pyrtlib.utils.kgkg_to_kgm3#
- pyrtlib.utils.kgkg_to_kgm3(q: ndarray, p: ndarray, t: ndarray) ndarray#
Utils function to convert from \(kg/kg\) to \(kg/m^3\). [Jacobson]
NWP models provide cloud liquid and ice water content in units \(kg/kg\). To convert to \(g/m^3\) multiply the result of this function to the value in \(kg/kg\).
\[LWC = q_{liq} \frac{10^2 P}{R_{moist} T}\]\[R_{moist} = R_{dry} (1 + \frac{1 - \epsilon}{\epsilon} q_{h2o})\]\[\epsilon = \frac{M_{h2o}}{M_{dry}}\]\[R_{dry} = \frac{R}{M_{dry}}\]where: \(q_{liq}\) is the mass mixing ratio for liquid cloud, \(P\) is the atmospheric pressure in hPa, \(T\) is the atmospheric temperature in K, \(R_{moist}\) is the moist air gas constant (in J kg-1 K-1), \(R_{dry}\) is the gas constant for dry air and \(q_{h2o}\) is the specific humidity (given as the ratio between the mass of water vapor and the mass of moist air)
The same equations are used for ice clouds, by replacing LWC by IWC and \(q_{liq}\) by \(q_{ice}\)
- Parameters:
q (numpy.ndarray) – specific humidity (\(kg/kg\))
p (numpy.ndarray) – pressure (hPa)
t (numpy.ndarray) – temperature (K)
- Returns:
[description]
- Return type:
References
Examples using pyrtlib.utils.kgkg_to_kgm3#
