02570nas a2200289   4500000000100000000000100001008004100002260000800043653004400051653005500095653005100150653004000201653003000241653003900271653002900310100002200339700001900361700001300380700001600393700001800409245012100427856004300548300001100591490000700602520165700609020001402266       2008                            d  bAGU10a1616 Global Change: Climate variability10a4901 Paleoceanography: Abrupt/rapid climate change10a4954 Paleoceanography: Sea surface temperature10a4962 Paleoceanography: Thermohaline10aDansgaard-Oeschger events10ameridional overturning circulation10anortheast Atlantic Ocean1 aAlexander Dickson1 aWilliam Austin1 aIan Hall1 aMark Maslin1 aMichal Kucera00aCentennial-scale evolution of Dansgaard-Oeschger events in the northeast Atlantic Ocean between 39.5 and 56.5 ka B.P  uhttp://dx.doi.org/10.1029/2008PA001595  aPA32060 v233 aThere is much uncertainty surrounding the mechanisms that forced the abrupt climate fluctuations found in many palaeoclimate records during Marine Isotope Stage (MIS)-3. One of the processes thought to be involved in these events is the Atlantic Meridional Overturning Circulation (MOC), which exhibited large changes in its dominant mode throughout the last glacial period. Giant piston core MD95-2006 from the northeast Atlantic Ocean records a suite of palaeoceanographic proxies related to the activity of both surface and deep water masses through a period of MIS-3 when abrupt climate fluctuations were extremely pronounced. A two-stage progression of surface water warming during interstadial warm events is proposed, with initial warming related to the northward advection of a thin warm surface layer within the North Atlantic Current, which only extended into deeper surface layers as the interstadial progressed. Benthic foraminifera isotope data also show millennial-scale oscillations but of a different structure to the abrupt surface water changes. These changes are argued to partly be related to the influence of low-salinity deepwater brines. The influence of deepwater brines over the site of MD95-2006 reached a maximum at times of rapid warming of surface waters. This observation supports the suggestion that brine formation may have helped to destabilize the accumulation of warm, saline surface waters at low latitudes, helping to force the MOC into a warm mode of operation. The contribution of deepwater brines relative to other mechanisms proposed to alter the state of the MOC needs to be examined further in future studies.  a0883-8305