HR: 1340h
AN: PP23B-1427 [Abstracts]
TI: A coral record from the West Pacific Warm Pool (New Georgia)
AU: * Liu, J
EM: jl58@duke.edu
AF: Dept. of Earth and Ocean Sciences, Duke University, Durham, NC 27708
United States
AU: Quinn, T M
EM: tquinn@marine.usf.edu
AF: College of Marine Science, University of South Florida, St. Petersburg, FL 33704
United States
AU: Crowley, T J
EM: tcrowley@duke.edu
AF: Dept. of Earth and Ocean Sciences, Duke University, Durham, NC 27708
United States
AU: Taylor, F W
EM: fred@ig.utexas.edu
AF: Institutes of Geophysics, The University of Texas at Austin, Austin, TX 78759
United States
AU: Hyde, W T
EM: wthyde@duke.edu
AF: Dept. of Earth and Ocean Sciences, Duke University, Durham, NC 27708
United States
AB:
The Western Pacific Warm Pool (WPWP) acts as the heat engine for Earth_s climate and as a major moisture source for the
global hydrological cycle. There is a long-standing uncertainty about the stability of SST changes in this key region. Here
we use elemental ratio (Sr/Ca) and oxygen isotope data from a Porites coral head collected offshore Gizo Island, New Georgia
(8$\circ$ S, 155$\circ$ E), a site that is located in the warmest part of the WPWP, to assess the degree to which changes in
these geochemical variables reflect variations in sea surface conditions. Contrary to other regions, the Sr/Ca and SST
relation is unimpressive in the raw data (r= -0.4). Removal of a PDO (Pacific Decadal Oscillation) signal improves the
correlation (r= -0.67), but it is still less than the normal Sr/SST correlation. The correlation between ENSO filtered Sr/Ca
and SST also shows decadal variations, following the phase shift of PDO index. It is generally highly correlated when
øwarmñ PDO regimes dominated ( $\mid$r$\mid$ = 0.74 $\sim$ 0.88), and poorly correlated when øcoolñ PDO regimes prevailed
( $\mid$r$\mid$ $\leq$ 0.3). We therefore used cyclostationary EOFs to develop a transfer function to isolate the annual
cycle in the Sr/Ca record and get a much more reliable estimate of SST (r= 0.86, from 1932 to 1964). A prediction of the
linear growth rate curve suggests that the bottom of the core is $\sim$ 1706, thus this may be the first coral record with
the potential of extracting a Little Ice Age signal from the WPWP.
DE: 9355 Pacific Ocean
DE: 3344 Paleoclimatology
DE: 4231 Equatorial oceanography
DE: 4267 Paleoceanography
DE: 1050 Marine geochemistry (4835, 4850)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2004 AGU Fall Meeting