How do satellites detect the warm water waves signaling El Niño?

Satellites use special tools to feel the warmth of ocean waves that show up when El Niño happens.

Imagine you're swimming in a pool on a sunny day. The water near the surface gets warm because the sun is shining on it. Now, imagine some waves come rolling in, they bring deeper, warmer water from below to the top. That makes the whole pool feel even warmer. Satellites are like super-sensitive thermometers that can see these changes from way up in space.

Satellites have special sensors called infrared detectors, which measure how warm something is by looking at the heat it gives off. When El Niño happens, the ocean’s surface warms up more than usual, just like your skin gets warmer when you come out of a hot bath.

These satellites take pictures of the whole ocean every day. They can tell where the warmest parts are and track how they move, kind of like following a trail of hot footprints across the sea.

It's like being a detective who uses heat maps to follow clues. When warm water waves roll in, it’s like leaving a fingerprint that the satellites can read from far away. This helps scientists know when El Niño is coming and how strong it might be.