El Niño Comparison (IMAGE) American Geophysical Union Caption This is a comparison of the 2015 and 1997 El Niños, two of the strongest on record, in October of each respective year. Observations of sea surface heights and temperatures, as well as wind patterns, show surface waters cooling off in the Western Pacific and warming significantly in the tropical Eastern Pacific. Credit NASA's Earth Observatory. Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.