Stratigraphic correlations between the European Project for Ice Coring in Antarctica (EPICA) Dome C and Vostok ice cores showing the relative variations of snow accumulation over the past 45 kyr
Stratigraphic correlations between the European Project for Ice Coring in Antarctica (EPICA) Dome C and Vostok ice cores showing the relative variations of snow accumulation over the past 45 kyr
复制标题
欧洲南极洲冰芯项目 (EPICA) Dome C 和 Vostok 冰芯之间的地层相关性显示了过去 45 公里积雪的相对变化
DOI：
10.1029/2003jd004180
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发表时间：
2004
影响因子：
--
通讯作者：
E. Wolff
中科院分区：
文献类型：
--
作者：
R. Udisti;S. Becagli;E. Castellano;B. Delmonte;J. Jouzel;J. Petit;J. Schwander;B. Stenni;E. Wolff
[1]对两个冰芯记录（欧洲南极洲冰芯项目（EPICA）Dome C和Bostok）进行的高分辨率化学分析和电学测量跨越了过去45 kyr，通过匹配火山事件进行了地层相关性。根据雪层中的酸度和硫酸盐峰值，沿着两个冰芯确定了几个常见事件。通过与同位素（δD）剖面的比较，并使用南极冷逆转（ACR）最小值，10 Be峰值和尘埃尖峰作为时间检查点，时间尺度相匹配。在这两个网站在全新世，在冰川-间冰期过渡和冰期的最后一部分，相对积雪的比例重建找到最适合的圆顶C和东方深度记录相同的事件。在考虑了埋藏在冰川内的地层变薄后，冰穹C-东方号的积累比（根据传统的积累温度同位素方法，预计大致恒定）在冰期为1.12，但在全新世的大部分时间里增加到1.44。冰川效应主要与东方冰沿着海岭B-东方轴的地理起源有关，只能解释这种变化的一小部分。相反，我们认为，积累的核心之间的变化源于在这两个站点在这些各自的气候时期在大气环流的差异变化。区域变化的大气环流提出了一个负异常在圆顶C，一个积极的积累异常在东方，或两者的组合在冰川气候。我们的方法可能有助于改进冰芯测年：（1）揭示基于经典热力学方法的累积速率估计的异常;（2）支持考虑大气环流过程变化的贡献的必要性。
[1] High-resolution chemistry analysis and electrical measurements performed on two ice core records (European Project for Ice Coring in Antarctica (EPICA) Dome C and Vostok) spanning the last 45 kyr allow stratigraphic correlations by matching volcanic events. Several common events were identified along the two ice cores on the basis of acidity and sulphate spikes in snow layers. Timescales were matched through comparison with isotope (δD) profiles and using the Antarctic cold reversal (ACR) minimum, a 10Be peak, and a dust spike as temporal checkpoints. Ratios of relative snow accumulation at the two sites during the Holocene, in the glacial-interglacial transition and in the last part of the glacial period, were reconstructed by finding the best fit between Dome C and Vostok depths recording the same events. After accounting for thinning of the layers as they are buried within the glacier, the Dome C-Vostok accumulation ratio, expected to be roughly constant from the conventional accumulation-temperature-isotope approach, is 1.12 for the glacial period but increases to as much as 1.44 for a large part of the Holocene. Glaciological effects, mainly related to the geographic origin of the Vostok ice along the Ridge B-Vostok axis, can account for only a minor fraction of this change. Instead, we argue that accumulation variability between the cores stems from differential changes in atmospheric circulation during these respective climatic periods at the two sites. Regional changes in atmospheric circulation are proposed with a negative anomaly in Dome C, a positive accumulation anomaly in Vostok, or a combination of both during glacial climate. Our approach may help to improve ice core dating by: (1) revealing anomalies in accumulation-rate estimation based on the classical thermodynamic method and (2) supporting the necessity to take into account contributions due to changes in atmospheric circulation processes.