Phase relations between climate proxy records: Potential effect of seasonal precipitation changes

Phase relations between climate variables are critical in order to ascertain the main mechanisms driving glaciation cycles. Proxy records from ice cores are commonly assumed to represent annual mean averages. These averages, however, may be biased toward a particular season due, for example, to a ch...

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Bibliographic Details
Main Authors: Hezi Gildor, Michael Ghil
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Subjects:
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.22.6605
http://www.atmos.ucla.edu/tcd/PREPRINTS/GGText.pdf
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Summary:Phase relations between climate variables are critical in order to ascertain the main mechanisms driving glaciation cycles. Proxy records from ice cores are commonly assumed to represent annual mean averages. These averages, however, may be biased toward a particular season due, for example, to a change in the distribution of precipitation. We demonstrate using a nine-box model of the climate system that the phase relation between atmospheric CO 2 and temperature can be opposite during di#erent seasons and, moreover, that the phase relation can change during di#erent stages of the glacial cycle. Ice-core records may thus favor one phase relation during certain stages over another. Our model can explain the observed lag of several thousand years of atmospheric CO 2 behind temperature upon entering a stadial, given reasonable assumptions about the precipitation-weighted temperature record at Vostok.