Read aero_data specification from a spec file.

Parameters

[in,out]	file	Spec file to read data from.
[in,out]	aero_data	Aero_data data.

A aerosol material data file must consist of one line per aerosol species, with each line having:

species name (string)
density (real, unit kg/m^3)
ions per fully dissociated molecule (integer) - used to compute kappa value if the corresponding kappa value is zero
molecular weight (real, unit kg/mol)
kappa hygroscopicity parameter (real, dimensionless) - if zero, then inferred from the ions value

This specifies both which species are to be recognized as aerosol consituents, as well as their physical properties. For example, an aerosol material data file could contain:

 # species  dens (kg/m^3)   ions (1)    molec wght (kg/mole)   kappa (1)
 SO4        1800            0           96e-3                  0.65
 NO3        1800            0           62e-3                  0.65
 Cl         2200            1           35.5e-3                0
 NH4        1800            0           18e-3                  0.65

Note that it is an error to specify a non-zero number of ions and a non-zero kappa value for a species. If both values are zero then that species has zero hygroscopicity parameter. If exactly one of kappa or ions is non-zero then the non-zero value is used and the zero value is ignored.