Physical Relations Governing the Response of the Global Sea Ice Cover to Climate Change

施耐德1107795加州理工学院的PI将使用系统的方法来阐明控制海冰厚度和面积范围的季节性和较长的时间尺度的过程。首先，他们将确定当前综合全球气候模型（GCM）中的可靠响应。接下来，他们将开发基本理论来解释这些反应，从考虑物理第一原理开始，继续通过模拟具有越来越高的复杂性的模型层次，并最终通过卫星观测来测试理论。一个主要的工具将是一个理想化的气氛？海冰GCM，它有助于弥合理解基本过程和综合GCM模拟之间的差距。使用这个模型和其他模型，他们将在海冰变化的更广泛背景下测试为北极海冰退缩而开发的理论，这些海冰变化涵盖了从完全被冰覆盖到完全无冰的星球的整个气候范围。这些理论将被用来解释观测到的海冰变化，并评估目前GCM预测中不同模型的方面，例如21世纪北极海冰退缩的速度。具体问题包括：海冰和气候系统其他组成部分之间的相互作用如何决定半球海冰覆盖的季节性循环？海冰对气候变化的敏感性受哪些物理原理支配？这项研究将阐明有关海冰和气候动态的一些最基本的问题。它将弥合最先进的GCM模拟和基本物理理解之间的差距，从而为模型评估提供指标，为模型改进提出建议，并减少未来海冰退缩预测的不确定性。通过探索海冰在各种气候条件下的退缩，它将把过去和未来可能的北极海冰变化放在更广泛的背景下。

Schneider 1107795California Institute of TechnologyThe PIs will use a systematic approach to elucidate the processes that control sea ice thickness and areal extent on seasonal and longer timescales. First, they will identify responses that are robust among current comprehensive global climate models (GCMs). Next, they will develop fundamental theories to explain these responses, beginning with the consideration of physical first principles, continuing through simulations with a hierarchy of models with increasing levels of complexity, and culminating in tests of the theories with satellite-derived observations. A principal tool will be an idealized atmosphere?sea ice GCM, which helps bridge the gap between understanding of fundamental processes and simulations with comprehensive GCMs. Using this and other models, they will test the theories developed for Arctic sea ice retreat in the broader context of sea ice changes in a continuum of climates spanning the full range from a completely ice-covered to a completely ice-free planet. These theories will be used to interpret observed sea ice changes and to evaluate the aspects of current GCM projections that differ among the models, such as the rate of 21st-century Arctic sea ice retreat. Specific questions to be addressed include:? How do interactions between sea ice and other components of the climate system determine the seasonal cycle of hemispheric sea ice cover?? What physical principles govern the sensitivity of sea ice to climate changes?The proposed research will elucidate some of the most fundamental questions about the dynamics of sea ice and climate. It will bridge the gap between state-of-the-art GCM simulations and fundamental physical understanding, thereby providing metrics for model assessment, suggesting ways for model improvement, and reducing the uncertainty in the prediction of future sea ice retreat. By exploring sea ice retreat in a wide range of climates, it will place past and possible future Arctic sea ice changes in a broader context.