ENSO_Book_Cover_2020.jpg
Satellite sea surface temperature departure for October 2015 over the Pacific. Orange-red colors indicate above normal temperatures, indicative of an El Niño condition. The 2015-16 El Niño was the first extreme El Niño of the 21st century and among the three strongest El Niños on record. Credit: NOAA National Environmental Satellite, Data, and Information Service (NESDIS)