Different trends in Antarctic temperature and atmospheric CO 2 during the last glacial
We analyze the past 67,000years of climate using Antarctic ice-core records to constrain the mechanisms involved in (a) the bipolar seesaw relationship between Greenland and Antarctic surface temperature variations, and (b) mechanisms of millennial-scale atmospheric CO 2 concentration variations. Sp...
Published in: | Geophysical Research Letters |
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Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Amer Geophysical Union
2021
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Subjects: | |
Online Access: | https://doi.org/10.1029/2021GL093868 http://ecite.utas.edu.au/151696 |
Summary: | We analyze the past 67,000years of climate using Antarctic ice-core records to constrain the mechanisms involved in (a) the bipolar seesaw relationship between Greenland and Antarctic surface temperature variations, and (b) mechanisms of millennial-scale atmospheric CO 2 concentration variations. Specifically, we determine for each Greenland Stadial the rate of Antarctic temperature and atmospheric CO 2 rise. We find that Antarctic warming rates significantly decrease as the climate cools during the glacial period, whereas the rate of atmospheric CO 2 rise does not significantly change. Also, we find that the rates of Antarctic warming and atmospheric CO 2 rise are both insensitive to whether a given stadial contains a Heinrich event. These results challenge the view that a single Southern-Ocean-based mechanism dominates the observed glacial variability in Antarctic temperature and atmospheric CO 2 . Instead, our results are consistent with an important contribution of low- and mid-latitude processes to millennial-scale atmospheric CO 2 changes. |
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