Modeling the Effects of an Ice Sheet on the Climate of a Supercontinent

冈瓦纳冰原和更新世冰原差不多大，但有一个重要的区别，那就是它们位于一个超大陆上。先前超大陆构造的能量平衡模式实验模拟的冰盖与大季节循环的相互作用表明，这是一种重要的气候响应。冰覆盖的冈瓦纳超大陆的极冷温度与温暖的热带纬度相结合，应该导致极端的斜压性，并表明明显的融化。该奖项将重点研究冈瓦纳冰期最大时期的气候系统响应，采用一般环流模式和五种不同的冰川覆盖范围和米兰科维奇轨道配置情景。米兰科维奇轨道变化的影响将在使用当前倾斜对称轨道、南半球凉爽的夏季-温暖的冬季轨道和南半球炎热的夏季-寒冷的冬季轨道的模拟矩阵中进行探索。对全球环流、温度和水文循环模式的分析将为了解冰川期的全球气候提供数据。对模拟的区域冰盖方面的关注（例如，地表热收支、水文循环）将澄清关于超大陆上冰川冰盖与大陆地块的大季节温度范围的兼容性的争论。结果将根据现有的地质数据进行验证。

The Gondwanan ice sheets were approximately as large as those in the Pleistocene, but differed in one important respect, they were located on a supercontinent. The interaction of the ice sheet with the large seasonal cycle simulated in previous energy balance model experiments for a supercontinent configuration suggests a response of significant climatic interest. Extremely cold temperatures over the ice-covered supercontinent of Gondwanan coupled to warm tropical latitudes should result in extreme baroclinicity and suggest significant melting. This award will focus research on the climate system response during the time period of maximum Gondwanan glaciation, with a general circulation model and five different scenarios of glacial ice extent and Milankovitch orbital configurations. The influence of Milankovitch orbital variations will be explored in a matrix of simulations using a present tilt-symmetric orbit, a cool summer-warm winter orbit for the Southern Hemisphere, and a hot summer-cold winter orbit for the Southern Hemisphere. Analysis of global patterns of circulation, temperature, and the hydrologic cycle will provide data to understand the global climate during glacial periods. Attention to the regional ice-sheet aspects of the simulations (e.g. surface heat budget, hydrologic cycle) will clarify the debate on the compatibility of a glacial ice sheet on a supercontinent with the large seasonal temperature ranges suggested for large land masses. Results will be validated against available geologic data.