Glacial Inception and Disintegration During the Last Glaciation

Andrews, John T.; Barry, Roger G.

doi:10.1146/annurev.ea.06.050178.001225

Cited by 89 publications

(37 citation statements)

References 57 publications

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“…In the simulations performed with GENESIS2, UGAMP and CCSR1 ice also covers the Keewatin region, while small ice caps are produced in the Labrador sector with LMD5 and CCSR1, and in the Hudson Bay lowland with CCSR1 and UGAMP. Observational data (Andrews and Barry, 1978) indicate that the regions of ice-sheet inception in North America were those bordering the Eastern coast, such as the Baffin Island and the Quebec-Labrador region, as well as the uplands of Northeastern Keewatin. This is concordant with our reconstructions, except for the Labrador sector where small ice caps are only produced with two models.…”

Section: The North American Ice Sheetmentioning

confidence: 99%

Numerical reconstructions of the Northern Hemisphere ice sheets through the last glacial-interglacial cycle

et al. 2007

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Abstract.A 3-dimensional thermo-mechanical ice-sheet model is used to simulate the evolution of the Northern Hemisphere ice sheets through the last glacial-interglacial cycle. The ice-sheet model is forced by the results from six different atmospheric general circulation models (AGCMs). The climate evolution over the period under study is reconstructed using two climate equilibrium simulations performed for the Last Glacial Maximum (LGM) and for the present-day periods and an interpolation through time between these snapshots using a glacial index calibrated against the GRIP δ 18 O record. Since it is driven by the timing of the GRIP signal, the temporal evolution of the ice volume and the ice-covered area is approximately the same from one simulation to the other. However, both ice volume curves and spatial distributions of the ice sheets present some major differences from one AGCM forcing to the other. The origin of these differences, which are most visible in the maximum amplitude of the ice volume, is analyzed in terms of differences in climate forcing. This analysis allows for a partial evaluation of the ability of GCMs to simulate climates consistent with the reconstructions of past ice sheets. Although some models properly reproduce the advance or retreat of ice sheets in some specific areas, none of them is able to reproduce both North American or Eurasian ice complexes in full agreement with observed sea-level variations and geological data. These deviations can be attributed to shortcomings in the climate forcing and in the LGM ice-sheet reconstruction used as a boundary condition for GCM runs, but also to missing processes in the ice-sheet model itself.

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Section: The North American Ice Sheetmentioning

confidence: 99%

Numerical reconstructions of the Northern Hemisphere ice sheets through the last glacial-interglacial cycle

et al. 2007

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“…Thus, little is known about advancing glaciers at the end of the last interglacial, the epoch when climate for the last time was similar to present day. Geological data suggests that ice first grew over the Canadian Arctic islands, Labrador, northern continental Canada, continental western Siberia and Eurasian Arctic islands (Andrews and Barry, 1978;Mangerud and Svendsen, 1992;Clark et al, 1993;Svendsen et al, 2004;Lambeck et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

Warm Nordic Seas delayed glacial inception in Scandinavia

2010

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Abstract.We simulate the last glacial inception, 115 000 years ago, with a three dimensional thermomechanical ice sheet model of the Northern Hemisphere, forced by a comprehensive coupled climate model. High oceanic heat transport into the Nordic Seas prevents large scale ice growth over Scandinavia. Glacial inception in the region starts on the highest mountains in the south when sea surface temperatures in the Nordic Seas are reduced by at least 3 • C.

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“…Insolation characteristics related to the orbital elements have been reexamined recently by BERGER (1978a ANDREWS and BARRY, 1978). Large deviations were absent during the period 65,000 to 32,000 BP and this pattern indicates that recent suggestions (e.g.…”

Section: Possible Causal Factorsmentioning

confidence: 75%

The nature and origin of climatic fluctuations in Northeastern North America

Barry

2011

gpq

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Features of the atmospheric circulation and climate of northeastern Canada are reviewed. In particular, the role of the upper level trough and its variability are discussed. It is shown that longitudinal displacements of the mean summer trough create anomalies of both air temperature and sea ice conditions in the region of Baffin Island. Climatic anomaly patterns in Labrador-Ungava and Keewatin associated with trough displacements are also summarized. Two examples of the application of such information to paleoclimat-ological questions are discussed. One concerns the influx of "exotic" tree pollen into Baffin Island and its previously postulated relationship to southerly airflow. It is concluded that pollen peaks cannot yet be reliably used as a paleowind index. The pattern of glacial inception and ice sheet extension during the Last Glacial Maximum is also briefly considered in the light of the available climatic information. Finally, the role of orbital variations affecting the seasonal pattern of solar radiation is discussed with reference to the last glacial cycle.Nous examinons ici les éléments de la circulation atmosphérique et du climat dans le nord-est du Canada. Nous nous attardons surtout au rôle et à la variabilité du creux barométrique supérieur. Nous voyons que les déplacements longitudinaux du creux barométrique estival moyen engendrent des anomalies tant au niveau des températures de l’air qu’à celui des conditions de la glace marine dans la région de l’île de Baffin. Nous résumons également les types d’anomalies climatiques affectant le Labrador-Ungava et le Keewatin, et associés aux déplacements du creux barométrique. Nous examinons deux cas où des données de ce genre ont été appliquées à des problèmes d’ordre paléoclimatique. Le premier porte sur la présence de pollen issu d’essences exotiques à l’île de Baffin et sur ses relations, considérées possibles, avec les courants atmosphériques venant du sud. Nous concluons qu’il n'est pas encore possible de se fonder sur l’abondance de pollen pour évaluer avec certitude les paléo-vents. Par ailleurs, à la lumière des données climatiques disponibles, nous nous sommes brièvement penchés sur l’amorce des glaciations et l’extension de la calotte glaciaire au cours du dernier maximum glaciaire. Enfin, nous étudions le rôle des variations de l’orbite terrestre, qui affectent selon les saisons le rayonnement solaire, en nous référant à la dernière période glaciaire.Die Karakterzüge der atmosphärischen Zirkulation und das Klima nord-ost Kanadas werden uberprüft. Besonders diskutiert wird die Rolle der Tiefdrucklagen in der Oberschicht und seine Variationen. Es wird gezeigt, dass longitudinale Verschiebungen des Durchschnitts Sommertiefs Anomalien sowohl in Lufttemperaturen als auch in See-Eis Verhältnissen in der Baffin Insel Gegend hervorrufen. Klimatische Anomalien in Labrador Ungava und Keewatin in Verbindung mit Tiefdruck verschiebungen sind auch erwähnt. Zwei Beispiele der Anwendung dieser Information auf paläoklimatische Fragen werden gezeigt. Eines beh...

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Glacial Inception and Disintegration During the Last Glaciation

Cited by 89 publications

References 57 publications

Numerical reconstructions of the Northern Hemisphere ice sheets through the last glacial-interglacial cycle

Numerical reconstructions of the Northern Hemisphere ice sheets through the last glacial-interglacial cycle

Warm Nordic Seas delayed glacial inception in Scandinavia

The nature and origin of climatic fluctuations in Northeastern North America

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