Use NASA’s 2026 observations to explain why expanding warm water lets satellites track subsurface heat.
El Niño is an ocean-atmosphere pattern
El Niño involves warmer-than-normal conditions in parts of the equatorial Pacific and changes in atmospheric circulation. Its effects can reach rainfall and drought patterns far from the ocean. Those tendencies do not dictate identical weather in every place.
Warm water occupies more volume
As seawater warms it expands, raising sea-surface height. Sentinel-6 observations can therefore reveal broad areas where extra heat has accumulated. Scientists remove seasonal cycles and long-term trends when highlighting shorter-lived anomalies linked to the event.
Kelvin waves move heat eastward
When equatorial trade winds weaken or reverse, broad pulses of warm water can travel from the western toward the eastern Pacific. These Kelvin waves deepen the warm layer and suppress the cool upwelling that normally affects the Pacific coast of the Americas.
A reservoir matters more than a skin
A shallow warm surface can change quickly. Elevated sea level indicates heat stored through a deeper layer, which may have greater influence on the developing event. Temperature and height measurements complement rather than replace each other.
Analogy is not a forecast guarantee
NASA compared some June 2026 conditions with the strong 1997 event while also identifying important differences. Similarity at one date cannot lock in the same outcome. Forecasts need continuing ocean and atmosphere observations as the coupled system evolves.
Source
- NASA Earth Observatory — El Niño Is Underway (published 18 June 2026)
Source checked 24 September 2026. General information only; health articles are not medical advice and economy articles are not financial advice.