Rapid switches in subpolar North Atlantic hydrography and climate during the Last Interglacial (MIS 5e)
Ninnemann, Ulysses S.
Galaasen, Eirik V.
Oppo, Delia W.
Kleiven, Helga F.
Darling, Kate F.
MetadataShow full item record
At the peak of the previous interglacial period, North Atlantic and subpolar climate shared many features in common with projections of our future climate, including warmer-than-present conditions and a diminished Greenland Ice Sheet (GIS). Here we portray changes in North Atlantic hydrography linked with Greenland climate during Marine Isotope Stage (MIS) 5e using (sub)centennially sampled records of planktonic foraminiferal isotopes and assemblage counts and ice-rafted debris counts, as well as modern analog technique and Mg/Ca-based paleothermometry. We use the core MD03-2664 recovered from a high accumulation rate site (∼34 cm/kyr) on the Eirik sediment drift (57°26.34′N, 48°36.35′W). The results indicate that surface waters off southern Greenland were ∼3–5°C warmer than today during early MIS 5e. These anomalously warm sea surface temperatures (SSTs) prevailed until the isotopic peak of MIS 5e when they were interrupted by a cooling event beginning at ∼126 kyr BP. This interglacial cooling event is followed by a gradual warming with SSTs subsequently plateauing just below early MIS 5e values. A planktonic δ18O minimum during the cooling event indicates that marked freshening of the surface waters accompanied the cooling. We suggest that switches in the subpolar gyre hydrography occurred during a warmer climate, involving regional changes in freshwater fluxes/balance and East Greenland Current influence in the study area. The nature of these hydrographic transitions suggests that they are most likely related to large-scale circulation dynamics, potentially amplified by GIS meltwater influences.
Author Posting. © American Geophysical Union, 2012. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 27 (2012): PA2207, doi:10.1029/2011PA002244.
Showing items related by title, author, creator and subject.
Ocean climate variability in the eastern North Atlantic during interglacial marine isotope stage 11 : a partial analogue to the Holocene? de Abreu, Lucia; Abrantes, Fatima G.; Shackleton, Nicholas J.; Tzedakis, Polychronis C.; McManus, Jerry F.; Oppo, Delia W.; Hall, Michael A. (American Geophysical Union, 2005-08-30)Similar orbital geometry and greenhouse gas concentrations during marine isotope stage 11 (MIS 11) and the Holocene make stage 11 perhaps the best geological analogue period for the natural development of the present ...
Glacial‐interglacial circulation changes inferred from 231Pa/230Th sedimentary record in the North Atlantic region Gherardi, J.‐M.; Labeyrie, L.; Nave, S.; Francois, Roger; McManus, Jerry F.; Cortijo, E. (American Geophysical Union, 2009-05-02)Studies from the subtropical western and eastern Atlantic Ocean, using the 231Pa/230Th ratio as a kinematic proxy for deep water circulation, provided compelling evidence for a strong link between climate and the rate of ...
The impact of the North Atlantic Oscillation on the uptake and accumulation of anthropogenic CO2 by North Atlantic Ocean mode waters Levine, Naomi M.; Doney, Scott C.; Lima, Ivan D.; Wanninkhof, Rik; Bates, Nicholas R.; Feely, Richard A. (American Geophysical Union, 2011-09-21)The North Atlantic Ocean accounts for about 25% of the global oceanic anthropogenic carbon sink. This basin experiences significant interannual variability primarily driven by the North Atlantic Oscillation (NAO). A suite ...