Modeling the Glacial Evolution of Antarctica and the Paleogene Transition from a "Greenhouse" to "Icehouse" World

东南极洲的冰川作用和与之相关的南半球高纬度地区向寒冷状态的转变，代表着新生代全球气候-海洋系统最根本的重组。确定南极冰盖成核、发育和周期性波动的机制对于我们理解全球气候系统和未来气候变化具有重要意义。从始新世早期温暖的“温室”气候模式到今天的“冰屋”气候模式，新生代的降温趋势早已被古生物学、同位素和沉积学证据所确认。该奖项旨在回答以下问题：1)是什么长期的古环境变化导致了始新世中晚期南极有限冰盖的增长；2)是什么触发了东南极冰盖在渐新世早期(-33.7 Ma)的快速增长。一项关于始新世晚期/渐新世早期气候回响的全面调查，旨在分离可能的气候强迫机制和反馈在从“温室”到“冰室”世界的转变中的相对作用，将使用Genesis 2.0版全球气候模式，其相互作用与预测植被模式(IBIS)相耦合，并与专门为全球气候机制关于冰盖形成和发展的研究而设计的新的高分辨率动态冰盖模式相耦合。一系列系统的敏感性测试将评估大气二氧化碳、轨道参数、大气-植被反馈、古地理和海洋热传输在南极洲冰川形成和增长中的作用。

The glaciation of East Antarctica and the associated shift to cold condition over high southern latitudes represents the most fundamental reorganization of the global climate-ocean system in the Cenozoic. Determining the mechanisms responsible for the nucleation, development, and periodic fluctuations of the Antarctic ice sheet is important to our understanding of the global climate system and future climatic change. The Cenozoic cooling trend from the warm "greenhouse" climate mode of the Early Eocene, to the "ice house" world of today, has long been recognized in paleontologic, isotopic, and sedimentologic evidence. This award supports designed to answer these question: 1) what long-term paleoenvironmental changes led to the growth of limited Antarctic ice during the mid-Late Eocene and 2) what triggered the rapid growth of the East Antarctic ice sheet in the earliest Oligocene (-33.7 ma). A comprehensive investigation of Late Eocene/Early Oligocene climate echoing, designed to isolate the relative role of possible climate forcing mechanisms and feedbacks in the transition from a "greenhouse" to "icehouse" world, will use the GENESIS Version 2.0 Global Climate Model, interactivity coupled to a predictive vegetation model (IBIS) and asynchronously coupled to a new high resolution dynamical ice sheet model specifically designed for GCM investigations of ice-sheet initiation and development. A systematic series of sensitivity tests will assess the role of atmospheric CO2, orbital parameter, atmosphere-vegetation feedbacks, paleogeography, and ocean heat transport in the initiation and growth of glacial ice on Antarctica.