Evolution of Ocean Temperature and Ice Volume Through the Mid-Pleistocene Climate Transition
Evolution of Ocean Temperature and Ice Volume Through the Mid-Pleistocene Climate Transition
复制标题
DOI：
10.1126/science.1221294
复制
发表时间：
2012-08-10
期刊：
影响因子：
56.9
通讯作者：
Piotrowski, A. M.
中科院分区：
文献类型：
--
作者：
Elderfield, H.;Ferretti, P.;Piotrowski, A. M.
地球气候在 1250 年前到 70 万年前，即更新世中期过渡 (MPT) 期间经历了根本性的变化，在轨道强迫没有发生实质性变化的情况下，气候周期的主要周期从 4.1 万年变为 10 万年。在此期间，深海有孔虫氧同位素比率的变化幅度出现增加，传统上将其解释为定义冰河时代的主要节奏，尽管深海温度变化的影响很大。我们已经区分了温度降低和全球冰量增加对氧同位素比的影响。我们的结果表明，MPT 是由 90 万年前南极冰量突然增加引发的。我们没有看到逐渐变冷模式的证据，但每个盛冰期都会出现接近冰点的温度。
Earth's climate underwent a fundamental change between 1250 and 700 thousand years ago, the mid-Pleistocene transition (MPT), when the dominant periodicity of climate cycles changed from 41 thousand to 100 thousand years in the absence of substantial change in orbital forcing. Over this time, an increase occurred in the amplitude of change of deep-ocean foraminiferal oxygen isotopic ratios, traditionally interpreted as defining the main rhythm of ice ages although containing large effects of changes in deep-ocean temperature. We have separated the effects of decreasing temperature and increasing global ice volume on oxygen isotope ratios. Our results suggest that the MPT was initiated by an abrupt increase in Antarctic ice volume 900 thousand years ago. We see no evidence of a pattern of gradual cooling, but near-freezing temperatures occur at every glacial maximum.