Holocene temperature variability of the subpolor North Atlantic
by
Mark Chapman
School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK
Coauthors: Harry Elderfield (Department of Earth Sciences, University of Cambridge, Pembroke Street, Cambridge CB2 3SA, UK)

The northward transfer of heat by the surface waters of the subpolar North Atlantic provides a direct linkage between the subtropical ocean and surface conditions in the Nordic Seas which in turn influences the return flow of North Atlantic Deep Water. Recent investigations suggest that the subpolar region has experienced considerable variability during the last 10, 000 years but, at present, compatively little is known about the amplitude of past climatic fluctuations or their significance in the longer term evolution of Holocene climate. We have generated planktonic foraminiferal Mg/Ca and delta¹⁸O measurements through the Holocene section of core NEAP15K (56°N, 28°W, 2848m water depth) in order to evaluate past temperature trends on both millennial and century time scales. These geochemical palaeotemperature estimates are broadly consistent with those results obtained using faunal transfer function and alkenone methods indicating that surface water temperatures have varied by as much as 3-4°C during the course of the Holocene. Some significant differences are evident between the palaeoclimatic patterns identified using the different temperature proxies. These discrepancies are most probably due to the fact that, in some instances, the magnitude of temperature change is not much greater than the precision of the methods being used to derive the palaeotemperature estimates. However, the coherency of some short-term coolings such as the 8.2 ka event, which appears to be recorded by all the proxy methods, suggests that these approaches can provide a reliable indication of surface water variability in the subpolar North Atlantic through the Holocene.

Date received: April 30, 2001

Copyright © 2001 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # cahi-59.