Glaciochemical evidence in an East Antarctica ice core of a recent (AD 1450–1850) neoglacial episode
Glaciochemical evidence in an East Antarctica ice core of a recent (AD 1450–1850) neoglacial episode
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DOI：
10.1029/2008jd011091
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发表时间：
2008-12
影响因子：
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通讯作者：
Yuansheng Li;J. Cole‐Dai;Liya Zhou
中科院分区：
文献类型：
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作者：
Yuansheng Li;J. Cole‐Dai;Liya Zhou
[1] 对东南极洲伊丽莎白公主地基本上未勘探区域的一个位置 (DT263) 的浅层 (82.5 m) 冰芯进行化学分析，已用于构建连续、高分辨率的 780 年 (AD 1207-1996) 冰川化学记录。二十世纪期间，积雪速率和雪中化学物质浓度似乎稳定且存在短期变化，表明气候条件相对稳定和温暖。该记录中公元 1450 年至 1850 年期间的特点是积雪速率急剧下降，并且几种化学物质的浓度降低，这些化学物质因积雪速率极低而遭受沉积后损失。这些特征与较冷的气候条件一致，表明这可能是一次新冰期事件。这一集的时间恰逢小冰河时期（LIA），这是十五世纪初至十九世纪末北半球相对寒冷的时期。冰芯和沉积记录中的证据也表明，在 LIA 的一般时间范围内，南半球一些地点的新冰川条件。 DT263 记录以及一些已发表的冰芯记录表明，15 世纪至 20 世纪期间南极洲存在 LIA 型气候事件。然而，其他南极冰芯记录没有显示这样的证据。这些记录共同凸显了南极洲全新世气候变化的区域差异。 DT263 记录表明，LIA 期间，东南极洲印度洋东部地区普遍存在寒冷和干燥的气候。
[1] Chemical analysis of a shallow (82.5 m) ice core from a location (DT263) in the essentially unexplored area of Princess Elizabeth Land, East Antarctica, has been used to construct a continuous, high-resolution 780-year (AD 1207–1996) glaciochemical record. During the twentieth century, snow accumulation rates and concentrations of chemical species in snow appear to be stable with short-term variations, indicating relatively stable and warm climatic conditions. The period of AD 1450–1850 in this record is characterized by sharply reduced snow accumulation rates and decreased concentrations of several chemical species that suffer postdepositional losses linked to very low accumulation rates. These characteristics are consistent with colder climatic conditions and suggest that this is likely a neoglacial episode. The timing of this episode coincides with the Little Ice Age (LIA), a relatively cold period in the Northern Hemisphere between the beginning of the fifteenth century and the end of the nineteenth century. Evidence in ice core and sedimentary records also indicates neoglacial conditions in some Southern Hemisphere locations during the general time frame of LIA. The DT263 record, along with a few published ice core records, points to the existence of an LIA-type climatic episode in Antarctica between the fifteenth century and the twentieth century. However, other Antarctic ice core records show no such evidence. Together, these records highlight the regional differences in Holocene climate variations in Antarctica. The DT263 record suggests that colder and drier conditions prevailed during the LIA time period at the eastern Indian Ocean sector of East Antarctica.