[Research Article] Annually Resolved Ice Core Records of Tropical Climate Variability Over the Past ~1800 Years

L. G. Thompson1,2,*, E. Mosley-Thompson1,3, M. E. Davis1, V. S. Zagorodnov1, I. M. Howat1,2, V. N. Mikhalenko4, P.-N. Lin1

1Byrd Polar Research Center, The Ohio State University, Columbus, OH 43210, USA.

2School of Earth Sciences, The Ohio State University, Columbus, OH 43210, USA.

3Department of Geography, The Ohio State University, Columbus, OH 43210, USA.

4Institute of Geography, Russian Academy of Sciences, Moscow, Russia. ?*Corresponding author. E-mail: thompson.3{at}osu.eduIce cores from low latitudes can provide a wealth of unique information about past climate in the tropics, but they are difficult to recover and few exist. Here, we report annually resolved ice core records from the Quelccaya ice cap (5670 masl) in Peru which extend back ~1800 years and provide a high-resolution record of climate variability there. Oxygen isotopic ratios (d18O) are linked to sea-surface temperatures in the tropical eastern Pacific, while concentrations of ammonium and nitrate document the dominant role played by the migration of the Intertropical Convergence Zone in the region of the tropical Andes. Quelccaya continues to retreat and thin: Radiocarbon dates on wetland plants exposed along its retreating margins indicate it has not been smaller for at least six millennia.

Received for publication 18 December 2012. Accepted for publication 21 March 2013.

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