Early Eocene Arctic climate sensitivity to pCO2 and basin geography

[1] We present results from new early Eocene (55–45Ma) climate modeling experiments with the NCAR Community Climate System Model. These experiments test the sensitivity of climate to a large increase in atmospheric greenhouse gases, such as may have occurred at the Paleocene-Eocene (P-E) boundary (5...

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Bibliographic Details
Main Author: Cindy J. Shellito Jean-françois Lamarque
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Subjects:
36
doi
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.664.4448
http://acd.ucar.edu/%7Elamar/PDF/2009GL037248.pdf
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Summary:[1] We present results from new early Eocene (55–45Ma) climate modeling experiments with the NCAR Community Climate System Model. These experiments test the sensitivity of climate to a large increase in atmospheric greenhouse gases, such as may have occurred at the Paleocene-Eocene (P-E) boundary (55.5 Ma), and also allow us to explore the role of Arctic basin configuration on climate. Experiments were run with pCO2 at 560 and 2240 ppm, and a third experiment, at 2240 ppm, incorporates a passage to a neighboring ocean to explore the potential effect of the ocean on Arctic warming, were the Arctic not isolated. Quadrupling pCO2 warms the Arctic by 8C in the annual average, doubles atmospheric moisture content in this region and eliminates Arctic sea ice, consistent with proxy estimates of warming at the P-E boundary. Opening the Arctic Ocean warms mean annual sea surface temperature by an additional 4C.