< p >我认为不同作者可能想要区分深对流混合雾沫从纯粹的扩散或重力wave-driven混合。深层搅拌主要发生在一定区域(南极洲附近,在拉布拉多海),因为它需要一个非常强大的冷却表面触发对流。扩散或重力破浪混合可以发生在任何地方。扩散可能包括直接过程(如双扩散或“盐指法”)或间接cabbeling或thermobaricity等过程。如果他们的预算是基于模型,这些类的过程很可能分别输出,所以这是一个很简单的部门。< / p >I would break it down as follows, with an eye toward model output:
- Vertical advection comes from the advection by resolved or implied vertical velocity. This would include Ekman pumping and any other vertical velocity you might get from an omega-equation.
- Entrainment-detrainment comes from convective processes. These require special handling, since many ocean models until recently would not resolve these processes. (They might occur in areas that are only a few kilometers in width, far below the lateral resolution.) These processes can mix together entire parts of the water column at once and often do not care about vertical gradients; they are "non-local".
- Diffusive processes are very local/small-scale and depend on vertical gradients of heat and salt. Cabbeling, thermobaricity, and double diffusion are some examples. I include gravity wave-driven mixing here because although the gravity wave generation process is non-local, when they break they can only mix locally within the water column.
This kind of breakdown makes sense for a global ocean model, where these three things are handled by three separate modules. For super-hi-res regional models and non-hydrostatic models, advection and convection start to merge together, and if the model is truly eddy-resolving, entrainment becomes a mix of advection followed by diffusion. How you budget these processes depends on the spatial and temporal scales of the model.