Browsing Bergen Open Research Archive by Author "Ninnemann, Ulysses Silas"
Now showing items 1-8 of 8
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Atlantic Meridional Overturning Circulation and δ13C Variability During the Last Interglacial
Kessler, Augustin; Bouttes, Nathaelle; Roche, Didier M.; Ninnemann, Ulysses Silas; Galaasen, Eirik Vinje; Tjiputra, Jerry (Peer reviewed; Journal article, 2020)The Atlantic Meridional Overturning Circulation (AMOC) is thought to be relatively vigorous and stable during Interglacial periods on multimillennial (equilibrium) timescales. However, recent proxy (δ13C benthic) reconstructions ... -
Deep sea sedimentary analogs for the Vostok ice core
Mortyn, P. Graham; Charles, Christopher D.; Ninnemann, Ulysses Silas; Ludwig, Kristen; Hodell, David A. (Peer reviewed; Journal article, 2003-08-07)Many applications of the Vostok ice core depend critically on the ability to make stratigraphic ties to marine records in the adjacent Southern Ocean. Here we present oxygen isotopic records from high accumulation rate ... -
Evidence for regional cooling, frontal advances, and East Greenland Ice Sheet changes during the demise of the last interglacial
Irvali, Nil; Ninnemann, Ulysses Silas; Kleiven, Helga Flesche; Galaasen, Eirik Vinje; Morley, Audrey; Rosenthal, Yair (Peer reviewed; Journal article, 2016)High-resolution lithic and sea surface climate records are used to portray the progression of North Atlantic climate, hydrography, and Greenland Ice Sheet (GIS) activity through the peak of Marine Isotope Stage (MIS) 5e ... -
Increased ventilation of Antarctic deep water during the warm mid-Pliocene
Zhang, Zhongshi; Nisancioglu, Kerim Hestnes; Ninnemann, Ulysses Silas (Peer reviewed; Journal article, 2013-02-19)The mid-Pliocene warm period is a recent warm geological period that shares similarities with predictions of future climate. It is generally held the mid-Pliocene Atlantic Meridional Overturning Circulation must have been ... -
Magnitude and Origin of the Anthropogenic CO2 Increase and the 13C Suess Effect in the Nordic Seas since 1981
Olsen, Are; Abdirahman, Omar M.; Bellerby, Richard G. J.; Johannessen, Truls; Ninnemann, Ulysses Silas; Brown, Kelly R.; Olsson, K. Anders; Olafsson, Jon; Nondal, Gisle; Kivimäe, Caroline; Kringstad, Solveig; Neill, Craig; Olafsdottir, Solveig (Peer reviewed; Journal article, 2006-09-29)This study evaluates the anthropogenic changes of CO2 (∆Cant) and δ13C (∆δ13Cant) in the Nordic seas, the northern limb of the Atlantic Meridional Overturning Circulation, that took place between 1981 and 2002/03. The ... -
Multidecadal changes in Iceland Scotland Overflow Water vigor over the last 600 years and its relationship to climate
Mjell, Tor Lien; Ninnemann, Ulysses Silas; Kleiven, Helga Flesche; Hall, Ian R. (Peer reviewed; Journal article, 2016-03)Changes in the Atlantic Meridional Overturning Circulation (AMOC) have commonly been invoked to explain the low-frequency climate changes evident over millennial-multidecadal timescales during the Holocene period. While ... -
Pleistocene vertical carbon isotope and carbonate gradients in the South Atlantic sector of the Southern Ocean
Hodell, David A.; Venz, K. A.; Charles, Christopher D.; Ninnemann, Ulysses Silas (Peer reviewed; Journal article, 2003-01-10)We demonstrate that the carbon isotopic signal of mid-depth waters evolved differently from deep waters in the South Atlantic sector of the Southern Ocean during the Pleistocene. Deep sites (>3700 m) exhibit large ... -
Using simulations of the last millennium to understand climate variability seen in palaeo-observations: Similar variation of Iceland-Scotland overflow strength and Atlantic Multidecadal Oscillation
Lohmann, Katja; Mignot, Juliette; Langehaug, Helene Reinertsen; Jungclaus, Johann H.; Matei, Daniela; Otterå, Odd Helge; Gao, Yongqi; Mjell, Tor Lien; Ninnemann, Ulysses Silas; Kleiven, Helga Flesche (Peer reviewed; Journal article, 2015-02-10)A recent palaeo-reconstruction of the strength of the Iceland–Scotland overflow during the last 600 years suggests that its low-frequency variability exhibits strong similarity with palaeo-reconstructions of the Atlantic ...