Ocean Energetics, Tidal Conversion and Baroclinic Instability

该项目旨在了解海洋能量学、混合、斜压不稳定性、潮汐转换和温跃层的形成。该项目的第一部分是了解海洋能量学限制的分支和扩展。由于海洋中没有深层的浮力来源（除了小的地热加热），人们可以证明，在统计上稳定的状态下，每个深度的动能和势能储存库之间没有交换。动能的粘性耗散完全由潮汐力和风力平衡；在海洋中，势能基本上没有净转化为动能。将发展理论，以分析布辛内斯克能量学和海洋中可用和背景势能的平衡。第二个目标将是使用原始方程模拟和理论来检验斜压涡流在形成海洋温跃层中的作用。这将检验与内部重力波破裂相关的浮力通量被斜压涡流平衡的假设。准地转近似的扩展，其中背景分层是自一致地确定的，而不是简单地规定的，也将在数值上发展和实施。第三个目标将是在浮力频率变化很大的海洋中，通过实际的大地形来改进内部潮汐产生的计算。一种新的边界积分表示的解导致一个积分方程，使有效地计算由地形产生的内部重力波。这些目标涉及通过基于能量平衡的物理论证，确定海洋混合和湍流在决定地球气候长期变化方面的关键作用。

Ocean energetics, tidal conversion and baroclinic instabilityWilliam YoungScripps Institute of OceanographyThe project is directed at understanding ocean energetics, mixing, baroclinic instability, tidal conversion, and the formation of the thermocline. The first part of the project is understanding the ramifications and extensions of constraints on the ocean energetics. Because there are no deep sources of buoyancy in the ocean (apart from small geothermal heating), one can show that in a statistically steady state there is no exchange between the reservoirs of kinetic and potential energy at every depth. The viscous dissipation of kinetic energy is balanced totally by tidal and wind forcing; there is essentially no net transformation o f potential into kinetic energy in the ocean. Theory will be developed and directed at analyzing Boussinesq energetics and the balances of available and background potential energies in the ocean. A second goal will be use primitive equation simulations and theory to examine the role of baroclinic eddies in forming the ocean thermocline. This will test the hypothesis that buoyancy flux associated with breaking internal gravity waves is balanced by baroclinic eddies. An extension of the quasi-geostrophic approximation, in which the background stratification is self-consistently determined, rather than simply prescribed, will also be developed and implemented numerically. The third goal will be an improved calculation of the generation of the internal tide by realistically large topography in an ocean with strongly variable buoyancy frequency. A new boundary-integral representation of the solution leads to an integral equation that enables efficient calculation of the internal gravity waves generated by topography. These goals relate to establishing the critical role of ocean mixing and turbulence in determining long-term changes in the Earth's climate via physical arguments based on energy balances.