Climatic interpretation of the recently extended Vostok ice records

Jouzel, Jean; Waelbroeck, C.; Malaize, B.; Bender, Michael L.; Petit, Jean‐Robert; Stiévenard, M.; Barkov, N. I.; Barnola, J. M.; King, T.; Kotlyakov, V. M.; Lipenkov, V.; Lorius, C.; Ritz, Claudia Danielle Andrade; Sowers, Todd

doi:10.1007/s003820050124

Cited by 29 publications

(47 citation statements)

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“…A time-dependent temperature anomaly from the central Greenland GRIP ice core (Dansgaard et al 1993) for the northern hemisphere and from the VOSTOK ice core (Jouzel et al , 1996 for the southern hemisphere has been superimposed on the present-day climatology from ERA40 (Uppala et al 2005) for the temperature forcing of the ISM.…”

Section: Initialization Of the Model And Control Ice Sheetsmentioning

confidence: 99%

Long-term ice sheet–climate interactions under anthropogenic greenhouse forcing simulated with a complex Earth System Model

et al. 2008

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Several multi-century and multi-millennia simulations have been performed with a complex Earth System Model (ESM) for different anthropogenic climate change scenarios in order to study the long-term evolution of sea level and the impact of ice sheet changes on the climate system. The core of the ESM is a coupled coarseresolution Atmosphere-Ocean General Circulation Model (AOGCM). Ocean biogeochemistry, land vegetation and ice sheets are included as components of the ESM. The Greenland Ice Sheet (GrIS) decays in all simulations, while the Antarctic ice sheet contributes negatively to sea level rise, due to enhanced storage of water caused by larger snowfall rates. Freshwater flux increases from Greenland are one order of magnitude smaller than total freshwater flux increases into the North Atlantic basin (the sum of the contribution from changes in precipitation, evaporation, run-off and Greenland meltwater) and do not play an important role in changes in the strength of the North Atlantic Meridional Overturning Circulation (NAMOC). The regional climate change associated with weakening/ collapse of the NAMOC drastically reduces the decay rate of the GrIS. The dynamical changes due to GrIS topography modification driven by mass balance changes act first as a negative feedback for the decay of the ice sheet, but accelerate the decay at a later stage. The increase of surface temperature due to reduced topographic heights causes a strong acceleration of the decay of the ice sheet in the long term. Other feedbacks between ice sheet and atmosphere are not important for the mass balance of the GrIS until it is reduced to 3/4 of the original size. From then, the reduction in the albedo of Greenland strongly accelerates the decay of the ice sheet.

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Section: Initialization Of the Model And Control Ice Sheetsmentioning

confidence: 99%

Long-term ice sheet–climate interactions under anthropogenic greenhouse forcing simulated with a complex Earth System Model

et al. 2008

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“…Dust levels are typically much higher at Vostok during glacial periods than interglacial periods, due to increased aridity and surface winds in the desert source regions, reduced atmospheric moisture and greater aerosol fallout, and to changes in atmospheric circulation (Jouzel and others, 1996;Petit and others, 1999). Consistent with this, Table 2 shows that the dust concentration is relatively high at 399 m (the end of the LGM), 2081 m (the previous ice age), 2875 m (glacial stage 8), 3321 m (glacial stage 12) and 3401 m (glacial stage 14) (Petit and others, 1999;Simões and others, 2002).…”

Section: Impurities: Dustmentioning

confidence: 99%

The microstructure of meteoric ice from Vostok, Antarctica

Obbard

Baker

2007

J. Glaciol.

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ABSTRACT. The 3623 m long, 5G core collected at Vostok station, Antarctica, contains alternating layers of meteoric ice with two distinctly different microstructures. In this paper, we present the microstructure and impurity content of a number of specimens ranging in depth from 97 to 3416 m, describe in detail the characteristics of the different layers and propose a mechanism for their microstructural development. Digital image analysis, ion chromatography, scanning electron microscopy and energy dispersive X-ray spectroscopy were used to measure texture and the location and type of impurities; electron backscatter diffraction was used to determine crystal orientation. The ice associated with interglacial periods is characterized by relatively coarse grains and a strong preferred orientation of the c axes in a plane encompassing the coring direction, producing a vertical-girdle fabric. In contrast, ice from glacial periods is characterized by a much smaller grain size and a strong singlemaximum fabric, where the c axes are clustered around the vertical. Calcium is uniquely present in the grain boundaries of the fine-grained glacial layers, and its effect on grain-boundary mobility and the misorientation dependence of mobility can explain the development of the discontinuous microstructure seen in glacial ice at Vostok station.

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“…The ice cores drilled at Vostok Station (78øS, 106øE) in Antarctica have provided an invaluable continuous record of paleoclimate extending over four glacial-interglacial cycles [Lorius et al, 1985;Jouzel et al, 1993Jouzel et al, , 1996Petit et al, 1997Petit et al, , 1999. Paleoclimatic conditions recorded therein include not only paleotemperatures, established using stable hydrogen isotope ratios [Jouzel et al, 1987], but also atmospheric composition, including gases and aerosols [Barnola et al, 1987 [Blunier et al, 1998] via shared signatory phenomena, as well as some combination of the above [Jouzel et al, , 1996Petit et al, 1997Petit et al, , 1999.…”

Section: Introductionmentioning

confidence: 99%

“…Paleoclimatic conditions recorded therein include not only paleotemperatures, established using stable hydrogen isotope ratios [Jouzel et al, 1987], but also atmospheric composition, including gases and aerosols [Barnola et al, 1987 [Blunier et al, 1998] via shared signatory phenomena, as well as some combination of the above [Jouzel et al, , 1996Petit et al, 1997Petit et al, , 1999. Despite the care put into each construction, the differences between chronologies can be significant even in critical portions of the record, thereby permitting alternative interpretations about the causation of specific paleoclimatic events.…”

Section: Introductionmentioning

confidence: 99%

Dating the Vostok ice core record by importing the Devils Hole chronology

Landwehr¹,

Winograd²

2001

J. Geophys. Res.

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Abstract. The development of an accurate chronology for the Vostok record continues to be an open research question because these invaluable ice cores cannot be dated directly. Depth-to-age relationships have been developed using many different approaches, but published age estimates are inconsistent, even for major paleoclimatic events. We have developed a chronology for the Vostok deuterium paleotemperature record using a simple and objective algorithm to transfer aj•es of major paleoclimatic events from the radiometrically dated 500,000-year 3løO-paleotemperature record from Devils Hole, Nevada. The method is based only on a strong inference that major shifts in paleotemperature recorded at both locations occurred synchronously, consistent with an atmospheric teleconnection. The derived depth-to-age relationship conforms with the physics of ice compaction, and internally produces ages for climatic events 5.4 and 11.24 which are consistent with the externally assigned ages that the Vostok team needed to assume in order to derive their most recent chronology, GT4. Indeed, the resulting V-DH chronology is highly correlated with GT4 because of the unexpected correspondence even in the timing of second-order climatic events that were not constrained by the algorithm. Furthermore, the algorithm developed herein is not specific to this problem; rather, the procedure can be used whenever two paleoclimate records are proxies for the same physical phenomenon, and paleoclimatic conditions forcing the two records can be considered to have occurred contemporaneously. The ability of the algorithm to date the East Antarctic Dome Fuji core is also demonstrated. Despite the care put into each construction, the differences between chronologies can be significant even in critical portions of the record, thereby permitting alternative interpretations about the causation of specific paleoclimatic events. Timing of Paleoclimatic EventsA precise and consistent vocabulary is necessary to discuss and compare the timing of specific paleoclimatic events. Emiliani [1955] defined the concept of marine isotopic stages to be geologic time periods exhibiting distinct paleotemperature ranges as deduced from marine core oxygen isotope time series. He identified a stage boundary to be the midpoint between the maxima and the minima of successive stages. Beginning with the number 1 for the current interglacial period, he assigned increasing integer labels to each successive period, with odd numbers denoting a warm stage and even numbers a cold stage.Broecker

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Climatic interpretation of the recently extended Vostok ice records

Cited by 29 publications

References 0 publications

Long-term ice sheet–climate interactions under anthropogenic greenhouse forcing simulated with a complex Earth System Model

Long-term ice sheet–climate interactions under anthropogenic greenhouse forcing simulated with a complex Earth System Model

The microstructure of meteoric ice from Vostok, Antarctica

Dating the Vostok ice core record by importing the Devils Hole chronology

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