[Chemistry]
¶
This header describes the chemical composition of the
atmosphere. The type of model used is defined by the
chemistry_type
variable.
- The available
chemistry_type
are: ace
ACE equlibrium chemistry
Class:
ACEChemistry
taurex
Free chemistry
Class:
TaurexChemistry
custom
User-type chemistry. See Custom Types
ACE Equlibrium Chemistry¶
Warning
Since version 3.1 this has been removed from the base TauREx package. You can restore this chemical scheme by writing:
pip install taurex_ace
chemistry_type = ace
chemistry_type = equilibrium
Equilibrium chemistry using the ACE FORTRAN program. Fortran compiler required
Keywords¶
Variable |
Type |
Description |
Default Value |
|
|
Stellar metallicity in solar units |
1.0 |
|
|
C/O ratio |
0.54951 |
Fitting Parameters¶
Parameter |
Type |
Description |
|
|
Stellar metallicity in solar units |
|
|
C/O ratio |
Taurex Chemistry¶
chemistry_type = taurex
chemistry_type = free
This chemistry type allows you to define individual abundance profiles for each molecule. Molecules are either active or inactive depending on whats available. If no cross-sections are available then the moelcule is not actively absorbing.
Keywords¶
Variable |
Type |
Description |
Default |
|
|
Gas or gases to fill the atmosphere with |
H2,He, |
|
|
Ratio between first fill gas and every other fill gas |
0.749 |
Fitting Parameters¶
On its own, this chemistry model provides fitting parameters relating to the fill gases used.
These are only created when more than one fill gas is defined.
Here, we use [Gas-0]
to designate the first gas defined in the fill gas list and
[Gas-(number)]
to designate the nth gas after the main gas. If we have a
gas list like:
fill_gases = H2,He,CO2,
then [Gas-1]_[Gas-0] == He_H2
and [Gas-2]_[Gas-0] == CO2_H2
:
Parameter |
Type |
Description |
|
|
Ratio of nth fill gas vs first fill gas |
However molecules are defined as subheaders with the subheader being the name of the molecule.
Each molecule can be assigned an abundance profile through the gas_type
variable.
For example, to describe a chemical profile with water in constant abundance in the atmosphere
is simply done like so:
[Chemistry]
chemistry_type = taurex
fill_gases = H2,He,
ratio = 0.1524
[[H2O]]
gas_type = constant
mix_ratio = 1e-4
- For each molecule, the available
gas_type
are: constant
Constant abundance profile
Class:
ConstantGas
twopoint
Two Point abundance profile
Class:
TwoPointGas
twolayer
Two layer abundance profile
Class:
TwoLayerGas
Gas Profiles¶
For these profiles, the fitting parameters generated have
the name associated with the name of the molecule. For example:
H2O_P
, CH4_S
etc. Because of this, we will use the moniker:
[Mol]
. Replacing this with the appropriate molecule will give you
the correct fitting parameter name.
e.g. [Mol]_surface
should be H2O_surface
for water etc.
Constant Profile¶
gas_type = constant
An abundance profile that is constant with height of the atmosphere
Keywords¶
Variable |
Type |
Description |
Default |
|
|
Mixing ratio of molecule |
1e-4 |
Fitting Parameters¶
Parameter |
Type |
Description |
|
|
Mixing ratio of molecule |
Two Layer Profile¶
gas_type = twolayer
An abundance profile where abundance is defined on the planet surface and top of the atmosphere with a pressure point determining the boundary between the layers. Smoothing is applied.
Keywords¶
Variable |
Type |
Description |
Default |
|
|
Mixing ratio at BOA |
1e-4 |
|
|
Mixing ratio at TOA |
1e-8 |
|
|
Pressure boundary (Pa) |
1e3 |
|
|
Smoothing window |
10 |
Fitting Parameters¶
Parameter |
Type |
Description |
|
|
Mixing ratio at BOA |
|
|
Mixing ratio at TOA |
|
|
Pressure boundary (Pa) |