PartMC  2.6.1
Input File Format: Aerosol Distribution Profile

Read an array of aero_dists with associated times and rates from the given file.

[in,out]fileSpec file to read data from.
[in,out]aero_dataAero data.
timesTimes (s).
ratesRates (s^{-1}).
aero_distsAero dists.

An aerosol distribution profile input file must consist of three lines:

  • the first line must begin with time and should be followed by $N$ space-separated real scalars, giving the times (in s after the start of the simulation) of the aerosol distrbution set points — the times must be in increasing order
  • the second line must begin with rate and should be followed by $N$ space-separated real scalars, giving the values at the corresponding times
  • the third line must begin with dist and should be followed by $N$ space-separated filenames, each specifying an aerosol distribution in the format Input File Format: Aerosol Distribution at the corresponding time

The units of the rate line depend on the type of aerosol distribution profile:

  • Emissions aerosol profiles have rates with units m/s — the aerosol distribution number concentrations are multiplied by the rate to give an emission rate with unit #/(m^2 s) which is then divided by the current mixing layer height to give a per-volume emission rate.
  • Background aerosol profiles have rates with units $\rm s^{-1}$, which is the dilution rate between the background and the simulated air parcel. That is, if the simulated number concentration is $N$ and the background number concentration is $N_{\rm back}$, then dilution is modeled as $\dot{N} = r N_{\rm back} - r N$, where $r$ is the rate.

Between the specified times the aerosol profile is interpolated step-wise and kept constant at its last value. That is, if the times are $t_i$, the rates are $r_i$, and the aerosol distributions are $a_i$ (all with $i = 1,\ldots,n$), then between times $t_i$ and $t_{i+1}$ the aerosol state is constant at $r_i a_i$. Before time $t_1$ the aerosol state is $r_1 a_1$, while after time $t_n$ it is $r_n a_n$.

Example: an emissions aerosol profile could be:

 time  0          600        1800       # time (in s) after sim start
 rate  1          0.5        1          # scaling factor in m/s
 dist  dist1.dat  dist2.dat  dist3.dat  # aerosol distribution files

Here the emissions between 0 min and 10 min are given by dist1.dat (with the number concentration interpreted as having units 1/(m^2 s)), the emissions between 10 min and 30 min are given by dist2.dat (scaled by 0.5), while the emissions after 30 min are given by dist3.dat.

See also: