El Nino is known to be driven by ~0.2 degree changes in the temperature of the surface water of the South Pacific. read more
To prove any relationship with heating from underwater volcanoes, one has to relate the energy produced by volcanoes to the energy capacity of the surface waters of the south pacific. The South Pacific has about 300 million cubic kilometers of water, but the el Nino temperature changes only occur on the surface water, so with an average ocean depth of 4 km, we are only interested in, say, the top meter. read more
Volcanic Eruptions May Affect El Niño Onset A new study by scientists at the University of Virginia (UVa) in Charlottesville and the National Center for Atmospheric Research (NCAR) in Boulder, Colorado, suggests that explosive volcanic eruptions in the tropics may increase the probability of an El Niño event occurring during the winter following the eruption. read more
A more intriguing and controversial impact of volcanoes is their possible regulation of El Niño events. Adams et al. (2003) report correlations between enhanced El Niño activity and recent volcanoes by examining proxy evidenced over a 350 year record. read more