Forces of Change
This world map shows El Niņo sea surface temperatures.

This world map shows El Niņo sea surface temperatures.

This world map shows La Niņa sea surface temperatures.

Top: Normal sea surface temperatures. Middle: Sea surface tempuratures during an El Niņo. Notice the red areas to the west of South America. Bottom: Sea surface tempuratures during a La Niņa. Notice the blue areas to the west of South America. Courtesy of the United States Navy (USN) Fleet Numerical Meteorology and Oceanography Center (FNMOC)