High Atlantic native Black

Core/Site name:

PL07-73 BC

Country/Region:

Cariaco Basin

Elevation:

-450

Archive:

marine sediments (downcore)

Species:

Globigerina bulloides

Proxy measurement:

Mg/Ca

Sampling resolution:

annual

Climate sensitivity:

March-April-May SST

Dating resolution:

see comments

Dating information:

see comments

Startyear:

1221 AD

Endyear:

1990 AD

All uncertainties:

(1) (2) unclear (3)±0.06 mmol/kg (4)±0.08mmol/kg (±0.4°C)

Description:

We present the first direct comparison and calibration of a downcore foraminiferal Mg/Ca record to historical instrumental sea surface temperature (SST). Mg/Ca measured on the planktic foraminifer Globigerina bulloides from a Cariaco Basin sediment core strongly correlate with spring (March–May) instrumental SSTs between A.D. 1870 and 1990. A Mg/Ca SST equation is derived and a paleo-SST record is presented spanning the last 8 centuries, an interval that includes the end of the Medieval Warm Period and the Little Ice Age. The long-term record displays a surprising amount of variability. The temperature swings are not necessarily related to local upwelling variability but instead represent wider conditions in the Caribbean and western tropical Atlantic. The Mg/Ca SST record also captures the decadal and multidecadal variability observed in records of global land and sea surface temperature anomalies and Atlantic tropical storm and hurricane frequency over the late nineteenth and twentieth centuries. A divergence between the SST proxy record and Atlantic storm frequency around 1970 appears to reflect a fundamental change in Atlantic hurricane behavior noted in historical data. On average, twentieth-century temperatures are not the warmest in the entire record, but they do show the largest increase in magnitude and fastest rate of SST change over the last 800 years.

Data entered by name:

Delia Oppo

Data entered by email:

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Main reference(s):

Black, D.E., M.A. Abahazi, R.C. Thunell, A. Kaplan, E.J. Tappa, and L.C. Peterson. 2007. An 8-century tropical Atlantic SST record from the Cariaco Basin: Baseline variability, twentieth-century warming, and Atlantic hurricane frequency. Paleoceanography, 22, PA4204.

Link to reference 1:

http://www.agu.org/pubs/crossref/2007/2007PA001427.shtml

Link to reference 2:

http://www.agu.org/pubs/crossref/2004/2003PA000982.shtml

Data storage link 1:

http://hurricane.ncdc.noaa.gov/pls/paleox/f?p=519:1:1527603787540765::::P1_STUDY_ID:6397

Comments:

From publication:The age model for the last 130 a of PL07-73 BC isbased on correlations of its foraminiferal census counts to the faunal data of nearby cores with a previously published well-established varve and 210Pb stratigraphy, while the older parts of the core are constrained by a correlative chronology based on 17 accelerator mass spectrometry 14C dates [Black et al., 1999; Goni et al., 2003; Black et al. 2004].

Current dating method:

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Annual snow acc rate:

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Category: Ocean2k