In April of 1997, something interesting happened. El Niños grow because of an unstable interaction between winds and the ocean that works like this: if the ocean warms in the center of the Pacific (where "D" is pointing to in the picture), then the winds tend to get weaker there. But when the winds get weaker, the ocean gets warmer. Then the winds get weaker still, and the process keeps going. For the current El Niño, you first see this starting to happen around April of 1997.
Last modified: 10 October 1997
Copyright © 2000 David W. Pierce. All rights reserved.