Temperature and precipitation history of the Arctic

G. H. Miller, J. Brigham-Grette, R. B. Alley, L. Anderson, H. A. Bauch, M. S. Douglas, M. E. Edwards, S. A. Elias, B. P. Finney, J. J. Fitzpatrick, S. V. Funder, T. D. Herbert, L. D. Hinzman, D. S. Kaufman, G. M. MacDonald, L. Polyak, A. Robock, M. C. Serreze, J. P. Smol, R. Spielhagen, J. W. White, A. P. Wolfe, and E. W. Wolff

Quaternary Science Reviews (2010)

DOI: 10.1016/j.quascirev.2010.03.001

As the planet cooled from peak warmth in the early Cenozoic, extensive Northern Hemisphere ice sheets developed by 2.6 Ma ago, leading to changes in the circulation of both the atmosphere and oceans. From ∼2.6 to ∼1.0 Ma ago, ice sheets came and went about every 41 ka, in pace with cycles in the tilt of Earth’s axis, but for the past 700 ka, glacial cycles have been longer, lasting ∼100 ka, separated by brief, warm interglaciations, when sea level and ice volumes were close to present. The cause of the shift from 41 ka to 100 ka glacial cycles is still debated. During the penultimate interglaciation, ∼130 to ∼120 ka ago, solar energy in summer in the Arctic was greater than at any time subsequently. As a consequence, Arctic summers were ∼5 °C warmer than at present, and almost all glaciers melted completely except for the Greenland Ice Sheet, and even it was reduced in size substantially from its present extent. With the loss of land ice, sea level was about 5 m higher than present, with the extra melt coming from both Greenland and Antarctica as well as small glaciers. The Last Glacial Maximum (LGM) peaked ∼21 ka ago, when mean annual temperatures over parts of the Arctic were as much as 20 °C lower than at present. Ice recession was well underway 16 ka ago, and most of the Northern Hemisphere ice sheets had melted by 6 ka ago. Solar energy reached a summer maximum (9

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