Seasonal climate summary southern hemisphere (summer 2002/03): El Niño begins its decline

Southern hemisphere circulation patterns and associated anomalies for the austral summer 2002/03 are reviewed, with emphasis given to the Pacific Basin climate indicators and Australian rainfall and temperature patterns. Summer 2002/03 saw the beginning of the end of the El Niño which began in winter 2002. Anomalously warm sea surface temperatures in the equatorial Pacific began to retract to the central and western Pacific, with cool subsurface waters undermining warm waters in the east. Off-equatorial Rossby waves, travelling from east to west during 2002, reflected off the Indonesian – Australasian coast to form an upwelling Kelvin wave that traversed east across the equatorial Pacific. Summer rainfall across Australia improved throughout the season, from below average rainfall in late 2002 to well above average in February 2003. Across Australia, summer temperatures were above average, making it the sixth hottest summer since 1950. Bushfires were prevalent in many states with fires burning over two million hectares of parks and forests through Victoria, New South Wales and the Australian Capital Territory.