Early Eocene arctic climate sensitivity to pCO₂ and basin geography

We present results from new early Eocene (∼55-45 Ma) 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...

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Bibliographic Details
Published in:Geophysical Research Letters
Other Authors: Shellito, Cindy (author), Lamarque, Jean-François (author), Sloan, Lisa (author)
Format: Article in Journal/Newspaper
Language:English
Published: American Geophysical Union 2009
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Online Access:http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-002-226
https://doi.org/10.1029/2009GL037248
Description
Summary:We present results from new early Eocene (∼55-45 Ma) 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 ∼8°C 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 ∼4°C.