Large‐scale thermal anomalies in the California Current during the 1982‐1983 El Niño

The large‐scale thermal structure of the California Current during 1982‐83 shows several anomalous conditions: warm sea surface temperature anomalies (∼1‐2°C), depression of the thermocline by 50 m or more, and pronounced subsurface warming (∼3‐4°C) relative to the 30‐year mean. The subsurface anomaly is much greater than the surface anomaly. These persistent (>6 months) structures, coupled with unusually high sea levels along the North American coast, show that a major Californian "El Niño" occurred during 1982‐83. The data support the conclusion that the expansion and intensification of the Aleutian low and the decrease in strength of the Pacific high produced an anomalous basin‐wide atmospheric circulation which coupled directly to the large‐scale oceanic wind‐driven circulation to produce the Californian "El Niño." The enhanced transport from the west (offshore California) and south (Baja California), which such a circulation would produce, is consistent with the observed water properties. The equatorial 1982‐83 El Niño is probably related to the Californian "El Niño" through an atmospheric teleconnection between equatorial sea surface temperature and the atmospheric Hadley circulations.