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

模拟南极洲的冰川演化和古近纪从“温室”世界到“冰室”世界的转变

• 批准号: 9905890
• 负责人: Robert DeConto
• 金额: $ 19.74万
• 依托单位: University of Massachusetts Amherst
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-06-01 至 2004-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9905890&HistoricalAwards=false
• 关键词: Modeling; Glacial; Evolution; Antarctica; Paleogene

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.

南极洲东部的冰川作用以及与此相关的南半球高纬度地区向寒冷状态的转变是新生代全球气候-海洋系统最根本的重组。 确定南极冰盖的成核、发展和周期性波动的机制对我们理解全球气候系统和未来气候变化至关重要。 从始新世早期温暖的“温室”气候模式到今天的“冰库”世界，新生代的冷却趋势早已在古生物学，同位素和沉积学证据中得到认可。 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有限的南极冰的增长，2）是什么引发了渐新世早期（-33.7 ma）东南极冰盖的快速增长。 对始新世晚期/渐新世早期气候呼应的全面调查，旨在分离可能的气候强迫机制和反馈在从“温室”到“冰库”世界的转变中的相对作用，将使用GENESIS 2.0版全球气候模型，与预测植被模型（IBIS）耦合的交互性异步耦合到一个新的高分辨率动态冰盖模式专门设计的GCM调查冰盖的启动和发展。 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、古地理和海洋热传输在南极洲冰川冰的形成和生长中的作用。