environmentaltools.processes.EOS_sea_water

environmentaltools.processes.EOS_sea_water(T, S)[source]

Compute density of seawater using equation of state (EOS).

Calculates seawater density as a function of temperature and salinity using the standard mean ocean water equation of state with pure water as reference. Includes pressure correction at 1 meter depth.

Parameters:

  • T (pd.DataFrame or np.ndarray) – Water temperature (°C)

  • S (pd.DataFrame or np.ndarray) – Salinity (psu - practical salinity units)

Returns:

Seawater density (kg/m³) at given temperature and salinity

Return type:

pd.DataFrame or np.ndarray

Notes

The calculation follows the standard seawater equation of state:

  1. Computes pure water density as function of temperature

  2. Adjusts for salinity effects

  3. Applies high pressure correction (p = 0.10073 bar at 1m depth)

The equation uses empirical polynomial coefficients derived from oceanographic measurements and is valid for typical ocean conditions.

Examples

>>> import pandas as pd
>>> T = pd.Series([15, 20, 25])  # Temperature in °C
>>> S = pd.Series([35, 35, 35])  # Salinity in psu
>>> rho = EOS_sea_water(T, S)
>>> print(rho)