Northern Hemisphere forcing of climatic cycles in Antarctica over the past 360,000 years
Northern Hemisphere forcing of climatic cycles in Antarctica over the past 360,000 years
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DOI：
10.1038/nature06015
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发表时间：
2007-08-23
期刊：
影响因子：
64.8
通讯作者：
Watanabe, Okitsugu
中科院分区：
文献类型：
--
作者：
Kawamura, Kenji;Parrenin, Frederic;Watanabe, Okitsugu
米兰科维奇的气候变化理论提出，冰期间冰期循环是由北方高纬度地区夏季日照变化驱动的（1）。南半球在冰期-间冰期过渡期（即所谓的终止期）气候变化的时间相对于北方半球夏季日照的变化是对这一假设的一个重要检验。到目前为止，只能将此测试应用于最近的终止（2，3），因为与较早终止相关的日期不确定性太大，无法确定相位关系。在这里，我们提出了一个新的年表南极气候变化在过去的360，000年，是基于氧氮分子的比例在空气中被困在圆顶富士和东方冰芯（4，5）。这个比率是当地夏季日照的代表（5），因此可以通过轨道调整来构建年表，而无需假设气候记录和轨道参数之间的滞后。年表的准确性使我们能够检查冰芯（6-9）的气候记录与日照变化之间的相位关系。我们的研究结果表明，轨道尺度的南极气候变化滞后于北方半球太阳辐射几千年，南极温度和大气二氧化碳浓度的增加，在过去的四个终端发生在上升阶段的北方半球夏季太阳辐射。这些结果支持了Milankovitch的理论，即北方夏季日照引发了最后四次冰川消退（3，10，11）。
The Milankovitch theory of climate change proposes that glacial interglacial cycles are driven by changes in summer insolation at high northern latitudes(1). The timing of climate change in the Southern Hemisphere at glacial-interglacial transitions (which are known as terminations) relative to variations in summer insolation in the Northern Hemisphere is an important test of this hypothesis. So far, it has only been possible to apply this test to the most recent termination(2,3), because the dating uncertainty associated with older terminations is too large to allow phase relationships to be determined. Here we present a new chronology of Antarctic climate change over the past 360,000 years that is based on the ratio of oxygen to nitrogen molecules in air trapped in the Dome Fuji and Vostok ice cores(4,5). This ratio is a proxy for local summer insolation(5), and thus allows the chronology to be constructed by orbital tuning without the need to assume a lag between a climate record and an orbital parameter. The accuracy of the chronology allows us to examine the phase relationships between climate records from the ice cores(6-9) and changes in insolation. Our results indicate that orbital-scale Antarctic climate change lags Northern Hemisphere insolation by a few millennia, and that the increases in Antarctic temperature and atmospheric carbon dioxide concentration during the last four terminations occurred within the rising phase of Northern Hemisphere summer insolation. These results support the Milankovitch theory that Northern Hemisphere summer insolation triggered the last four deglaciations(3,10,11).