org.geotools.nature

Class SeaWater

Object

SeaWater

public final class SeaWater
extends Object

Sea water properties as a function of salinity, temperature and pressure. Density is computed using the 1980 definition of Equation of State (EOS80). Units are:

• Salinity: Pratical Salinity Scale 1978 (PSS-78).
• Temperature: Celsius degrees according International Temperature Scale 1968 (ITS-68).
• Pressure: decibars (1 dbar = 10 kPa).

Since:

2.1

Author:

Bernard Pelchat, Martin Desruisseaux (PMO, IRD)

Field Summary

Fields

Modifier and Type	Field and Description
static double	STANDARD_CONDUCTIVITY Conductivity (in mS/cm) of a standard sea water sample.

Method Summary

Modifier and Type	Method and Description
static double	adiabeticTemperatureGradient(double S, double T, double P) Computes adiabetic temperature gradient as a function of salinity, temperature and pressure.
static double	conductivity(double S, double T, double P) Computes conductivity as a function of salinity, temperature and pressure.
static double	density(double S, double T, double P) Computes density as a function of salinity, temperature and pressure.
static double	densitySigmaT(double S, double T, double P) Computes density sigma-T as a function of salinity, temperature and pressure.
static double	depth(double P, double lat) Computes depth as a function of pressure and latitude.
static double	fusionTemperature(double S, double P) Computes fusion temperature (melting point) as a function of salinity and pressure.
static double	salinity(double C, double T, double P) Computes salinity as a function of conductivity, temperature and pressure.
static double	saturationO2(double S, double T) Computes saturation in disolved oxygen as a function of salinity and temperature.
static double	soundVelocity(double S, double T, double P) Computes sound velocity as a function of salinity, temperature and pressure.
static double	specificHeat(double S, double T, double P) Computes specific heat as a function of salinity, temperature and pressure.
static double	volume(double S, double T, double P) Computes volume as a function of salinity, temperature and pressure.
static double	volumeAnomaly(double S, double T, double P) Computes volumic anomaly as a function of salinity, temperature and pressure.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

STANDARD_CONDUCTIVITY

public static final double STANDARD_CONDUCTIVITY

Conductivity (in mS/cm) of a standard sea water sample. S is for Siemens (or Mho, its the same...).

See Also:

Constant Field Values

Method Detail

density

public static double density(double S,
                             double T,
                             double P)

Computes density as a function of salinity, temperature and pressure.

Parameters:

S - Salinity PSS-78 (0 to 42)

T - Temperature ITS-68 (-2 to 40°C)

P - Pressure in decibars (0 to 10⁵ dbar), not including atmospheric pressure.

Returns:

Density (kg/m³).

densitySigmaT

public static double densitySigmaT(double S,
                                   double T,
                                   double P)

Computes density sigma-T as a function of salinity, temperature and pressure. Density Sigma-T is equivalent to the true density minus 1000 kg/m³, and has typical values around 35. This computation avoid some rouding errors occuring in the true density computation.

Parameters:

S - Salinity PSS-78 (0 to 42)

T - Temperature ITS-68 (-2 to 40°C)

P - Pressure in decibars (0 to 10⁵ dbar), not including atmospheric pressure.

Returns:

Density Sigma-T (kg/m³).

volume

public static double volume(double S,
                            double T,
                            double P)

Computes volume as a function of salinity, temperature and pressure. This quantity if the inverse of density. This method is equivalent to 1/density(S,T,P).

Parameters:

S - Salinity PSS-78 (0 to 42)

T - Temperature ITS-68 (-2 to 40°C)

P - Pressure in decibars (0 to 10⁵ dbar), not including atmospheric pressure.

Returns:

Volume (m³/kg).

volumeAnomaly

public static double volumeAnomaly(double S,
                                   double T,
                                   double P)

Computes volumic anomaly as a function of salinity, temperature and pressure. Volumic anomaly is defined as the sea water sample's volume minus a standard sample's volume, where the standard sample is a sample of salinity 35, temperature 0°C and the same pressure. In pseudo-code, volumeAnomaly is equivalent to volume(S,T,P)-volume(35,0,P).

Parameters:

S - Salinity PSS-78 (0 to 42)

T - Temperature ITS-68 (-2 to 40°C)

P - Pressure in decibars (0 to 10⁵ dbar), not including atmospheric pressure.

Returns:

Volumic anomaly (m³/kg).

salinity

public static double salinity(double C,
                              double T,
                              double P)

Computes salinity as a function of conductivity, temperature and pressure.

Parameters:

C - Conductivity in mS/cm (millisiemens by centimeters). Multiply par STANDARD_CONDUCTIVITY if C is not a real conductivity, but instead the ratio between the sample's conductivity and the standard sample's conductivity.

T - Temperature ITS-68 (-2 to 40°C)

P - Pressure in decibars (0 to 10⁵ dbar), not including atmospheric pressure.

Returns:

Salinity PSS-78.

conductivity

public static double conductivity(double S,
                                  double T,
                                  double P)

Computes conductivity as a function of salinity, temperature and pressure.

Parameters:

S - Salinity PSS-78 (0 to 42)

T - Temperature ITS-68 (-2 to 40°C)

P - Pressure (0 to 10⁵ dbar), not including atmospheric pressure.

Returns:

Conductivity in mS/cm.

specificHeat

public static double specificHeat(double S,
                                  double T,
                                  double P)

Computes specific heat as a function of salinity, temperature and pressure.

Parameters:

S - Salinity PSS-78.

T - Temperature (°C).

P - Pressure (dbar), not including atmospheric pressure.

Returns:

Specific heat (J/(kg×°C)).

fusionTemperature

public static double fusionTemperature(double S,
                                       double P)

Computes fusion temperature (melting point) as a function of salinity and pressure.

Parameters:

S - Salinity PSS-78.

P - Pressure (dbar), not including atmospheric pressure.

Returns:

Melting point (°C).

adiabeticTemperatureGradient

public static double adiabeticTemperatureGradient(double S,
                                                  double T,
                                                  double P)

Computes adiabetic temperature gradient as a function of salinity, temperature and pressure.

Parameters:

S - Salinity PSS-78.

T - Temperature (°C).

P - Pressure (dbar), not including atmospheric pressure.

Returns:

Adiabetic temperature gradient (°C/dbar).

depth

public static double depth(double P,
                           double lat)

Computes depth as a function of pressure and latitude.

Parameters:

P - Pressure (dbar), not including atmospheric pressure.

lat - Latitude in degrees (-90 to 90°)

Returns:

Depth (m).

soundVelocity

public static double soundVelocity(double S,
                                   double T,
                                   double P)

Computes sound velocity as a function of salinity, temperature and pressure.

Parameters:

S - Salinity PSS-78.

T - Temperature (°C).

P - Pressure (dbar), not including atmospheric pressure.

Returns:

Sound velocity (m/s).

saturationO2

public static double saturationO2(double S,
                                  double T)

Computes saturation in disolved oxygen as a function of salinity and temperature.

Parameters:

S - Salinity PSS-78.

T - Temperature (°C).

Returns:

Saturation in disolved oxygen (µmol/kg).