Geophysical fluid dynamics

Remarkably, this works well even for a highly compressible fluid like air as long as sound and shock waves can be ignored.

[2]: 2–3  Under these assumptions the Navier-Stokes equations are The left hand side represents the acceleration that a small parcel of fluid would experience in a reference frame that moved with the parcel (a Lagrangian frame of reference).

[3]: Chapter 8  In the ocean, convection can be thermal (driven by heat), haline (where the buoyancy is due to differences in salinity), or thermohaline, a combination of the two.

Where stratification occurs, there may be thin layers in which temperature or some other property changes more rapidly with height or depth than the surrounding fluid.

Depending on the main sources of buoyancy, this layer may be called a pycnocline (density), thermocline (temperature), halocline (salinity), or chemocline (chemistry, including oxygenation).

[2]: 208–214 In modeling buoyancy-driven flows, the Navier-Stokes equations are modified using the Boussinesq approximation.

Model forecast of Hurricane Mitch created by the Geophysical Fluid Dynamics Laboratory . The arrows are wind vectors and the grey shading indicates an equivalent potential temperature surface that highlights the surface inflow layer and eyewall region.
Internal waves in the Strait of Messina (photographed by ASTER ).