Atmospheric and geophysical fluid dynamics

这项建议寻求继续支持的研究一方面涉及数学地球物理方面的问题，另一方面涉及大气、海洋和固体地球过程的流体力学方面的问题，这两个领域在气候动力学和气候系统历史方面的工作相互交叉。这种交叉的一个例子体现在我开发的独特理论中，该理论描述了第四纪晚期冰旋回造成的行星形状的变形和伴随的海平面变化。保留在太空中的GRACE卫星提供的随时间变化的重力场观测极大地证实了该模型的预测。正在为古气候模拟对比项目(PMIP3)制作该模型的进一步改进版本，以便编写下一份气专委报告。这将包括对地幔粘度深度依赖性的改进表示，以及对欧亚冰川消融的更好的约束模型。产生的数据集将被我自己的团队和国际上用于从末次冰盛期到全新世的气候变化的新的耦合模拟中。制作工作还开始应用现已完成的关于地球地幔一般环流和气体巨行星大气层气象层的新的三维球面数值模式，前者旨在增进我们对压力引起的相变对径向混合长度的影响的理解，后者则旨在提供对纬向喷流的起源和稳定性的理解，这些纬向喷流主导着观测到的用以表征这些天体的平均流速的极到极变化。这项关于气体巨型纬向流的工作正在导致一种新的非流体静力干燥动力核心的发展，这种核心可以替代在更传统的大气GCM中使用的那些。在更小的空间尺度上，在纯流体力学领域，我已经开始了一个新的项目，关于完全三维湍流在混合平均密度层结时可能以非扩散方式起作用的效率，这项工作说明了这种湍流过程在大尺度模式中应该被“参数化”的方式。

The research for which this proposal seeks continuing support addresses issues in mathematical geophysics on the one hand and in the fluid mechanics of atmospheric, oceanic and solid Earth processes on the other, areas that intersect in work on climate dynamics and climate system history. An example of such intersection is embodied in the unique theory I have developed to describe the deformations of planetary shape and accompanying variations in sea level caused by the Late Quaternary glacial cycle. The predictions of this model have been dramatically confirmed by the time-dependent gravity field observations provided by the GRACE satellites that remain in space. A further refined version of the model is being produced for the Paleoclimate Modelling Intercomparison Project (PMIP3) in work leading to the next IPCC report. This will include an improved representation of the depth dependence of mantle viscosity and a better constrained model of Eurasian deglaciation. The data sets produced will be employed by my own group and internationally in new coupled simulations of climate variability from Last Glacial Maximum to Holocene. Production work is also beginning on application of the now complete new three dimensional spherical numerical models of the general circulation of the mantle of the Earth and the atmospheric weather layers of the Gas Giant planets, the former directed towards improving our understanding of the impact of pressure induced phase transitions on the radial mixing length, and the latter towards providing an understanding of the origin and stability of the zonal jets that dominate the pole-to-pole variations of mean-flow velocity observed to characterize these objects. This work on Gas Giant zonal flows is leading towards the development of a new non-hydrostatic dry dynamical core that may be substituted for those used in more conventional atmospheric GCM's. On smaller spatial scales and in the area of pure fluid mechanics, I have begun a new project on the efficiency with which fully three-dimensional turbulence may act non-diffusively in mixing a mean density stratification, work that speaks to the way in which such turbulent processes should be "parameterized" in large-scale models.