eradiate.thermoprops.util.compute_scaling_factors

eradiate.thermoprops.util.compute_scaling_factors(ds, concentration)

Compute the scaling factors to be applied to the mixing ratio values of each species in an atmosphere thermophysical properties data set, so that the integrated number/mass density and/or the number/mass density at the surface, match given values.

Parameters

• ds (Dataset) – Atmosphere thermophysical properties data set.

• concentration (dict) – Mapping of species (str) and target concentration (Quantity).

  If the target concentration has dimensions of inverse square length (\([L^{-2}]\)), the value is interpreted as a column number density for that given species and the scaling factor, \(f\), is obtained by dividing that column number density, \(N_{\mathrm{target}}\), by the initial column number density, \(N_{\mathrm{initial}}\):

  \[f = \frac{N_{\mathrm{target}}}{N_{\mathrm{initial}}}\]

  If the target concentration has dimensions of mass times inverse square length (\([ML^{-2}]\)), the value is interpreted as a column (mass) density for that species and the scaling factor is obtained by dividing that column mass density, \(\sigma_{\mathrm{target}}\), by the initial column mass density, \(\sigma_{\mathrm{initial}}\):

  \[f = \frac{\sigma_{\mathrm{target}}}{\sigma_{\mathrm{initial}}}\]

  If the target concentration has dimensions of inverse cubic length (\([L^{-3}]\)), the value is interpreted as a number density at the surface for that given species and the scaling factor is computed by dividing that number density at the surface, \(n_{\mathrm{surface, target}}\), by the initial number density at the surface, \(n_{\mathrm{surface, initial}}\):

  \[f = \frac{n_{\mathrm{surface, target}}}{n_{\mathrm{surface, initial}}}\]

  If the target concentration has dimensions of inverse cubic length (\([ML^{-3}]\)), the value is interpreted as a mass density at the surface for that given species and the scaling factor is computed by dividing that mass density at the surface, \(\sigma_{\mathrm{surface, target}}\), by the initial mass density at the surface, \(\sigma_{\mathrm{surface, initial}}\):

  \[f = \frac{\sigma_{\mathrm{surface, target}}}{\sigma_{\mathrm{surface, initial}}}\]

  If the target concentration is dimensionless, the value is interpreted as a mixing ratio at the surface for that given species and the scaling factor is computed by dividing that mixing ratio at the surface, \(x_{\mathrm{surface, target}}\), by the initial mixing ratio at the surface, \(x_{\mathrm{surface, initial}}\):

  \[f = \frac{x_{\mathrm{target}}}{x_{\mathrm{initial}}}\]

Returns

dict – Mapping of species (str) and scaling factors (float).