HR: 11:05h
AN: U42A-04    [Abstracts]
TI: Century-scale Variabioity in the Atlantic Intertropical Convergence Zone
AU: * Poore, R Z
EM: rpoore@usgs.gov
AF: U.S. Geological Survey, 600 4th Street South, St. Petersburg, Fl 33701 United States
AU: Quinn, T M
EM: quinn@seas.marine.usf.edu
AF: College of Marine Sciences, 140 Seventh Ave South University of South Florida, St. Petersburg, Fl 33702 United States
AB: The abundance of the planktic foraminifer Globigerinoides sacculifer in Gulf of Mexico (GOM) sediments is a proxy for the average position of the Intertropical Convergence Zone (ITCZ). Northward migration of the ITCZ results in increased presence of warm tropical waters in the northern and western GOM; southward migration of the ITCZ results in decreased presence of warm tropical waters in the northern and southern GOM. Abundance variations of G. sacculifer in sediment cores from the GOM show distinct century-scale cyclicity over the last 5,000 years. Spectral analyses of G. sacculifer abundance variations reveal century-scale periodicity that is similar to the century-scale periodicity observed in proxy records of solar activity. The GOM proxy records suggest that the average position of the ITCZ and thus Holocene century-scale variability in the Caribbean-GOM region are linked to solar variability.
DE: 4267 Paleoceanography
DE: 3030 Micropaleontology
DE: 3309 Climatology (1620)
DE: 1600 GLOBAL CHANGE (New category)
DE: 1650 Solar variability
SC: Union [U]
MN: 2004 AGU Fall Meeting