Byrd Polar Research Center, The Ohio State University, Columbus, OH 43210, USA.
Science. 2013 May 24;340(6135):945-50. doi: 10.1126/science.1234210. Epub 2013 Apr 4.
Ice 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 meters above sea level) in Peru that extend back ~1800 years and provide a high-resolution record of climate variability there. Oxygen isotopic ratios (δ(18)O) are linked to sea surface temperatures in the tropical eastern Pacific, whereas 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 that it has not been smaller for at least six millennia.
低纬度的冰芯可以提供大量关于热带过去气候的独特信息，但它们很难被回收，而且数量很少。在这里，我们报告了来自秘鲁 Quelccaya 冰帽（海拔 5670 米）的每年分辨率的冰芯记录，该记录可追溯到~1800 年前，提供了该地区气候变率的高分辨率记录。氧同位素比值（δ（18）O）与热带东太平洋的海面温度有关，而铵和硝酸盐的浓度则记录了热带安第斯山脉地区热带辐合带迁移的主导作用。Quelccaya 仍在继续退缩和变薄。沿其退缩边缘暴露的湿地植物的放射性碳日期表明，它的规模至少在六千年前就没有更小了。
