MULTIPROXY DATA ACROSS THE LAST TERMINATION I FROM THE NORTH ATLANTIC: OCEAN CIRCULATION AND OCEAN-ICE SHEET INTERACTION
DOKKEN, TROND M. Bjerknes Centre for Climate Research.
Sediment cores from the Nordic Seas/North Atlantic have been investigated in order to reconstruct the phase relationship in different oceanic proxies during rapid transitions in the interval from the last glacial maximum to the Holocene. During the last termination it is possible to identify several modes of circulation that may have significant positive feedback on climate.
In the context of the recent discussion whether the Southern and Northern Hemispheres were out of phase during major re-organisations of climate, it is of major importance to evaluate the phase relationship between changes observed in processes in surface- and deep water and ice sheet dynamics within the Hemispheres. What we observe from the Northern Hemisphere (North Atlantic/Nordic Seas) is that different proxies reflecting changes in deep-water overturning, strength of deep- and surface water flow, surface water cooling and warming, surface water freshening and ice sheet activity, often are out of phase within the same region. These observations show that different processes may well be reflecting responses to different mechanisms. It is therefore important that inter-hemispheric correlation is evaluated in the context of lead and lag within one region.
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