Antarctic ice volume for the last 740 ka calculated with a simple ice sheet model

2005 ◽  
Vol 17 (2) ◽  
pp. 281-287 ◽  
Author(s):  
J. OERLEMANS
Keyword(s):  
Sea Level ◽  
Deep Sea ◽  
Relative Phase ◽  
Ice Sheet ◽  
Ice Cores ◽  
Temperature History ◽  
Glacial Cycle ◽  
Ice Volume ◽  
The Antarctic ◽  
And Sea Level

Fluctuations in the volume of the Antarctic ice sheet for the last 740 ka are calculated by forcing a simple ice sheet model with a sea-level history (from a composite deep sea δ18O record) and a temperature history (from the Dome C deuterium record). Antarctic ice volume reaches maximum values of about 30 × 1015 m3, 3 to 8 ka after glacial maxima [defined as maximum values of the deep sea δ18O record]. Minimum values of ice volume reached in the course of interglacial periods are about 26 × 1015 m3. Most of the time the temperature forcing (larger accumulation) and sea-level forcing (grounding-line retreat) tend to have competing effects. However, towards the end of a glacial cycle, when temperature rises and sea-level is still relatively low, the ice volume reaches a peak. The peak value is very sensitive to the relative phase of the sea-level forcing with respect to the temperature forcing. This is further studied by looking at the response of the model to purely periodic forcings with different relative phase. The large sensitivity of ice sheet size to the phase of the forcings may have some implications for dating of deep ice cores. Care has to be taken by using anchor points from the deep sea record.

scholarly journals The response of a simple Antarctic ice-flow model to temperature and sea-level fluctuations over the Cenozoic era

2007 ◽  
Vol 46 ◽  
pp. 69-77 ◽  
Author(s):  
C.I. Van Tuyll ◽  
R.S.W. Van De Wal ◽  
J. Oerlemans
Keyword(s):  
Sea Level ◽  
Deep Sea ◽  
Flow Model ◽  
Ice Sheet ◽  
Temperature Record ◽  
Ice Flow ◽  
Antarctic Ice Sheet ◽  
Sea Temperature ◽  
Ice Volume ◽  
The Antarctic

AbstractAn ice-flow model is used to simulate the Antarctic ice-sheet volume and deep-sea temperature record during Cenozoic times. We used a vertically integrated axisymmetric ice-sheet model, including bedrock adjustment. In order to overcome strong numerical hysteresis effects during climate change, the model is solved on a stretching grid. The Cenozoic reconstruction of the Antarctic ice sheet is accomplished by splitting the global oxygen isotope record derived from benthic foraminifera into an ice-volume and a deep-sea temperature component. The model is tuned to reconstruct the initiation of a large ice sheet of continental size at 34 Ma. The resulting ice volume curve shows that small ice caps (<107 km3) could have existed during Paleocene and Eocene times. Fluctuations during the Miocene are large, indicating a retreat back from the coast and a vanishing ice flux across the grounding line, but with ice volumes still up to 60% of the present-day volume. The resulting deep-sea temperature curve shows similarities with the paleotemperature curve derived from Mg/Ca in benthic calcite from 25 Ma till the present, which supports the idea that the ice volume is well reproduced for this period. Before 34 Ma, the reproduced deep-sea temperature is slightly higher than is generally assumed. Global sea-level change turns out to be of minor importance when considering the Cenozoic evolution of the ice sheet until 5 Ma.

scholarly journals Last Interglacial climate and sea-level evolution from a coupled ice sheet–climate model

2016 ◽  
Vol 12 (12) ◽  
pp. 2195-2213 ◽  
Author(s):  
Heiko Goelzer ◽  
Philippe Huybrechts ◽  
Marie-France Loutre ◽  
Thierry Fichefet
Keyword(s):  
Surface Temperature ◽  
Sea Level ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Last Interglacial ◽  
A Minor ◽  
The Antarctic ◽  
The Impact ◽  
And Sea Level

Abstract. As the most recent warm period in Earth's history with a sea-level stand higher than present, the Last Interglacial (LIG,  ∼  130 to 115 kyr BP) is often considered a prime example to study the impact of a warmer climate on the two polar ice sheets remaining today. Here we simulate the Last Interglacial climate, ice sheet, and sea-level evolution with the Earth system model of intermediate complexity LOVECLIM v.1.3, which includes dynamic and fully coupled components representing the atmosphere, the ocean and sea ice, the terrestrial biosphere, and the Greenland and Antarctic ice sheets. In this setup, sea-level evolution and climate–ice sheet interactions are modelled in a consistent framework.Surface mass balance change governed by changes in surface meltwater runoff is the dominant forcing for the Greenland ice sheet, which shows a peak sea-level contribution of 1.4 m at 123 kyr BP in the reference experiment. Our results indicate that ice sheet–climate feedbacks play an important role to amplify climate and sea-level changes in the Northern Hemisphere. The sensitivity of the Greenland ice sheet to surface temperature changes considerably increases when interactive albedo changes are considered. Southern Hemisphere polar and sub-polar ocean warming is limited throughout the Last Interglacial, and surface and sub-shelf melting exerts only a minor control on the Antarctic sea-level contribution with a peak of 4.4 m at 125 kyr BP. Retreat of the Antarctic ice sheet at the onset of the LIG is mainly forced by rising sea level and to a lesser extent by reduced ice shelf viscosity as the surface temperature increases. Global sea level shows a peak of 5.3 m at 124.5 kyr BP, which includes a minor contribution of 0.35 m from oceanic thermal expansion. Neither the individual contributions nor the total modelled sea-level stand show fast multi-millennial timescale variations as indicated by some reconstructions.

Ice volume and sea-level changes during Last Glacial Cycle: evidence from marine records

2022 ◽  
pp. 169-170
Author(s):  
Natalia Vázquez-Riveiros ◽  
Samuel Toucanne ◽  
Filipa Naughton ◽  
Teresa Rodrigues ◽  
María Fernanda Sánchez Goñi
Keyword(s):  
Sea Level ◽  
Sea Level Changes ◽  
Glacial Cycle ◽  
Last Glacial ◽  
Ice Volume ◽  
And Sea Level

scholarly journals Nonlinear response of the Antarctic Ice Sheet to late Quaternary sea level and climate forcing

2019 ◽  
Vol 13 (10) ◽  
pp. 2615-2631 ◽  
Author(s):  
Michelle Tigchelaar ◽  
Axel Timmermann ◽  
Tobias Friedrich ◽  
Malte Heinemann ◽  
David Pollard
Keyword(s):  
Sea Level ◽  
Late Quaternary ◽  
Ice Sheet ◽  
Volume Changes ◽  
Antarctic Ice Sheet ◽  
Glacial Ice ◽  
Ice Volume ◽  
Global Sea Level ◽  
The Individual ◽  
The Antarctic

Abstract. Antarctic ice volume has varied substantially during the late Quaternary, with reconstructions suggesting a glacial ice sheet extending to the continental shelf break and interglacial sea level highstands of several meters. Throughout this period, changes in the Antarctic Ice Sheet were driven by changes in atmospheric and oceanic conditions and global sea level; yet, so far modeling studies have not addressed which of these environmental forcings dominate and how they interact in the dynamical ice sheet response. Here, we force an Antarctic Ice Sheet model with global sea level reconstructions and transient, spatially explicit boundary conditions from a 408 ka climate model simulation, not only in concert with each other but, for the first time, also separately. We find that together these forcings drive glacial–interglacial ice volume changes of 12–14 ms.l.e., in line with reconstructions and previous modeling studies. None of the individual drivers – atmospheric temperature and precipitation, ocean temperatures, or sea level – single-handedly explains the full ice sheet response. In fact, the sum of the individual ice volume changes amounts to less than half of the full ice volume response, indicating the existence of strong nonlinearities and forcing synergy. Both sea level and atmospheric forcing are necessary to create full glacial ice sheet growth, whereas the contribution of ocean melt changes is found to be more a function of ice sheet geometry than climatic change. Our results highlight the importance of accurately representing the relative timing of forcings of past ice sheet simulations and underscore the need for developing coupled climate–ice sheet modeling frameworks that properly capture key feedbacks.

scholarly journals Modelled response of the volume and thickness of the Antarctic ice sheet to the advance of the grounded area

2010 ◽  
Vol 51 (55) ◽  
pp. 41-48 ◽  
Author(s):  
Fuyuki Saito ◽  
Ayako Abe-Ouchi
Keyword(s):  
Climate Change ◽  
Sea Level ◽  
Volume Change ◽  
Numerical Experiments ◽  
Ice Sheet ◽  
Ice Shelf ◽  
Antarctic Ice Sheet ◽  
Ice Shelves ◽  
Ice Volume ◽  
The Antarctic

AbstractNumerical experiments are performed for the Antarctic ice sheet to study the sensitivity of the ice volume to variations in the area of grounded ice and to changes in the climate during the most recent deglaciation. The effect of the variations in the grounded area is found to be the major source of changes in the ice volume, while the effect of climate change was minor. The maximum possible contribution of the ice-volume change to sea-level rise during the deglaciation is estimated to be 36 m, which covers most values estimated in previous studies. The effect of the advance of the ice-sheet margin over those regions not connected to the major ice shelves contributes one-third of the total ice-volume change, which is comparable to the effect of the grounding of the Filchner–Ronne Ice Shelf and the contribution of the Ross and Amery Ice Shelves together.

scholarly journals Ice-sheet modelling characteristics in sea-level-based temperature reconstructions over the last glacial cycle

2006 ◽  
Vol 52 (176) ◽  
pp. 149-158 ◽  
Author(s):  
Frank Wilschut ◽  
Richard Bintanja ◽  
Roderik S.W. Van De Wal
Keyword(s):  
Sea Level ◽  
Sediment Cores ◽  
Ice Sheet ◽  
Ice Cores ◽  
Glacial Cycle ◽  
Deep Sea Sediment ◽  
Last Glacial ◽  
Proxy Records ◽  
Temperature Reconstructions ◽  
The Last Glacial

AbstractA widely used method for investigating palaeotemperatures is to analyze local proxy records (e.g. ice cores or deep-sea sediment cores). The interpretation of these records is often not straightforward, and global or hemispheric means cannot be deduced from local estimates because of large spatial variability. Using a different approach, temperature changes over the last glacial cycle can be estimated from sea-level observations by applying an inverse method to an ice-sheet model. In order to understand the underlying physical mechanisms, we used a 1-D ice-sheet model and a 3-D coupled thermodynamic ice-sheet–ice-shelf–bedrock model to investigate the importance of several physical processes for the inverse temperature reconstructions. Results show that (i) temperature reconstructions are sensitive to the employed formulation of mass balance, (ii) excluding thermodynamics in the ice sheet leads to a smaller temperature amplitude in the reconstruction and (iii) hysteresis in the non-linear relation between sea level and temperature occurs as a consequence of ice redistribution in the process of merging and separation of ice sheets. The ice redistribution does not occur if the geometry does not support the formation of a relatively flat dome, which tends to be preserved in warming conditions.

scholarly journals Unravelling the History of Climate Change

1998 ◽  
Vol 10 (3) ◽  
pp. 223-223
Author(s):  
Ian D. Goodwin
Keyword(s):  
Time Series ◽  
Spatial Configuration ◽  
Ice Sheet ◽  
Ice Cores ◽  
Antarctic Ice Sheet ◽  
Ice Volume ◽  
Sheet Surface ◽  
Evolutionary Response ◽  
Climate Records ◽  
The Antarctic

The spatial configuration of the Antarctic ice sheet has fluctuated widely during the Late Quaternary, primarily in response to climate and sea-level forcings. Ice core time-series have long been used as proxy climate records for the Antarctic ice sheet surface and polar atmosphere, and there has been a major multinational effort to drill ice cores on or near the summit of ice domes to retrieve the longest possible records. The annual layering of ice accumulation has afforded high resolution proxy climate records on annual to decadal intervals, spanning a few hundred to hundreds of thousands of years. These time-series have also detailed the changes in the ice sheet surface elevation and dynamics, particularly since the transition from glacial to Holocene climate. However, ice sheet sensitivity to external forcings and the associated fluctuations in ice volume are probably best researched around the ice sheet's margins. The sedimentary record in these circumAntarctic margins holds the key to our unravelling of past and future responses of the Antarctic ice sheet and circumpolar oceans to climate and environmental change, including: fluctuations in ice volume; the distribution of ice shelves; the production of Antarctic bottom water; the variability in the fast ice and pack ice characteristics; biogeochemical cycling and marine productivity; and the evolutionary response of marine and terrestrial species and ecosystems.

scholarly journals Interaction of ice sheets and climate during the past 800 000 years

2014 ◽  
Vol 10 (3) ◽  
pp. 2547-2594
Author(s):  
L. B. Stap ◽  
R. S. W. van de Wal ◽  
B. de Boer ◽  
R. Bintanja ◽  
L. J. Lourens
Keyword(s):  
Temperature Profile ◽  
Sea Level ◽  
Time Scales ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Ice Cores ◽  
Atmospheric Temperature ◽  
The Past ◽  
Long Time ◽  
And Sea Level

Abstract. During the Cenozoic, land ice and climate have interacted on many different time scales. On long time scales, the effect of land ice on global climate and sea level is mainly set by large ice sheets on North America, Eurasia, Greenland and Antarctica. The climatic forcing of these ice sheets is largely determined by the meridional temperature profile resulting from radiation and greenhouse gas (GHG) forcing. As response, the ice sheets cause an increase in albedo and surface elevation, which operates as a feedback in the climate system. To quantify the importance of these climate-land ice processes, a zonally-averaged energy balance climate model is coupled to five one-dimensional ice-sheet models, representing the major ice sheets. In this study, we focus on the transient simulation of the past 800 000 years, where a high-confidence CO2-record from ice cores samples is used as input in combination with Milankovitch radiation changes. We obtain simulations of atmospheric temperature, ice volume and sea level, that are in good agreement with recent proxy-data reconstructions. We examine long-term climate-ice sheet interactions by a comparison of simulations with uncoupled and coupled ice sheets. We show that these interactions amplify global temperature anomalies by up to a factor 2.6, and that they increase polar amplification by 94%. We demonstrate that, on these long time scales, the ice-albedo feedback has a larger and more global influence on the meridional atmospheric temperature profile than the surface-height temperature feedback. Furthermore, we assess the influence of CO2 and insolation, by performing runs with one or both of these variables held constant. We find that atmospheric temperature is controlled by a complex interaction of CO2 and insolation, and both variables serve as thresholds for Northern Hemispheric glaciation.

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