did not destroy the star, which faded to become a dim star, invisible to the naked eye. Since 1940, Eta Carinae has begun to brighten again, becoming visible to the naked eye. Photo credit: NASA/CXC/SAO

Acting NASA Administrator Sean Duffy, left, his wife Rachel Campos-Duffy, acting NASA Associate Administrator Vanessa Wyche, and acting Kennedy Space Center Director Kelvin Manning, wave as NASA astronauts Zena Cardman, Mike Fincke, JAXA (Japan Aerospace Exploration Agency) astronaut Kimiya Yui, and Roscosmos cosmonaut Oleg Platonov, depart the Neil A. Armstrong Operations and Checkout Building for Launch Complex 39A on NASA's Kennedy Space Center to board the SpaceX Dragon spacecraft for the Crew-11 mission launch, Thursday, July 31, 2025, at NASA’s Kennedy Space Center in Florida. NASA’s SpaceX Crew-11 mission is the eleventh crew rotation mission of the SpaceX Crew Dragon spacecraft and Falcon 9 rocket to the International Space Station as part of the agency’s Commercial Crew Program. Cardman, Fincke, Yui, Platonov are scheduled to launch at 12:09 p.m. EDT, from Launch Complex 39A at the NASA's Kennedy Space Center. Photo Credit: (NASA/Joel Kowsky)

From right to left, Acting NASA Administrator Sean Duffy, his wife Rachel Campos-Duffy, acting NASA Associate Administrator Vanessa Wyche, and Deputy Director of NASA’s Kennedy Space Center, Kelvin Manning, wave as NASA astronauts Zena Cardman, Mike Fincke, JAXA (Japan Aerospace Exploration Agency) astronaut Kimiya Yui, and Roscosmos cosmonaut Oleg Platonov, depart the Neil A. Armstrong Operations and Checkout Building for Launch Complex 39A on NASA's Kennedy Space Center to board the SpaceX Dragon spacecraft for the Crew-11 mission launch, before it was scrubbed due to weather concerns, Thursday, July 31, 2025, at NASA’s Kennedy Space Center in Florida. NASA’s SpaceX Crew-11 mission is the eleventh crew rotation mission of the SpaceX Crew Dragon spacecraft and Falcon 9 rocket to the International Space Station as part of the agency’s Commercial Crew Program. Cardman, Fincke, Yui, and Platonov launched at 11:43 a.m. EDT, Friday, August 1, from Launch Complex 39A at the NASA's Kennedy Space Center. Photo Credit: (NASA/Aubrey Gemignani)

From right to left, Acting NASA Administrator Sean Duffy, his wife Rachel Campos-Duffy, acting NASA Associate Administrator Vanessa Wyche, and Deputy Director of NASA’s Kennedy Space Center, Kelvin Manning, wave as NASA astronauts Zena Cardman, Mike Fincke, JAXA (Japan Aerospace Exploration Agency) astronaut Kimiya Yui, and Roscosmos cosmonaut Oleg Platonov, depart the Neil A. Armstrong Operations and Checkout Building for Launch Complex 39A on NASA's Kennedy Space Center to board the SpaceX Dragon spacecraft for the Crew-11 mission launch, before it was scrubbed due to weather concerns, Thursday, July 31, 2025, at NASA’s Kennedy Space Center in Florida. NASA’s SpaceX Crew-11 mission is the eleventh crew rotation mission of the SpaceX Crew Dragon spacecraft and Falcon 9 rocket to the International Space Station as part of the agency’s Commercial Crew Program. Cardman, Fincke, Yui, and Platonov launched at 11:43 a.m. EDT, Friday, August 1, from Launch Complex 39A at the NASA's Kennedy Space Center. Photo Credit: (NASA/Aubrey Gemignani)

From right to left, Acting NASA Administrator Sean Duffy, his wife Rachel Campos-Duffy, acting NASA Associate Administrator Vanessa Wyche, and Deputy Director of NASA’s Kennedy Space Center, Kelvin Manning, wave as NASA astronauts Zena Cardman, Mike Fincke, JAXA (Japan Aerospace Exploration Agency) astronaut Kimiya Yui, and Roscosmos cosmonaut Oleg Platonov, depart the Neil A. Armstrong Operations and Checkout Building for Launch Complex 39A on NASA's Kennedy Space Center to board the SpaceX Dragon spacecraft for the Crew-11 mission launch, before it was scrubbed due to weather concerns, Thursday, July 31, 2025, at NASA’s Kennedy Space Center in Florida. NASA’s SpaceX Crew-11 mission is the eleventh crew rotation mission of the SpaceX Crew Dragon spacecraft and Falcon 9 rocket to the International Space Station as part of the agency’s Commercial Crew Program. Cardman, Fincke, Yui, and Platonov launched at 11:43 a.m. EDT, Friday, August 1, from Launch Complex 39A at the NASA's Kennedy Space Center. Photo Credit: (NASA/Aubrey Gemignani)