Effects of Arctic freshwater forcing on thermohaline circulation during the Pleistocene
Effects of Arctic freshwater forcing on thermohaline circulation during the Pleistocene
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DOI：
10.1130/g23966a.1
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发表时间：
2007-12
期刊：
影响因子：
5.8
通讯作者：
J. Knies;J. Matthiessen;A. Mackensen;R. Stein;C. Vogt;T. Frederichs;S. Nam
中科院分区：
文献类型：
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作者：
J. Knies;J. Matthiessen;A. Mackensen;R. Stein;C. Vogt;T. Frederichs;S. Nam
在本文中，我们利用北冰洋-大西洋门户中的含碳酸钙沉积物序列来生成北冰洋的标准参考气候记录。我们提供了一份连续且日期明确的海洋沉积物记录，记录了过去 0.8 m.y 期间北极淡水脉冲对地球气候系统的强烈影响。浮游有孔虫氧和碳同位素数据显示，从环北极冰盖和冰坝湖泊崩塌中释放出来的淡水羽流在亚米兰科维奇时间尺度上被平流输送到北冰洋门户。鉴于从碳同位素数据推断出的北冰洋淡水脉冲与北大西洋深水形成强度的密切对应性，我们得出结论，北冰洋的淡水化对温盐环流的影响比之前认识的更为频繁。我们的数据表明，对于旨在揭示更新世气候强迫因素的大气-冰-海洋耦合模型来说，将北极淡水视为关键的强迫因素至关重要。
In this paper, we make use of calcium carbonate-bearing sediment sequences in the Arctic-Atlantic gateway to produce a standard reference climate record for the Arctic Ocean. We present a continuous and exceptionally well-dated marine sediment record documenting the strong imprint of Arctic freshwater pulses on Earth's climate system throughout the past 0.8 m.y. Planktic foraminiferal oxygen and carbon isotope data reveal that freshwater plumes released from collapsing circum-Arctic ice sheets and ice-dammed lakes were advected to the Arctic Ocean gateway on sub-Milankovitch time scales. Given the close correspondence of Arctic freshwater pulses and strength of North Atlantic Deep Water formation as inferred from carbon isotope data, we conclude that freshening of the Arctic Ocean influenced thermohaline circulation more frequently than previously recognized. Our data show that it is critical for coupled atmosphere-ice-ocean general circulation models aimed at unraveling climate forcing factors during the Pleistocene to consider Arctic freshwater as a crucial forcing factor.