Paleogeographic controls on the onset of the Antarctic circumpolar current
Paleogeographic controls on the onset of the Antarctic circumpolar current
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DOI：
10.1002/grl.50941
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发表时间：
2013-10-16
影响因子：
5.2
通讯作者：
Bowman, Vanessa C.
中科院分区：
文献类型：
--
作者：
Hill, Daniel J.;Haywood, Alan M.;Bowman, Vanessa C.
南极环极流（ACC）在新生代的发展在时间及其在主要气候转变中的作用方面存在争议。有些人认为，南极冰川带的发展有助于南极洲大陆尺度的冰川作用和始新世/渐新世边界的气候变冷。在这里，我们提出的气候模式结果表明，尽管通过德雷克海峡和塔斯曼门户的深水连接以及南极冰川的开始，由于澳大利亚古地理的原因，渐新世期间不可能出现连贯的ACC。洋流模拟与渐新世物理海洋学的古环境记录相比较，为理解明显矛盾的ACC起源年代提供了一个框架。我们认为，澳大拉西亚陆块的北移以及塔斯曼海道和德雷克通道的重新配置是形成一个强的、连贯的ACC的必要前提。
Development of the Antarctic Circumpolar Current (ACC) during the Cenozoic is controversial in terms of timing and its role in major climate transitions. Some propose that the development of the ACC was instrumental in the continental scale glaciation of Antarctica and climate cooling at the Eocene/Oligocene boundary. Here we present climate model results that show that a coherent ACC was not possible during the Oligocene due to Australasian paleogeography, despite deep water connections through the Drake Passage and Tasman Gateway and the initiation of Antarctic glaciation. The simulations of ocean currents compare well to paleoenvironmental records relating to the physical oceanography of the Oligocene and provide a framework for understanding apparently contradictory dating of the initiation of the ACC. We conclude that the northward motion of the Australasian land masses and the reconfiguration of the Tasman Seaway and Drake Passage are necessary preconditions for the formation of a strong, coherent ACC.