pyrcel.thermo.kohler_crit¶
- pyrcel.thermo.kohler_crit(T, r_dry, kappa, approx=False)¶
Critical radius and supersaturation of an aerosol particle.
The critical size of an aerosol particle corresponds to the maximum equilibrium supersaturation achieved on its Kohler curve. If a particle grows beyond this size, then it is said to “activate”, and will continue to freely grow even if the environmental supersaturation decreases.
This function computes the critical size and and corresponding supersaturation for a given aerosol particle. Typically, it will analyze
Seq()
for the given particle and numerically compute its inflection point. However, if theapprox
flag is passed, then it will compute the analytical critical point for the approximated kappa-Kohler equation.- Parameters:
- Tfloat
ambient air temperature, K
- r_dryfloat
dry particle radius, m
- kappafloat
particle hygroscopicity parameter
- approxboolean, optional (default=False)
use the approximate kappa-kohler equation
- Returns:
- (r_crit, s_crit)tuple of floats
Tuple of \((r_\text{crit},\, S_\text{crit})\), the critical radius (m) and supersaturation of the aerosol droplet.
See also
Seq
equilibrium supersaturation calculation