Steric height, steric height anomaly, sea level and sea level anomaly show that the 1940-41 and the 1982--1983 California ''El Ni¿o'' events were resonant responses of the California Current to the expansion and intensification of the Aleutian low and decreases in strength of the North Pacific high. In both cases, the subsurface anomalies were dynamically produced by onshore transport of Subarctic water and a downward tilt of the inshore thermocline. Sea surface temperature anomalies, however, resulted from thermodynamic as well as dynamic processes. Most previous Californian ''El Ni¿o'' or ''anti-El Ni¿o'' events probably were resonant or anti-resonant responses of the seasonal cycle of the California Current to anomalous large-scale atmospheric forcing.