Atmosphere: Molecular absorption¶

Molecular absorption databases tabulate the volume absorption coefficient of a gas mixture against the spectral coordinates, the volume fraction of the mixture components, air pressure and air temperature. Eradiate’s built-in molecular absorption datasets are managed by the data store (see Data guide introduction for details).

Format (monochromatic)¶

Format xarray.Dataset (in-memory), NetCDF (storage)
Dimensions
- w: radiation wavelength
- p: air pressure
- t: air temperature
- x_M, where M is the molecule formula, e.g. x_H2O: gas mixture mole fractions
Coordinates (all dimension coordinates; when relevant, units are required and specified in the units metadata field)
- w float [length]
- p float [pressure]
- t float [temperature]
- x_M float [dimensionless]
Data variables (when relevant, units are required and specified in the units metadata field)
- sigma_a (w, p, t, x_M): volume absorption coefficient [length^-1]

Format (CKD)¶

Format xarray.Dataset (in-memory), NetCDF (storage)
Dimensions
- w: bin central wavelength
- wbv: bin bound (lower or upper)
- g: cumulative probability of the absorption coefficient distribution
- ng: number of quadrature points
- p: air pressure
- t: air temperature
- x_M, where M is the molecule formula, e.g. x_H2O: gas mixture mole fractions
Coordinates (all dimension coordinates; when relevant, units are required and specified in the units metadata field)
- w float [length]
- wbv str
- g float [dimensionless]
- ng int [dimensionless]
- p float [pressure]
- t float [temperature]
- x_M float [dimensionless]
Data variables (when relevant, units are required and specified in the units metadata field)
- sigma_a (w, p, t, x_M): volume absorption coefficient [length^-1]
- wbounds (w, wbv): bin bound values [length]
- error (w, ng): relative error on transmittance when using the quadrature, optional [dimensionless]