Late-Pliocene Ice-Age Initiation

关键古气候的周期或准周期变化 指标（底栖有孔虫.18O和.13C，%CaCO3， 浮游有孔虫种群）大约发生在 3和2.47百万年。 利用数据分析和敏感性 与大气环流模式的实验，该项目将 探索这些振荡是否是由 相对较小的北方冰盖， 将冰山崩解到开阔的大西洋， 北极海冰界限的变化。 在许多可能的原因中 北方半球冰河时期的最后一个世纪， 东南亚大规模构造隆升的影响 （西藏、喜马拉雅山）和美国西南部（科罗拉多 高原，落基山脉）对北方半球行星波 (and（地球表面的气候）。 新的分析 将扩展高分辨率同位素时间序列， 使用包括交互式混合层的模型进行实验 海洋将更准确地定义气候的全部影响， 晚新生代构造隆升。 %%% 该项目将研究气候波动之前， "更新世"冰期的开始和 冰河时代本身（实际上开始于320万年前， 大约在更新世开始前100万年）。 该项目将利用气候的计算机模型 互动，以检查反馈机制， 气候和海洋环境， 主要的高海拔陆地 这将是第一 试图模拟这么多的变量， 气候变化导致了冰川的形成 年龄

Periodic or quasi-periodic variations in key paleoclimatic indicators (benthic foraminiferal .18O and .13C, %CaCO3, and planktonic foraminiferal populations) occurred between roughly 3 and 2.47 Myr. Using data analyses and sensitivity experiments with General Circulation Models, this project will explore whether these oscillations were driven by variations in relatively small Northern Hemisphere ice sheets that did not calve icebergs to the open Atlantic ocean or by large-scale changes in Arctic sea-ice limits. Among many possible causes of the Northern Hemisphere ice age, the project will explore the effect of large-scale tectonic uplift in Southeast Asia (Tibet, Himalayas) and the American southwest (Colorado Plateau, Rockies) on the Northern Hemisphere planetary waves (and thus on climate at the earth's surface). New analyses will extend the high-resolution isotopic time series, and experiments with a model including an interactive mixed-layer ocean will define more accurately the full climatic effects of Late-Cenozoic tectonic uplift. %%% This project will examine climatic fluctuations preceding the initiation of the "Pleistocene" ice ages and the initiation of the ice age itself (which actually began 3.2 million years ago; approximately 1.0 million years before the Pleistocene began). The project will utilize computer models of climate interactions in order to examine the feed-back mechanisms of climate and ocean environments with the tectonic uplifts of major high-altitude land masses. This will be the first attempt to model so many of the variables the cause of respond to climate changes that resulted in the initiation of the ice ages.