pyrcel.activation.arg2000¶
-
pyrcel.activation.
arg2000
(V, T, P, aerosols=[], accom=1.0, mus=[], sigmas=[], Ns=[], kappas=[], min_smax=False)¶ Computes droplet activation using a psuedo-analytical scheme.
This method implements the psuedo-analytical scheme of [ARG2000] to calculate droplet activation an an adiabatically ascending parcel. It includes the extension to multiple lognormal modes, and the correction for non-unity condensation coefficient [GHAN2011].
To deal with multiple aerosol modes, the scheme includes an expression trained on the mode std deviations, \(\sigma_i\)
\[S_\text{max} = 1 \bigg/ \sqrt{\sum \frac{1}{S^2_ ext{mi}}\left[H(f_i, g_i)\]ight]}
This effectively combines the supersaturation maximum for each mode into a single value representing competition between modes. An alternative approach, which assumes the mode which produces the smallest predict Smax sets a first-order control on the activation, is also availableParameters: - V, T, P : floats
Updraft speed (m/s), parcel temperature (K) and pressure (Pa)
- aerosols : list of
AerosolSpecies
List of the aerosol population in the parcel; can be omitted if
mus
,sigmas
,Ns
, andkappas
are present. If both supplied, will useaerosols
.- accom : float, optional (default=:const:constants.ac)
Condensation/uptake accomodation coefficient
- mus, sigmas, Ns, kappas : lists of floats
Lists of aerosol population parameters; must be present if
aerosols
is not passed, butaerosols
overrides if both are present.- min_smax : boolean, optional
If True, will use alternative formulation for parameterizing competition described above.
- aerosols : list of
Returns: - smax, N_acts, act_fracs : lists of floats
Maximum parcel supersaturation and the number concentration/activated fractions for each mode
[ARG2000] Abdul-Razzak, H., and S. J. Ghan (2000), A parameterization of aerosol activation: 2. Multiple aerosol types, J. Geophys. Res., 105(D5), 6837-6844, doi:10.1029/1999JD901161.
[GHAN2011] Ghan, S. J. et al (2011) Droplet Nucleation: Physically-based Parameterization and Comparative Evaluation, J. Adv. Model. Earth Syst., 3, doi:10.1029/2011MS000074