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Oceanic climate and circulation changes during the past four centuries from radiocarbon in corals
Author(s) -
Druffel Ellen R. M.,
Griffin Sheila,
Beaupré Steven R.,
Dunbar Robert B.
Publication year - 2007
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2006gl028681
Subject(s) - radiocarbon dating , oceanography , thermocline , climatology , volcano , walker circulation , geology , coral , ocean current , tropical atlantic , climate change , environmental science , sea surface temperature , paleontology
We analyzed radiocarbon in annual coral bands from the Galápagos Islands in the tropical east Pacific to understand natural variability of past ocean circulation associated with climate change. Variability was observed on El Niño timescales (3–7 years) as well as at decadal and multi‐decadal periods. Low radiocarbon levels persisted for ten years during the early 1600s and for sixteen years during the early 1800s, both coincident with periods of high volcanic aerosol loading in the atmosphere from massive eruptions. Intensification of tropical circulation at this time may be linked to climatically‐controlled changes in the structure of the tropical thermocline that is responsible for delivering cool, upwelled waters to the tropical east Pacific.