Conserving quantities related to potential vorticity in numerical models.

在理想状态下，流体动力学方程保留了流体质点上的机械能和位涡量。在地球大气和海洋的计算机模型中，已知势熵守恒（平均势涡的平方）可以防止向模型中最小空间尺度的虚假能量转移。由于加入了亚网格尺度的黏度，不能保存势熵的数值模型具有不切实际的大能量耗散。尽管如此，目前用于计算大气和海洋大尺度流动的几乎所有模型都不能在无粘极限下保存潜在熵。在这项研究中，斯克里普斯海洋学研究所的一名科学家将设计大气和海洋的数值模型，以保存能量、势熵和其他与势涡相关的量。预计这些模型将比目前使用的这一代数值模型更稳定，耗散更少。一名博士生将参与其中。因此，该项目将对模型开发的未来产生广泛的影响。

In the ideal, invscid limit, the equations of fluid dynamics conserve mechanical energy and the potential vorticity on fluid particles. In computer models of the Earth's atmosphere and ocean, the conservation of potential enstrophy (the average, squared potential vorticity) is known to prevent a spurious transfer of energy to the smallest spatial scales of the model. Numerical models that fail to conserve potential enstrophy have an unrealistically large dissipation of energy due to the sub-grid-scale viscosity that is added. Despite this, virtually all of the models which are currently used to compute large-scale flow in the atmosphere and the ocean do not conserve potential enstrophy in the inviscid limit. In this study, a scientist at Scripps Institution of Oceanography will design numerical models for the atmosphere and ocean that conserve energy, potential enstrophy and other quantities related to potential vorticity. These models are expected to be more stable and less dissipative than the current generation of numerical models in use. A PhD student will be involved. The project therefore will have a broad impact on the future of model development.