Ice core evidence for secular variability and 200-year dipolar oscillations in atmospheric circulation over East Antarctica during the Holocene

AbstractMeasurements of the concentration and size distribution of dust particles found in the EPICA (European Project for Ice Coring in Antarctica) Dome C ice core, East Antarctica, provide records covering the last 27000 years. the total concentration decreased drastically by a factor of 55 from the Last Glacial Maximum (LGM) (800 ppb) to the Holocene (15 ppb), with a well-marked absolute minimum around 11500–11600 years ago. This latter almost corresponds to the end of the Younger Dryas in Greenland, which was marked by a methane peak related to the expansion of tropical wetlands. Assuming that the source region forAntarctic dust is the southern part of South America, the Antarctic dust minimum suggests a larger geographical extent for this wet period. the volume (mass)-size distribution of the particles displays a mode which is close to 2 μm in diameter, shifting from 1.9 μm in the glacial period to 2.07 μm in the Holocene. As opposed to previous results from old Dome C, EPICA suggests a greater proportion of large particles in Holocene samples than in LGM samples. In addition, for the period 13 000–2000BP, structured millennial-scale oscillations of the dust mode appear. These are especially well marked before 5000 years ago, with higher frequencies also present. the difference between LGM and Holocene particle distributions may be related to changes in the pattern of dust transport to East Antarctica. At Dome C the greater proportion of coarse particles observed during the Holocene suggests greater direct meridional transport. During the LGM, atmospheric circulation was likely more zonal, causing a greater amount of large dust particles to be removed from the atmosphere before reaching Antarctica. Changes in atmospheric circulation could also be the cause of the millennial-scale dust-mode oscillations during the Holocene.

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Secular variability and 200-year diploar oscillations in an atmospheric circulation over East Antarctica during the Holocene

PAGES news ◽

10.22498/pages.13.3.5 ◽

2005 ◽

Vol 13 (3) ◽

pp. 5-7

Author(s):

B Delmonte ◽

JR Petit ◽

V Maggi

Keyword(s):

Atmospheric Circulation ◽

East Antarctica ◽

The Holocene ◽

Secular Variability

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Late Quaternary environment of southern Windmill Islands, East Antarctica

Antarctic Science ◽

10.1017/s0954102002000202 ◽

2002 ◽

Vol 14 (4) ◽

pp. 385-394 ◽

Cited By ~ 22

Author(s):

HELEN KIRKUP ◽

MARTIN MELLES ◽

DAMIAN B. GORE

Keyword(s):

Late Quaternary ◽

Ice Core ◽

Open Water ◽

Climatic Conditions ◽

East Antarctica ◽

The Holocene ◽

Last Glacial ◽

The Core ◽

Windmill Islands ◽

The Last Glacial

Analyses on a sediment core collected from the Windmill Islands, East Antarctica are used to demonstrate that climatic conditions in this region prior to the Last Glacial Maximum were similar to those during the Holocene and that the area was overrun by ice at some stage between 26 kyr BP and the onset of biogenic sedimentation 11 kyr BP. The 10.9 m long core was taken from a marine inlet (epishelf lake) on Peterson Island and is predominantly a sapropel of Holocene age. Material in the lower part of the core includes a till layer lain down during the last glacial in the region and below this till is material which has been dated to 26 kyr BP. Geochemical analyses conducted on the core demonstrate similarities between the Holocene sequence and the preglacial material. The Holocene sequence shows enhanced biogenic production and periods of open water around 4 kyr BP, suggesting a climatic optimum around that time. A subsequent decline in conditions, probably a colder climate with greater extent of sea ice, is evident from 1 kyr BP to the present. The data support results from ice core studies on nearby Law Dome, which suggest there was a period of warming around 11.5 to 9 kyr BP, that recent summer temperatures are low relative to a few centuries ago, and that increasing winter temperatures are the main contributing factor to a recent overall warming in the region.

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A 700-year record of atmospheric circulation developed from the Law Dome ice core, East Antarctica

Journal of Geophysical Research Atmospheres ◽

10.1029/2002jd002104 ◽

2002 ◽

Vol 107 (D22) ◽

Cited By ~ 30

Author(s):

Joseph M. Souney

Keyword(s):

Atmospheric Circulation ◽

Ice Core ◽

East Antarctica ◽

The Law

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Characteristics and sources of tephra layers in the EPICA-Dome C ice record (East Antarctica): Implications for past atmospheric circulation and ice core stratigraphic correlations

Earth and Planetary Science Letters ◽

10.1016/j.epsl.2005.09.005 ◽

2005 ◽

Vol 239 (3-4) ◽

pp. 253-265 ◽

Cited By ~ 66

Author(s):

B. Narcisi ◽

J.R. Petit ◽

B. Delmonte ◽

I. Basile-Doelsch ◽

V. Maggi

Keyword(s):

Atmospheric Circulation ◽

Ice Core ◽

East Antarctica ◽

Tephra Layers

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Holocene Climatic Records From Antarctic Ice

Annals of Glaciology ◽

10.3189/s0260305500009289 ◽

1990 ◽

Vol 14 ◽

pp. 354-354

Author(s):

J.R Petit ◽

N.I. Barkov ◽

J.P. Benoist ◽

J. Jouzel ◽

Y.S. Korotkevich ◽

...

Keyword(s):

Ice Core ◽

Detailed Comparison ◽

East Antarctica ◽

Polar Regions ◽

Ice Shelf ◽

Temperature Changes ◽

The Holocene ◽

Ross Ice Shelf ◽

Climatic Record ◽

Isotopic Records

The climate of the Holocene is, for continental regions from middle and low latitudes, relatively well documented from pollen studies and other sources. To obtain a global picture, these data must be supplemented by climatic series from polar regions. Such information may be extracted from δD or δ18O ice-core profiles but the interpretation of these isotopic records suffers some limitations, (1) because, expected temperature changes being small, they can be obscured by noise effects in the isotope-temperature relationship, and (2) because they can be influenced, especially in coastal regions, by changes in origin of the ice.With this in mind, we focus our presentation on Dome C and Vostok cores drilled on the East Antarctica Plateau and essentially undisturbed by ice-flow conditions. The detailed comparison between these continuous isotopic records makes it possible to know which part of the isotopic signal is climatically significant. Spectral properties of these two records are also examined over the Holocene period. In addition, we present isotopic results obtained on a 950 m ice core drilled at Komsomolskaia (also on the East Antarctica Plateau) by the Soviet Antarctic Expedition. This core fully covers the Holocene and, although discontinuous, the new data help us to document the East Antarctica isotopic record.From these data, an average climatic record is constructed which shows that the East Antarctica climate was fairly stable during the Holocene, marginally warmest around 10 kyear B.P. and coldest in periods around 1.5 and 6 kyear B P. These features are discussed in relation with other Antarctic data (Byrd, Law Dome, Ross Ice Shelf) and with climate records from both southern and northern hemispheres

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Holocene Climatic Records From Antarctic Ice

Annals of Glaciology ◽

10.1017/s0260305500009289 ◽

1990 ◽

Vol 14 ◽

pp. 354

Author(s):

J.R Petit ◽

N.I. Barkov ◽

J.P. Benoist ◽

J. Jouzel ◽

Y.S. Korotkevich ◽

...

Keyword(s):

Ice Core ◽

Detailed Comparison ◽

East Antarctica ◽

Polar Regions ◽

Ice Shelf ◽

Temperature Changes ◽

The Holocene ◽

Ross Ice Shelf ◽

Climatic Record ◽

Isotopic Records

The climate of the Holocene is, for continental regions from middle and low latitudes, relatively well documented from pollen studies and other sources. To obtain a global picture, these data must be supplemented by climatic series from polar regions. Such information may be extracted from δD or δ18O ice-core profiles but the interpretation of these isotopic records suffers some limitations, (1) because, expected temperature changes being small, they can be obscured by noise effects in the isotope-temperature relationship, and (2) because they can be influenced, especially in coastal regions, by changes in origin of the ice. With this in mind, we focus our presentation on Dome C and Vostok cores drilled on the East Antarctica Plateau and essentially undisturbed by ice-flow conditions. The detailed comparison between these continuous isotopic records makes it possible to know which part of the isotopic signal is climatically significant. Spectral properties of these two records are also examined over the Holocene period. In addition, we present isotopic results obtained on a 950 m ice core drilled at Komsomolskaia (also on the East Antarctica Plateau) by the Soviet Antarctic Expedition. This core fully covers the Holocene and, although discontinuous, the new data help us to document the East Antarctica isotopic record. From these data, an average climatic record is constructed which shows that the East Antarctica climate was fairly stable during the Holocene, marginally warmest around 10 kyear B.P. and coldest in periods around 1.5 and 6 kyear B P. These features are discussed in relation with other Antarctic data (Byrd, Law Dome, Ross Ice Shelf) and with climate records from both southern and northern hemispheres

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Do Greenland Ice Cores Reflect NW European Interglacial Climate Variations?

Quaternary Research ◽

10.1006/qres.1995.1014 ◽

1995 ◽

Vol 43 (2) ◽

pp. 125-132 ◽

Cited By ~ 29

Author(s):

Eiliv Larsen ◽

Hans Petter Sejrup ◽

Sigfus J. Johnsen ◽

Karen Luise Knudsen

Keyword(s):

Western Europe ◽

Ice Core ◽

Greenland Ice Sheet ◽

Ice Cores ◽

High Amplitude ◽

Atlantic Water ◽

Polar Front ◽

Norwegian Sea ◽

The Holocene ◽

Climatic Evolution

AbstractThe climatic evolution during the Eemian and the Holocene in western Europe is compared with the sea-surface conditions in the Norwegian Sea and with the oxygen-isotope-derived paleotemperature signal in the GRIP and Renland ice cores from Greenland. The records show a warm phase (ca. 3000 yr long) early in the Eemian (substage 5e). This suggests that the Greenland ice sheet, in general, recorded the climate in the region during this time. Rapid fluctuations during late stage 6 and late substage 5e in the GRIP ice core apparently are not recorded in the climatic proxies from western Europe and the Norwegian Sea. This may be due to low resolution in the terrestrial and marine records and/or long response time of the biotic changes. The early Holocene climatic optimum recorded in the terrestrial and marine records in the Norwegian Sea-NW European region is not found in the Summit (GRIP and GISP2) ice cores. However, this warm phase is recorded in the Renland ice core. Due to the proximity of Renland to the Norwegian Sea, this area is probably more influenced by changes in polar front positions which may partly explain this discrepancy. A reduction in the elevation at Summit during the Holocene may, however, be just as important. The high-amplitude shifts during substage 5e in the GRIP core could be due to Atlantic water oscillating closer to, and also reaching, the coast of East Greenland. During the Holocene, Atlantic water was generally located farther east in the Norwegian Sea than during the Eemian.

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