Cenozoic Antarctic glaciation: An integrated atmosphere - Ocean - Ice Sheet Model Approach

在始新世-渐新世边界（约3500万年前），南极洲广泛的冰川作用和与之相关的向较冷温度的转变代表了地球历史上最基本的全球气候重组之一。与此同时，南大洋门户——德雷克海峡和塔斯曼海峡的打开，导致南极绕极流的形成，从而使南极大陆被孤立。除了海洋环境外，其他全球现象，如大气二氧化碳浓度下降和轨道结构，也促成了南极持续冰期的开始。通过这个项目，我们解决了这些过程对南极冰盖形成的影响。我们特别强调了海洋环流、潜热输送以及冰盖动力学的综合建模方法。将详细分析南极上空大气环流、温度变化和积雪的变化及其强迫因子。南极冰盖发育阈值的确定将为始新世-渐新世过渡时期的古气候记录提供新的视角。

The widespread glaciation of Antarctica and the associated shift towards colder temperatures at the Eocene-Oligocene boundary (about 35 million years ago) represents one of the most fundamental reorganisations of global climate in the earth s history. During the same time, the opening of the Southern Ocean gateways, the Drake Passage and the Tasman Gateway, led to the formation of the Antarctic Circumpolar Current and hence to the isolation of the Antarctic continent. Apart from the oceanic regime, other global phenomena such as the declining atmospheric carbon dioxide concentration and the orbital configuration, contributed to the onset of a persistent Antarctic glaciation. With this project we address the impact of each of these processes on the formation of the Antarctic Ice Sheet. We put special emphasis on the ocean circulation, latent heat transport as well as on ice sheet dynamics in an integrated modelling approach. Shifts in atmospheric circulation, temperature changes, and snow accumulation over Antarctica and their forcing factors will be analysed in detail. The identification of thresholds for the Antarctic ice sheet development will yield novel views for palaeoclimatic records at the Eocene-Oligocene transition.