Absorption cross section

Absorption cross section data sets provide the monochromatic absorption cross section spectrum of a given absorbing species at specific pressure and temperature conditions.

Data access

Important

Most absorption cross section data used internally by the Eradiate team cannot be distributed easily due to their large size (around 1TB). This, in particular, means that the support for monochromatic simulation is currently limited to selected atmospheric profiles. We plan to improve the delivery of those spectra in the future.

Distributed data sets are managed the data store (see Introduction for details).

Identifier format

Identifiers for absorption cross section data sets are constructed based on the format {absorber}-{engine}-{wmin}_{wmax} where:

• absorber is the name of the absorber (e.g. CH4),

• engine indicates the absorption cross section engine used (e.g. spectra),

• wmin is the minimum wavenumber value in cm^-1,

• wmax is the maximum wavenumber value in cm^-1.

Structure

Absorption cross section data sets include one data variable:

• monochromatic absorption cross section (xs)

one optional data variable:

• mixing ratios (mr),

three dimension coordinates:

• wavenumber (w),

• pressure (p),

• temperature (t),

(temperature may be a non-dimension coordinate) and one optional dimension coordinate:

• molecules (m).

Data variable xs is tabulated with respect to w, p and t (optional).

Data variable mr, when present, is tabulated with respect to m. Data variable mr should be included in data sets where the absorber is a mixture of different absorbing molecules.