Hydrostatic Pressure:

p = gz

z = depth

g = grav. Acc.

= density of seawater

PGF per Unit Mass:

1/ x dp/dx = g x tan()

The potential temperature of a parcel of fluid at pressure P is the temperature that the parcel would acquire if adiabatically brought to a standard reference pressure P0, usually 1000 millibars. Image is potential temperature at 5m depth (7/1/04)

The stream function can be used to plot streamlines, which represent the trajectories of particles in a steady flow. Streamlines are perpendicular to equipotential lines. Considering the particular case of fluid dynamics, the difference between the stream function values at any two points gives the volumetric flow rate (or volumetric flux) through a line connecting the two points.

Hysteresis:The dependence of the state of a system on the history of its state. Physics the lag in a variable property of a system with respect to the effect producing it as this effect varies

In oceanography, dynamic topography refers to the topography of the sea surface related to the dynamics of its own flow. In hydrostatic equilibrium, the surface of the ocean would have no topography, but due the ocean currents, its maximum dynamic topography is on the order of two meters

Dynamics: The forces and motions that characterize a system

Entrainment is the movement of one fluid by another

Diapycnal: definition.In the ocean, density always increases with increasing depth. However, surfaces of constant density (called "isopycnals") are not always level. Wind, the rotation of the Earth, and other processes cause density surface to slope. For example, a wind blowing along the coast can cause cold water which is usually deep to rise up to the surface, leading to water that is too cold to swim in, even in summer. The direction at right angles to the local isopycnal surface is called the “diapycnal” (i.e., across-isopycnal) direction. The angle between the diapycnal direction and vertical (i.e., directly out from the Earth) is always very small, a fraction of a degree at most. However, the difference between the two coordinates is very important to oceanographers, because the slope of isopycnals tells us a great deal about how the ocean is moving, and how it can interact with the coast and the atmosphere.

Stochastic resonance is observed when noise added to a system changes the system's behavior in some fashion. More technically, SR occurs if the signal-to-noise ratio of a nonlinear system or device increases for moderate values of noise intensity. It often occurs in bistable . Strictly speaking, stochastic resonance occurs in bistable systems, when a small periodic (sinusoidal) force is applied together with a large wide band stochastic force (noise). The system response is driven by the combination of the two forces that compete/cooperate to make the system switch between the two stable states.