Modeling the Glacial Evolution on 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纬高纬度地区向寒冷条件的转变代表了新生代全球气候-海洋系统最根本的重组。确定南极冰盖形成、发展和周期性波动的机制对我们了解全球气候系统和未来气候变化非常重要。从始新世早期温暖的“温室”气候模式到今天的“冰屋”世界，新生代的降温趋势早已在古生物学、同位素学和沉积学证据中得到认可。该奖项旨在回答以下问题：1)在始新世中晚期，是什么长期的古环境变化导致了有限的南极冰的增长；2)在渐新世早期（-33.7 ma），是什么引发了南极东部冰盖的快速增长。对始新世晚期/渐新世早期气候响应的全面调查，将使用GENESIS 2.0版全球气候模式，旨在分离从“温室”到“冰窖”世界转变过程中可能的气候强迫机制和反馈的相对作用。交互耦合到预测植被模型（IBIS），并异步耦合到一个新的高分辨率动态冰盖模型，该模型专为冰盖的形成和发展的GCM调查而设计。一系列系统的敏感性试验将评估大气CO2、轨道参数、大气-植被反馈、古地理和海洋热输送在南极洲冰川形成和生长过程中的作用。

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.