Beryllium 10 in the Greenland Ice Core Project ice core at Summit, Greenland
Beryllium 10 in the Greenland Ice Core Project ice core at Summit, Greenland
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DOI：
10.1029/97jc01265
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发表时间：
1997-11-30
影响因子：
3.6
通讯作者：
Yiou, P
中科院分区：
文献类型：
--
作者：
Yiou, F;Raisbeck, GM;Yiou, P
在格陵兰岛顶峰钻探的格陵兰冰芯项目(GRIP)冰芯中，测量了1350多个样品中宇宙成因同位素Be-10的浓度。尽管0.45微米滤清器保留在部分样品中的Be-10中的尘埃成分使解释变得复杂，但结果证实Be-10浓度变化的一级来源是不同气候条件下降水速率的变化。这种影响不仅出现在冰期和间冰期之间，而且还出现在较短的“丹斯加德-奥施格”间歇期。相比之下，BE-10数据不支持对上一次间冰期快速变化的积累(即气候)的解释。然而，在这些事件中，它们可以用来帮助限制冰的来源。在考虑了可变的积雪效应后，观测到了Be-10通量的变化，这可能是由太阳和地磁调制引起的，但也可能是由初级宇宙线的变化引起的。最引人注目的是一个类似于40,000年前的BE-10峰值，类似于在沃斯托克冰芯中发现的峰值，从而使北极和南极冰芯的气候记录之间能够非常精确地关联。Cl-36/Be-10比值(考虑总的或仅与冰有关的Be-10)在整个岩心深度上显示出显著的变化，从而证实了使用该参数来确定冰芯的年龄是困难的。
Concentrations of the cosmogenic isotope Be-10 have been measured in more than 1350 samples from the Greenland Ice Core Project (GRIP) ice core drilled at Summit, Greenland. Although a dust-associated component of Be-10 retained by 0.45 mu m filters in some of the samples complicates the interpretations, the results confirm that the first-order origin of Be-10 concentration variations is changes in precipitation rate associated with different climate regimes. This effect is seen not only between glacial and interglacial periods, but also during the shorter ''Dansgaard-Oeschger'' interstadials. By contrast, the Be-10 data do not support the interpretation of rapidly varying accumulation (i.e., climate) during the last interglacial. They can, however, be used to help place limits on the origin of the ice in these events. After taking into account variable snow accumulation effects, variations in the Be-10 flux are observed, probably caused by solar and geomagnetic modulation, but possibly also by primary cosmic ray variations. The most dramatic is a Be-10 peak similar to 40,000 years ago, similar to that found in the Vostok ice core, thus permitting a very precise correlation between climate records from Arctic and Antarctic ice cores. The Cl-36/Be-10 ratio (considering either ''total'' or only ice-associated Be-10) shows significant variability over the whole core depth, thus confirming the difficulty in using this parameter for ''dating'' ice cores.