A Short Circuit in Thermohaline Circulation: A Cause for Northern Hemisphere Glaciation?

The cause of Northern Hemisphere glaciation about 3 million years ago remains uncertain. Closing the Panamanian Isthmus increased thermohaline circulation and enhanced moisture supply to high latitudes, but the accompanying heat would have inhibited ice growth. One possible solution is that enhanced...

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Bibliographic Details
Published in:Science
Main Authors: Driscoll, N. W., Haug, G. H.
Format: Article in Journal/Newspaper
Language:English
Published: American Association for the Advancement of Science (AAAS) 1998
Subjects:
Online Access:http://dx.doi.org/10.1126/science.282.5388.436
https://www.science.org/doi/pdf/10.1126/science.282.5388.436
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Summary:The cause of Northern Hemisphere glaciation about 3 million years ago remains uncertain. Closing the Panamanian Isthmus increased thermohaline circulation and enhanced moisture supply to high latitudes, but the accompanying heat would have inhibited ice growth. One possible solution is that enhanced moisture transported to Eurasia also enhanced freshwater delivery to the Arctic via Siberian rivers. Freshwater input to the Arctic would facilitate sea ice formation, increase the albedo, and isolate the high heat capacity of the ocean from the atmosphere. It would also act as a negative feedback on the efficiency of the “conveyor belt” heat pump.