GRIP Deuterium Excess Reveals Rapid and Orbital-Scale Changes in Greenland Moisture Origin

Department of Geological Sciences, University of Colorado at Boulder, Boulder, Colorado, United States
Science (Impact Factor: 33.61). 08/2005; 309(5731):118-21. DOI: 10.1126/science.1108575
Source: PubMed


The Northern Hemisphere hydrological cycle is a key factor coupling ice sheets, ocean circulation, and polar amplification of climate change. Here we present a Northern Hemisphere deuterium excess profile covering one climatic cycle, constructed with the use of delta18O and deltaD Greenland Ice Core Project (GRIP) records. Past changes in Greenland source and site temperatures are quantified with precipitation seasonality taken into account. The imprint of obliquity is evidenced in the site-to-source temperature gradient at orbital scale. At the millennial time scale, GRIP source temperature changes reflect southward shifts of the geographical locations of moisture sources during cold events, and these rapid shifts are associated with large-scale changes in atmospheric circulation.

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    • "The enhancement of the source–site temperature gradient enhances isotopic distillation and produces precipitation with lower δ 18 O levels during cold periods, increasing α. Contradicting earlier assumptions (Boyle, 1997), conceptual distillation models constrained by GRIP deuterium excess data suggest that this effect is most probably secondary (Masson-Delmotte et al., 2005). "
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