Seasonal climate summary southern hemisphere (summer 2015-16): Strong El Niño peaks and begins to weaken

Abstract

Southern hemisphere circulation patterns and associated anomalies for austral summer 2015-16 are reviewed, with an emphasis on the tropical Pacific as well as Australian rainfall and temperatures. Following the peak of El Niño in November 2015, summer 2015-16 featured continued near-record El Niño conditions in the tropical Pacific but saw the emergence of cooler subsurface waters in the equatorial Pacific. A moderate Madden Julian Oscillation (MJO) pulse and positive Southern Annular Mode (SAM) ontributed to average to above average rainfall across much of Australia, while the Maritime Continent and parts of far northern Australia saw continued below average rainfall. Sea surface temperatures during summer 2015-16 were the warmest on record for the southern hemisphere oceans, with very warm ocean temperatures in the Indian Ocean and Australian region, including the warmest summer sea surface temperatures on record around Tasmania. Air temperatures were also warmer than normal across Australia throughout the season, with a significant heatwave in southeast Australia during December.