The Atlantic Meridional Overturning Circulation's impact on surface climate and subsurface ocean temperatures under the Last Glacial Maximum conditions: a model-data comparison

2012 ◽  
Vol 279-280 ◽  
pp. 230
Author(s):  
Masa Kageyama
Keyword(s):  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
Model Data ◽  
Last Glacial ◽  
Data Comparison ◽  
Surface Climate ◽  
Subsurface Ocean ◽  
Meridional Overturning ◽  
The Last Glacial Maximum ◽  
The Last Glacial

scholarly journals The Last Glacial Maximum and Heinrich Event 1 in terms of climate and vegetation around the Alboran Sea: a preliminary model-data comparison

2005 ◽  
Vol 337 (10-11) ◽  
pp. 983-992 ◽  
Author(s):  
Masa Kageyama ◽  
Nathalie Combourieu Nebout ◽  
Pierre Sepulchre ◽  
Odile Peyron ◽  
Gerhard Krinner ◽  
...  
Keyword(s):  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
Model Data ◽  
Last Glacial ◽  
Data Comparison ◽  
Heinrich Event ◽  
Preliminary Model ◽  
The Last Glacial Maximum ◽  
Heinrich Event 1 ◽  
The Last Glacial

scholarly journals How cold was Europe at the Last Glacial Maximum? A synthesis of the progress achieved since the first PMIP model-data comparison

2007 ◽  
Vol 3 (2) ◽  
pp. 331-339 ◽  
Author(s):  
G. Ramstein ◽  
M. Kageyama ◽  
J. Guiot ◽  
H. Wu ◽  
C. Hély ◽  
...  
Keyword(s):  
Last Glacial Maximum ◽  
General Circulation ◽  
General Circulation Models ◽  
Glacial Maximum ◽  
Model Data ◽  
Last Glacial ◽  
Data Comparison ◽  
The Last Glacial Maximum ◽  
Winter Cooling ◽  
The Last Glacial

Abstract. The Last Glacial Maximum has been one of the first foci of the Paleoclimate Modelling Intercomparison Project (PMIP). During its first phase, the results of 17 atmosphere general circulation models were compared to paleoclimate reconstructions. One of the largest discrepancies in the simulations was the systematic underestimation, by at least 10°C, of the winter cooling over Europe and the Mediterranean region observed in the pollen-based reconstructions. In this paper, we investigate the progress achieved to reduce this inconsistency through a large modelling effort and improved temperature reconstructions. We show that increased model spatial resolution does not significantly increase the simulated LGM winter cooling. Further, neither the inclusion of a vegetation cover compatible with the LGM climate, nor the interactions with the oceans simulated by the atmosphere-ocean general circulation models run in the second phase of PMIP result in a better agreement between models and data. Accounting for changes in interannual variability in the interpretation of the pollen data does not result in a reduction of the reconstructed cooling. The largest recent improvement in the model-data comparison has instead arisen from a new climate reconstruction based on inverse vegetation modelling, which explicitly accounts for the CO2 decrease at LGM and which substantially reduces the LGM winter cooling reconstructed from pollen assemblages. As a result, the simulated and observed LGM winter cooling over Western Europe and the Mediterranean area are now in much better agreement.

scholarly journals Southern Hemisphere westerly wind changes during the Last Glacial Maximum: model-data comparison

2013 ◽  
Vol 64 ◽  
pp. 104-120 ◽  
Author(s):  
Louise C. Sime ◽  
Karen E. Kohfeld ◽  
Corinne Le Quéré ◽  
Eric W. Wolff ◽  
Agatha M. de Boer ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
Westerly Wind ◽  
Model Data ◽  
Last Glacial ◽  
Data Comparison ◽  
The Last Glacial Maximum ◽  
The Last Glacial

scholarly journals How cold was Europe at the Last Glacial Maximum? A synthesis of the progress achieved since the first PMIP model-data comparison

2007 ◽  
Vol 3 (1) ◽  
pp. 197-220 ◽  
Author(s):  
G. Ramstein ◽  
M. Kageyama ◽  
J. Guiot ◽  
H. Wu ◽  
C. Hély ◽  
...  
Keyword(s):  
Last Glacial Maximum ◽  
General Circulation ◽  
General Circulation Models ◽  
Glacial Maximum ◽  
Model Data ◽  
Last Glacial ◽  
Data Comparison ◽  
The Last Glacial Maximum ◽  
Winter Cooling ◽  
The Last Glacial

Abstract. The Last Glacial Maximum has been one of the first foci of the Paleoclimate Modelling Intercomparison Project (PMIP). During its first phase, the results of 17 atmosphere general circulation models were compared to paleoclimate reconstructions. One of the largest discrepancies in the simulations was the systematic underestimation, by at least 10°C, of the winter cooling over Europe and the Mediterranean region observed in the pollen-based reconstructions. In this paper, we investigate the progress achieved to reduce this inconsistency through a large modelling effort and improved temperature reconstructions. We show that increased model spatial resolution does not significantly increase the simulated LGM winter cooling. Further, neither the inclusion of a vegetation cover compatible with the LGM climate, nor the interactions with the oceans simulated by the atmosphere-ocean general circulation models run in the second phase of PMIP result in a better agreement between models and data. Accounting for changes in interannual variability in the interpretation of the pollen data does not result in a reduction of the reconstructed cooling. The largest recent improvement in the model-data comparison has instead arisen from a new climate reconstruction based on inverse vegetation modelling, which explicitly accounts for the CO2 decrease at LGM and which substantially reduces the LGM winter cooling reconstructed from pollen assemblages. As a result, the simulated and observed LGM winter cooling over Western Europe and the Mediterranean area are now in much better agreement.

The impact of tidal dissipation changes on the Last Glacial Maximum AMOC

2020 ◽  
Author(s):  
Sophie-Berenice Wilmes ◽  
Mattias Green ◽  
Andreas Schmittner
Keyword(s):  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
Meridional Overturning Circulation ◽  
Tidal Mixing ◽  
Tidal Dissipation ◽  
Last Glacial ◽  
Meridional Overturning ◽  
The Impact ◽  
The Last Glacial Maximum ◽  
The Last Glacial

<p>The global mean sea-level decrease of 120 – 130 m during the Last Glacial Maximum (LGM; 26 – 19 kyr BP) is thought to have substantially altered semidiurnal tidal dynamics in the glacial North Atlantic. This more than doubled global open ocean tidal dissipation in comparison to present day and increased the amount of energy available for diapycnal mixing which is important for driving the global meridional overturning circulation. Reconstructions of the glacial ocean have generally suggested a more sluggish Atlantic meridional overturning circulation (AMOC) during the LGM together with weaker mixing. Here, we investigate the impact of tidal dissipation changes on the LGM AMOC and the carbon cycle using the intermediate complexity ocean model UVic coupled to the biogeochemistry model MOBI forced with three different LGM dissipation estimates. The simulations are constrained with LGM δ<sup>13</sup>C and radiocarbon data from sediments. Our results suggest that our simulations, as previously inferred, most closely agree with a weakened LGM AMOC (8 – 9 Sv), and importantly, that the agreement is consistent with increased LGM tidal mixing. These results firstly imply that a weakened AMOC state can occur with stronger tidal mixing without hampering the agreement with the sediment isotope data. Secondly, this work highlights the importance of considering tidal dissipation changes when modelling the paleo-ocean.</p>

scholarly journals Supplemental Material: Climate of the Last Glacial Maximum on the western Olympic Peninsula based on insect paleoecology

2020 ◽  
Author(s):  
Allan Ashworth ◽  
et al.
Keyword(s):  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
Fossil Insects ◽  
Climate Data ◽  
Model Data ◽  
Olympic Peninsula ◽  
Last Glacial ◽  
Fossil Insect ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Age-depth model data, images of fossil insect and plant macroscopic remains, lists of skeletal elements for fossil insects, and locality and derived climate data for Olophrum boreale and Olophrum consimile<br>

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