J. David Neelin

Every few years, the Pacific Ocean rearranges itself: warm water from the east flows toward the coasts of South America, and weather goes haywire for six months. This is El Niño, and its arrivals cannot be predicted precisely, even though there is a rhythm to them. A model with 930 variables shows that noise is to blame—random gusts of wind acting like an invisible conductor.

In a large concert hall, sound bounces off the walls, and even if you stand in a corner, the echo can reveal the shape of the room. That is essentially the problem the authors tackle: how to recover a system's hidden rhythms from the 'echo' in data collected from only part of the system.