parcel_model.activation.mbn2014

parcel_model.activation.mbn2014(V, T, P, aerosols=[], accom=1.0, mus=[], sigmas=[], Ns=[], kappas=[], xmin=1e-05, xmax=0.1, tol=1e-06, max_iters=100)

Computes droplet activation using an iterative scheme.

This method implements the iterative activation scheme under development by the Nenes’ group at Georgia Tech. It encompasses modifications made over a sequence of several papers in the literature, culminating in [MBN2014]. The implementation here overrides some of the default physical constants and thermodynamic calculations to ensure consistency with a reference implementation.

Parameters:

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, and kappas are present. If both supplied, will use aerosols.

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, but aerosols overrides if both are present

xmin, xmax : floats, opional

Minimum and maximum supersaturation for bisection

tol : float, optional

Convergence tolerance threshold for supersaturation, in decimal units

max_iters : int, optional

Maximum number of bisections before exiting convergence

Returns:

smax, N_acts, act_fracs : lists of floats

Maximum parcel supersaturation and the number concentration/activated fractions for each mode

[MBN2014]

Morales Betancourt, R. and Nenes, A.: Droplet activation parameterization: the population splitting concept revisited, Geosci. Model Dev. Discuss., 7, 2903-2932, doi:10.5194/gmdd-7-2903-2014, 2014.