GEOPHYSICAL RESEARCH LETTERS, VOL. 29, NO. 2, 10.1029/2001GL013781, 2002

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

Hezi Gildor1

Department of Environmental Sciences, Weizmann Institute of Science,
Israel

Michael Ghil

Department of Atmospheric Sciences and Institute of Geophysics and Planetary Physics, UCLA,
USA

[1]   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 CO2 and temperature can be opposite during different seasons and, moreover, that the phase relation can change during different 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 CO2 behind temperature upon entering a stadial, given reasonable assumptions about the precipitation-weighted temperature record at Vostok.

Received 16 July 2001; revised 19 October 2001; accepted 12 November 2001; published 26 January 2002.

Index Terms: 3344 Meteorology and Atmospheric Dynamics: Paleoclimatology.


AGU

Citation: Gildor, H., and M. Ghil, Phase relations between climate proxy records: Potential effect of seasonal precipitation changes, Geophys. Res. Lett., 29(2), 10.1029/2001GL013781, 2002.