potential density

If potential density surfaces are used, the difference can be hundreds of meters, a far larger error.

Potential density adjusts for the effect of compression in two ways:

An isopycnal is a surface of constant potential density of water.

The enstrophy can be interpreted as another type of potential density (ie.

The potential density would then be calculated as:

The atmosphere and ocean are continuously stratified: potential density generally increases steadily downward.

The corresponding potential density anomaly is denoted by kg/m.

In oceanography, the symbol is used to denote potential density, with the reference pressure taken to be the pressure at the ocean surface.

Using these reference pressures can be defined the potential density surfaces, used in the analyses of ocean data and to construct models of the ocean current.

Potential density is a dynamically important property: for static stability potential density must decrease upward.

Neutral density surfaces, defined using another variable called neutral density ( ), can be considered the continuous analog of these potential density surfaces.

Because the compressibility of seawater varies with salinity and temperature, the reference pressure must chosen to be near the actual pressure to keep the definition of potential density dynamically meaningful.

The potential density of a fluid parcel at pressure is the density that the parcel would acquire if adiabatically brought to a reference pressure , often 1 bar (100 kPa).

It has a potential density of 27.76-27.78 mg/cm relatively to the surface layers, meaning it is denser, and thus sinks under the surface and remains homogeneous and unaffected by the surface fluctuations.

Whereas density changes with changing pressure, potential density of a fluid parcel is conserved as the pressure experienced by the parcel changes (provided no mixing with other parcels or net heat flux occurs).

There were subsurface maxima in the middle and low latitude regions, which is indicative of lateral mixing (advection) and diffusion processes along lines of constant potential density (isopycnals) in the upper ocean.

For how has been defined, neutral density surfaces can be considered the continuous analog of the commonly used potential density surfaces, which are defined over various discrete values of pressures (see for example and ).

Additionally, because mixing in the ocean interior is largely along lines of constant potential density rather than along lines of constant depth, mixing must be rotated relative to the coordinate grid- a process that can be computationally expensive.

Another distinguishing feature of LSW is its weak vertical density gradient, and during CONVEX-91 this was found between depths of 500 and 2,000m within the density range of (where is potential density referenced to a depth of 1,500db).