Extent and Dynamics of the Scandinavian Ice Sheet during Oxygen Isotope Stage 3 (65,000–25,000 yr B.P.)

2002 ◽  
Vol 57 (1) ◽  
pp. 38-48 ◽  
Author(s):  
Neil S. Arnold ◽  
Tjeerd H. van Andel ◽  
Vidar Valen
Keyword(s):  
Sea Ice ◽  
Oxygen Isotope ◽  
Ice Sheet ◽  
Ice Cover ◽  
Glacial Maximum ◽  
Oxygen Isotope Stage ◽  
Free Interval ◽  
Scandinavian Ice Sheet ◽  
Weichselian Glaciation ◽  
Low Precipitation

AbstractThe climate of the middle Weichselian Glaciation, Marine Oxygen Isotope Stage 3 (OIS-3), a relatively mild period compared to the glacial maxima of OIS-4 and OIS-2, consisted of long warm interstades punctuated by brief cold excursions that grew colder and more frequent with time. The OIS-4 ice sheet is generally thought to have persisted throughout OIS-3, but evidence from dated OIS-3 interstadial deposits suggests that it was swiftly reduced to small remnants which only briefly expanded and retreated. Only 30,000 years ago the deteriorating climate initiated a sustained ice advance leading toward the final glacial maximum of OIS-2. Dynamic ice-sheet models support the existence of a prolonged ice-free interval during OIS-3 induced, perhaps, by low precipitation due to extensive sea-ice cover offshore.

Causes of model–data discrepancies in European climate during oxygen isotope stage 3 with insights from the last glacial maximum

2003 ◽  
Vol 59 (1) ◽  
pp. 108-113 ◽  
Author(s):  
David Pollard ◽  
Eric J. Barron
Keyword(s):  
Oxygen Isotope ◽  
Last Glacial Maximum ◽  
Climate Modeling ◽  
Ice Sheet ◽  
Glacial Maximum ◽  
European Continent ◽  
Oxygen Isotope Stage ◽  
Last Glacial ◽  
The Last Glacial Maximum ◽  
The Last Glacial

AbstractOxygen isotope stage 3 (OIS 3), encompassing the long middle section of the last glacial interval, has been the focus of an intensive high-resolution climate modeling effort for Europe. These model simulations produce substantially colder climates than modern simulations; however, the temperatures appear warmer than many proxy indicators suggest. In order to evaluate the importance of the model boundary conditions, comparable simulations are completed for the last glacial maximum (LGM). The LGM simulation produces a much colder European continent than OIS 3, despite similarities in the specification of sea-surface temperatures (SSTs). Ice-sheet dimension is evidently a key factor in explaining the difference in European climates over the past 40,000 yr. However, underestimates in specified OIS 3 ice sheets cannot be invoked to explain the discrepancies, since data strongly indicate small ice-sheet extents at that time; this leaves errors in specified OIS 3 SSTs as the most likely cause.

Extent and age of the Last Glacial Maximum in the southeastern sector of the Scandinavian Ice Sheet

2001 ◽  
Vol 31 (1-4) ◽  
pp. 407-425 ◽  
Author(s):  
Juha Pekka Lunkka ◽  
Matti Saarnisto ◽  
Valeri Gey ◽  
Igor Demidov ◽  
Vera Kiselova
Keyword(s):  
Last Glacial Maximum ◽  
Ice Sheet ◽  
Glacial Maximum ◽  
Last Glacial ◽  
Scandinavian Ice Sheet ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Reconstruction of sea-surface temperature, salinity, and sea-ice cover in the northern North Atlantic during the last glacial maximum based on dinocyst assemblages

2000 ◽  
Vol 37 (5) ◽  
pp. 725-750 ◽  
Author(s):  
Anne de Vernal ◽  
Claude Hillaire-Marcel ◽  
Jean-Louis Turon ◽  
Jens Matthiessen
Keyword(s):  
Sea Ice ◽  
Surface Temperature ◽  
Last Glacial Maximum ◽  
North Atlantic ◽  
Ice Cover ◽  
Glacial Maximum ◽  
Sea Surface ◽  
Last Glacial ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Past sea-surface conditions over the northern North Atlantic during the last glacial maximum were examined from the study of 61 deep-sea cores. The last glacial maximum time slice studied here corresponds to an interval between Heinrich layers H2 and H1, and spanning about 20-16 ka on a 14C time scale. Transfer functions based on dinocyst assemblages were used to reconstruct sea-surface temperature, salinity, and sea-ice cover. The results illustrate extensive sea-ice cover along the eastern Canadian margins and sea-ice spreading, only during winter, over most of the northern North Atlantic. On the whole, much colder winter prevailed, despite relatively mild conditions in August (10-15°C at most offshore sites), thus suggesting a larger seasonal contrast of temperatures than today. Lower salinity than at present is reconstructed, especially along the eastern Canadian and Scandinavian margins, likely because of meltwater supply from the surrounding ice sheets. These reconstructions contrast with those established by CLIMAP on the basis of planktonic foraminifera. These differences are discussed with reference to the stratigraphical frame of the last glacial maximum, which was not the coldest phase of the last glacial stage. The respective significance of dinocyst and foraminifer records is also examined in terms of the thermohaline characteristics of surface waters and the vertical structure of upper water masses, which was apparently much more stratified than at present in the northern North Atlantic, thus preventing deep-water formation.

Oxygen isotope stage 3 fluvial and eolian successions in Europe compared with climate model results

2003 ◽  
Vol 59 (2) ◽  
pp. 223-233 ◽  
Author(s):  
K.o van Huissteden ◽  
David Pollard
Keyword(s):  
Oxygen Isotope ◽  
Last Glacial Maximum ◽  
Climate Model ◽  
Regional Climate ◽  
Glacial Maximum ◽  
Oxygen Isotope Stage ◽  
Last Glacial ◽  
Wind Speeds ◽  
Fluvial Response ◽  
Eolian Deposits

AbstractFluvial and eolian successions of oxygen isotope stage 3 are compared with global (GCM) and regional climate (RCM) modeling experiments of the stage 3 and last glacial maximum climate in Europe. Differences in precipitation between stage-3 stades and interstades were minor, which is confirmed by the fluvial successions. The fluvial response to climate variation is non-uniform, and in southern Europe more pronounced than in northern Europe. The model simulations indicate a strong western winter circulation over Europe during stage 3, which is supported by the eolian deposits data. Wind speeds in the last glacial maximum simulation appear modest compared with those of stage 3, which contrasts with the abundance of eolian deposits. This suggests that during glacial climates the stabilizing effect of vegetation determines eolian sedimentation rates, rather than wind speed. Stage 3 can be divided into an older part (>45,000 cal yr B.P.) with a relatively stable landscape and moist climate and a younger part with more frequent climate change and decreasing landscape stability.

scholarly journals Investigating the Local Scale Influence of Sea Ice on Greenland Surface Melt

2017 ◽  
Author(s):  
Julienne C. Stroeve ◽  
John R. Mioduszewski ◽  
Asa Rennermalm ◽  
Linette N. Boisvert ◽  
Marco Tedesco ◽  
...  
Keyword(s):  
Sea Ice ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Ice Cover ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Rapid Decline ◽  
Baffin Bay ◽  
Sheet Surface ◽  
Surface Melt

Abstract. Rapid decline in Arctic sea ice cover in the 21st century may have wide-reaching effects on the Arctic climate system, including the Greenland ice sheet mass balance. Here, we investigate whether local changes in sea ice around the Greenland ice sheet have had an impact on Greenland surface melt. Specifically, we investigate the relationship between sea ice concentration, the timing of melt onset and open water fraction surrounding Greenland with ice sheet surface melt using a combination of remote sensing observations, and outputs from a reanalysis model and a regional climate model for the period 1979–2015. Statistical analysis points to covariability between Greenland ice sheet surface melt and sea ice within Baffin Bay and Davis Strait. While some of this covariance can be explained by simultaneous influence of atmospheric circulation anomalies on both the sea ice cover and Greenland melt, within Baffin Bay we find a modest correlation between detrended melt onset over sea ice and the adjacent ice sheet melt onset. This correlation appears to be related to increased transfer of sensible and latent heat fluxes from the ocean to the atmosphere in early sea ice melt years, increasing temperatures and humidity over the ice sheet that in turn initiate ice sheet melt.

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