NASA released satellite maps tracing this year’s El Niño through ocean height, surface temperature and color. Warmer water has moved east across the Pacific, and some equatorial waters have become bluer as phytoplankton decline. The observations compare conditions with the previous year’s weak La Niña and show the changing supply of nutrient-rich water at the surface.
NASA, the US space agency, published maps on October 15 showing how El Niño is changing ocean height, temperature and color. The natural climate pattern brings exceptional warmth to sections of the Pacific near the equator. A warm-water movement observed near Micronesia in January preceded its eastward spread. Known as a Kelvin wave, this type of long pulse transports heat across the ocean. Warm water reached the eastern Pacific in early April.[1]
Some areas stood 30–40 centimeters higher as their warmer water expanded. Around Indonesia and northern Australia, the measured level was instead 15–20 centimeters below normal. The Sentinel-6 ocean-monitoring satellites measure sea height every 10 days. In the eastern Pacific the surface was warmer than its long-term average by about 1.7 degrees Celsius. The temperature measurements combine satellites, ships and buoys, and the maps compare this year with the previous year’s weak La Niña.[1]
Launched in 2024, NASA’s ocean-color mission PACE is now following an El Niño for the first time. Hundreds of light wavelengths are measured by the satellite’s Ocean Color Instrument. Some equatorial waters appear bluer as phytoplankton, the microscopic organisms underpinning marine food webs, become less abundant. Weaker trade winds reduce the rise of nutrient-rich deep water to the surface, limiting the supply that supports these organisms. Changes in that food supply can alter where other marine animals feed.[1]
