WATER_density_rho(): water density according to a temperature a salinity

About:

Calculate the density of water.

\begin{equation} \rho = 1000 \times \left(1 - \frac{T+288.9414}{508929.2\times \left(T+68.12963 \right)}\times \left(T-3.9863 \right)^2\right) \end{equation}

$a_1 = 0.824493$

$a_2 = 0.0040899$

$a_3 = 0.000076438$

$a_4 = 0.00000082467$

$a_5 = 0.0000000053675$

\begin{equation} A = a_1 - a_2\times T + a_3\times T^2 -a_4 \times T^3 + a_5\times T^4 \end{equation}

$b_1 = 0.005724$

$b_2 = 0.00010227$

$b_3 = 0.0000016546$

\begin{equation} B = -b_1 + b_2 \times T - b_3\times T^2 \end{equation} \begin{equation} C = 0.00048314 \end{equation} \begin{equation} \rho_{salinity} = \rho + A\times s + B\times s^{3/2} + C\times s^2 \end{equation} 

 Where,

• $T$, temperature - $^oC$;
• $\rho$, density of pure water - $\frac{kg}{m^3}$;
• $s$, water salinity - $\frac{g}{kg}$;
• $\rho_{salinity}$, density of water - $\frac{kg}{m^3}$

more information about water density please see Wikipedia.

Module: WaterProperties

Function: WATER_density_rho(t,s)

Definition of variables:

• t, temperature - ºC;
• s, salinity - g/kg

Sample code:

from WaterProperties import *

t = 25 #oC
s = 2.5 #g/kg
rho = WATER_density_rho(t,s)

print("rho:",rho,"kg/m3")

Result:

rho: 998.959606051 kg/m3