Eugene S. Takle
© 2003
Massive volcanic eruptions launch copious amounts of sulfate and other gases
into the atmosphere that eventually are converted to particulates that encircle
the globe and lead to global cooling before slowly drifting back to the
earth's surface over a period of a couple of years. 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. Their results imply roughly a doubling of the probability of an El
Niño event occurring in the winter following a volcanic eruption, and
that even in year 2 and 3 after such events, El Niños might be more
likely. In years 4, 5, and 6 following eruption, La Niña conditions are
favored. De Silva (2003) provides a very readable summary of the Adams et al.
(2003) results.
References
Adams, J.B., M.E. Mann, and C.M. Ammann, 2003: Proxy evidenced for an El
Niño-like response to volcanic forcing. Nature, 426, 274-278.
de Silva, S., 2003: Eruptions linked to El Niño. Nature,
426, 239-240.