scholarly journals Glaciation and deglaciation mechanisms in a coupled two-dimensional climate—ice-sheet model

1993 ◽  
Vol 39 (131) ◽  
pp. 45-49 ◽  
Author(s):  
André Berger ◽  
Hubert Gallée ◽  
Christian Tricot
Keyword(s):  
Ice Core ◽  
Ice Sheets ◽  
Low Frequency ◽  
Two Dimensional ◽  
Atmospheric Concentration ◽  
Last Glacial ◽  
Simulated Climate ◽  
Milankovitch Theory ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Abstract A two-dimensional model which links the atmosphere, the mixed layer of the ocean, the sea ice, the continents, the ice sheets and their underlying bedrock has been used to test the Milankovitch theory over the last glacial—interglacial cycle. It was found that the orbital variations alone can induce, in such a system, feed-backs sufficient to generate the low-frequency part of the climatic variations over the last 122 kyear. These simulated variations at the astronomical time-scale are broadly in agreement with ice volume and sea-level reconstructions independently obtained from geological data. Imperfections in the simulated climate were the insufficient southward extent of the ice sheets and the too small hemispheric cooling during the last glacial maximum. These deficiencies were partly remedied in a further experiment (Gallée and others, in press) by using the time-dependent CO2 atmospheric concentration given by the Vostok ice core in addition to the astronomical forcing. For this second experiment, the main mechanisms and feedbacks responsible for the glaciation and the deglaciation in the model are discussed here.

scholarly journals Milankovitch Theory and climate

1988 ◽  
Vol 26 (4) ◽  
pp. 624-657 ◽  
Author(s):  
A. Berger
Keyword(s):  
Milankovitch Theory

Milankovitch theory viewed from Devils Hole

Nature ◽  
1993 ◽  
Vol 363 (6429) ◽  
pp. 531-533 ◽  
Author(s):  
J. Imbrie ◽  
A. C. Mix ◽  
D. G. Martinson
Keyword(s):  
Devils Hole ◽  
Milankovitch Theory

Statistical Analysis of Grain Size Distribution in Pleistocene Sediments from Lake Biwa, Japan

1988 ◽  
Vol 30 (1) ◽  
pp. 12-18 ◽  
Author(s):  
Kenji Kashiwaya ◽  
Atsuyuki Yamamoto ◽  
Kaoru Fukuyama
Keyword(s):  
Time Series ◽  
Grain Size ◽  
Statistical Analysis ◽  
Size Distribution ◽  
Lake Biwa ◽  
Size Distributions ◽  
Solar Insolation ◽  
The Past ◽  
Grain Size Distributions ◽  
Milankovitch Theory

Time series of grain-size distributions from Pleistocene sediments deposited in Lake Biwa during the past 550 millennia show dominant periods of 40,000 and 20,000 yr that are very close to those predicted by the Milankovitch theory, as well as a period of about 70,000 yr not directly predicted by this theory. The 70,000-yr period is strongest, followed by the 20,000-yr period. The sequences also show that coarser particles were deposited, in general, during strong solar insolation, whereas finer particles were deposited during weak insolation.

Periodic Variations in Late Pleistocene Speleothem Abundance in Britain

1991 ◽  
Vol 35 (2) ◽  
pp. 190-196 ◽  
Author(s):  
Kenji Kashiwaya ◽  
Timothy C. Atkinson ◽  
Peter L. Smart
Keyword(s):  
United Kingdom ◽  
Late Pleistocene ◽  
Temporal Change ◽  
The Past ◽  
The United Kingdom ◽  
Last Glaciation ◽  
Milankovitch Theory

AbstractTemporal change in the growth of speleothems in the United Kingdom during the past 150,000 years is shown to be related to the insolation variation by the Milankovitch theory. The speleothem data compiled by Gordon et al. (1989. Quarternary Research 31, 14–26) have two Milanokovitch frequencies: the ca. 40,000-yr period related to change in the earth's obliquity and the ca. 20,000-yr period related to the precession of the equinoxes. The abundance of speleothem growth was, in general, large during the last interglaciation and small during the last glaciation. In both periods, however, speleothem abundance was greater during periods of strong insolation and less during weak insolation.

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