[Model]

This header defines the type of forward model (FM) that will be computed by TauREx3. There are only four distinct forward model_type:

• transmission

  • Transmission forward model

• emission

  • Emission forward model

• directimage

  • Direct-image forward model

• custom

  • User-type forward model, See Custom Types

Both emission and direct image also include an optional keyword ngauss which dictates the number of Gaussian quadrate points used in the integration. By default this is set to ngauss=4.

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Contributions

Contributions define what processes in the atmosphere contribute to the optical depth. These contributions are defined as subheaders with the name of the header being the contribution to add into the forward model.Any forward model type can be augmented with these contributions.

Examples

Transmission spectrum with molecular absorption and CIA from H2-He and H2-H2:

[Model]
model_type = transmission
    [[Absorption]]

    [[CIA]]
    cia_pairs = H2-He,He-He

Emission spectrum with molecular absorption, CIA and Rayleigh scattering:

[Model]
model_type = emission
ngauss = 4
    [[Absorption]]

    [[CIA]]
    cia_pairs = H2-He,He-He

    [[Rayleigh]]

The following sections give a list of available contributions

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Molecular Absorption

[[Absorption]]

Adds molecular absorption to the forward model. Here the active molecules contribute to absorption. No other keywords are needed. No fitting parameters.

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Collisionally Induced Absorption

[[CIA]]

Adds collisionally induced absorption to the forward model. Requires cia_path to be set. Both active and inactive molecules can contribute. No fitting parameters

Keywords

Variable	Type	Description
cia_pairs	list	List of molecular pairs. e.g. H2-He, H2-H2

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Rayleigh Scattering

[[Rayleigh]]

Adds Rayleigh scattering to the forward model. Both active and inactive molecules can contribute. No keywords or fitting parameters.

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Optically thick clouds

[[SimpleClouds]] or [[ThickClouds]]

A simple cloud model that puts a infinitely absorping cloud deck in the atmosphere.

Keywords

Variable	Type	Description
clouds_pressure	float	Pressure of top of cloud-deck in Pa

Fitting Parameters

Variable	Type	Description
clouds_pressure	float	Pressure of top of cloud-deck in Pa

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Mie scattering (Lee)

[[LeeMie]]

Computes Mie scattering contribution to optical depth Formalism taken from: Lee et al. 2013, ApJ, 778, 97

Keywords

Variable	Type	Description
lee_mie_radius	float	Particle radius in um
lee_mie_q	float	Extinction coefficient
lee_mie_mix_ratio	float	Mixing ratio in atmosphere
lee_mie_bottomP	float	Bottom of cloud deck in Pa
lee_mie_topP	float	Top of cloud deck in Pa

Fitting Parameters

Parameter	Type	Description
lee_mie_radius	float	Particle radius in um
lee_mie_q	float	Extinction coefficient
lee_mie_mix_ratio	float	Mixing ratio in atmosphere
lee_mie_bottomP	float	Bottom of cloud deck in Pa
lee_mie_topP	float	Top of cloud deck in Pa

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Mie scattering (BH)

[[BHMie]]

Computes a Mie scattering contribution using method given by Bohren & Huffman 2007

Keywords

Variable	Type	Description
bh_particle_radius	float	Particle radius in um
bh_cloud_mix	float	Mixing ratio in atmosphere
bh_clouds_bottomP	float	Bottom of cloud deck in Pa
bh_clouds_topP	float	Top of cloud deck in Pa
mie_path	str	Path to molecule scattering parameters
mie_type	cloud or haze	Type of mie cloud

Fitting Parameters

Parameter	Type	Description
bh_particle_radius	float	Particle radius in um
bh_cloud_mix	float	Mixing ratio in atmosphere
bh_clouds_bottomP	float	Bottom of cloud deck in Pa
bh_clouds_topP	float	Top of cloud deck in Pa

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Mie scattering (Flat)

[[FlatMie]]

Computes a flat absorbing region of the atmosphere across all wavelengths

Keywords

Variable	Type	Description
flat_mix_ratio	float	Opacity value
flat_bottomP	float	Bottom of absorbing region in Pa
flat_topP	float	Top of absorbing region in Pa

Fitting Parameters

Parameter	Type	Description
flat_mix_ratio	float	Opacity value
flat_bottomP	float	Bottom of absorbing region in Pa
flat_topP	float	Top of absorbing region in Pa