An Unusual El Niño Has Scientists Racing to Learn More

A powerful El Niño is growing in the Pacific Ocean, and scientists say it could be one of the strongest ever recorded. El Niño is a weather pattern that starts when ocean water near the equator gets unusually warm. This causes storms, droughts, and other extreme weather events around the world. To study it up close, NOAA has sent four robotic boats called Saildrones into the Pacific.

NOAA launched the Saildrones from Honolulu, Hawaii. These 23-foot-long robotic vessels are powered by wind and solar energy, so they don't need a crew or fuel. Each one carries 15 sensors that measure things like water temperature, saltiness, and ocean currents. Scientists can steer the drones to wherever they need data most.

The Saildrones ran into a small problem right away. Hurricane Lowell was moving toward Hawaii, so the drones had to be redirected out of its path. Once the storm passed, they continued on their journey toward the equatorial Pacific. Scientists expect the drones to spend about five months collecting measurements in the region.

Michael McPhaden, a researcher who has studied El Niño for nearly 50 years, remembers the big El Niño of 1982. Back then, scientists had no good tools to see it coming or predict what it would do. They didn't fully realize what was happening until it was almost at its peak. That surprise was a 'shock and embarrassment' to the science world.

After 1982, scientists built a much better system for watching the ocean. They set up ocean platforms and satellites around the Pacific over the next decade. Today, that network sends back a steady stream of data. Scientists now have a much clearer picture of what El Niño looks like as it forms.

Even so, there is still a lot to learn. McPhaden compares El Niño to a bonfire — ocean heat is like dry wood, but scientists want to understand what provides the spark. This year, twin cyclones in the Western Pacific may have helped start El Niño by pushing strong winds eastward. Waves of warm water called Kelvin waves also play a role in how these events begin.

Scientists also want to know how El Niño and climate change affect each other. Jhordanne Jones, a professor at Penn State, says El Niño and La Niña are nature's way of balancing the atmosphere. But with climate change, that balance may be shifting in new and unpredictable ways. 'With climate change, the system is hearing a different melody happening, a more irregular type of melody,' she said.

Understanding El Niño better could help people all over the world. Better forecasts could warn farmers about droughts, help cities prepare for floods, and protect fishing communities. Scientists are hopeful the Saildrone data will help answer big questions before the next major El Niño arrives.