Climate since AD 1510 on Dyer Plateau, Antarctic Peninsula: evidence for recent climate change

Author： Thompson L.G. Peel D.A. Mosley-Thompson E Mulvaney R Dal J Lin P.N. Davis M.E. Raymond C.F.

Publisher： International Glaciological Society

ISSN： 1727-5644

Source： Annals of Glaciology, Vol.20, Iss.1, 1994-06, pp. : 420-426

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Abstract

A 480 year record of the oxygen-isotope ratios, dust content, chemical spccies and net accumulation from ice cores drilled in 1989 90 on Dyer Plateau in the Antarctic Peninsula is presented. The continuous analyses of small (sub-annual) samples reveal well-preserved annual variations in both sulfate contcnt and δ¹⁸O, thus allowing an excellent time-scale to be established. This history reveals a recent pronounced warming in which the last two decades have been among the warmest in the last five centuries. Furthermore, unlike in East Antarctica, on Dycr Plateau conditions appear to have been fairly normal from AD1500 to 1850 with cooler conditions from 1850 to 1930 and a warming trend dominating since 1930. Reconstructed annual layer thicknesses suggest an increase in net accumulation beginning early in the 19th century and continuing to the present. This intuitive conflict between increasing net accumulation and depleted δ¹⁸ O (cooler climate) in the 19th century appears widespread in the peninsula region and challengcs our understanding of the physical relationships among moisture sources, air temperatures and snow accumulation. The complex meteorological regime in the Antarctic Peninsula region complicates meaningful interpretation of proxy indicators and results in a strong imprint of local high-frequency processes upon the larger-scale climate picture.