A 420,000 year deuterium excess record from East Antarctica: Information on past changes in the origin of precipitation at Vostok
Article first published online: 21 SEP 2012
Copyright 2001 by the American Geophysical Union.
Journal of Geophysical Research: Atmospheres (1984–2012)
Volume 106, Issue D23, pages 31863–31873, 16 December 2001
How to Cite
2001), A 420,000 year deuterium excess record from East Antarctica: Information on past changes in the origin of precipitation at Vostok, J. Geophys. Res., 106(D23), 31863–31873, doi:10.1029/2001JD900076., , , , , and (
- Issue published online: 21 SEP 2012
- Article first published online: 21 SEP 2012
- Manuscript Accepted: 26 JAN 2001
- Manuscript Received: 17 JUL 2000
Here we present and analyze the complete Vostok ice cores deuterium excess record which spans the last four climatic cycles, back to ∼420,000 years B.P. To extract paleoclimate information from this record, we use isotopic modeling showing that changes in deuterium excess (d = δD-8δ18O) of Vostok precipitation reflect changes in the average temperature of oceanic moisture sources. Over the last 250,000 years the deuterium excess is strongly anticorrelated with changes in Earth's obliquity. This reflects changes in the relative contribution of low and high latitudes to the Vostok precipitation, resulting from changes in the latitudinal annual mean insolation gradient governed by the obliquity. However, this modulation by obliquity is not observed prior to 250,000 years B.P. We attribute this difference to the ice flow, the deeper ice under Vostok station having accumulated in a location upstream Vostok, receiving precipitation from different oceanic origins. Despite this difference between the earlier and the later portions of the record, the deuterium excess changes during all the glacial inceptions are similar in amplitude and timing relative to the deuterium decrease. The glacial inceptions are characterized by high deuterium excess, indicating the significant role of the tropics in supplying moisture to the already cold poles.