A wave of warm water pooling in the central and eastern Pacific appears as a large area of higher-than-normal sea surface heights in this image from early November.
Published Nov 19, 2009
A trio of globes of sea surface height anomalies shows a deep pulse of warm water—a Kelvin wave—crossing the Pacific Ocean in February 2010. Kelvin waves strengthen and maintain El Niño episodes.
Published Mar 21, 2010
After appearing for two consecutive winters, La Niña appears to be taking some time off.
Published May 4, 2012
These color-coded images show the strengthening of El Niño between October and November 2009. In the November image, warm waters (indicated in red) have spread across the Pacific.
Published Dec 11, 2009
