Escape and outgassing
The [escape] section configures atmospheric escape (mass loss to space).
The [outgas] section configures volatile outgassing (partitioning between
interior and atmosphere).
Submodule documentation: ZEPHYRUS | CALLIOPE | atmodeller. See also Model description.
Atmospheric escape [escape]
| Parameter | Type | Default | Description |
|---|---|---|---|
module |
str or none | "zephyrus" |
Escape module: zephyrus (energy-limited), dummy (fixed rate), none (disabled) |
reservoir |
str | "outgas" |
Composition reservoir for escaping gas: outgas, bulk, pxuv |
ZEPHYRUS [escape.zephyrus]
Energy-limited escape: the mass loss rate scales with the XUV flux and escape efficiency.
| Parameter | Type | Default | Description |
|---|---|---|---|
Pxuv |
float | 5e-5 |
XUV opacity pressure level [bar] |
efficiency |
float | 0.1 |
Escape efficiency [0, 1] |
tidal |
bool | false |
Include tidal contribution to escape |
Dummy escape [escape.dummy]
A fixed bulk escape rate, useful for testing and parameter studies.
| Parameter | Type | Default | Description |
|---|---|---|---|
rate |
float | 0.0 |
Bulk escape rate [kg s\(^{-1}\)] |
Outgassing [outgas]
The outgassing module computes the thermodynamic equilibrium partitioning of volatiles between the atmosphere, silicate melt, and solid mantle at the planetary surface conditions.
| Parameter | Type | Default | Description |
|---|---|---|---|
module |
str | "calliope" |
Outgassing module: calliope (Gibbs minimisation), atmodeller (simplified), dummy (fixed) |
fO2_shift_IW |
float | 4.0 |
Redox state: fO\(_2\) offset from the iron-wustite buffer [log\(_{10}\) units] |
mass_thresh |
float | 1e16 |
Minimum volatile mass threshold [kg] |
h2_binodal |
bool | false |
Enable H\(_2\)-MgSiO\(_3\) miscibility gap model. true is rejected at config load: the parameterisation is not production ready |
T_floor |
float | 700.0 |
Clamp the outgassing temperature to this floor [K] before the chemistry solve |
solver_rtol |
float | 1e-4 |
Relative mass/equilibrium tolerance |
solver_atol |
float | 1e-6 |
Absolute mass/equilibrium tolerance |
CALLIOPE [outgas.calliope]
CALLIOPE uses Gibbs free energy minimisation to compute the gas-melt equilibrium at the planetary surface, handling C-H-N-O-S chemistry with fO\(_2\) buffering.
Species switches (set to false to exclude a species from the equilibrium)
| Parameter | Default | Species |
|---|---|---|
include_H2O |
true |
H\(_2\)O |
include_CO2 |
true |
CO\(_2\) |
include_N2 |
true |
N\(_2\) |
include_S2 |
true |
S\(_2\) |
include_SO2 |
true |
SO\(_2\) |
include_H2S |
true |
H\(_2\)S |
include_NH3 |
true |
NH\(_3\) |
include_H2 |
true |
H\(_2\) |
include_CH4 |
true |
CH\(_4\) |
include_CO |
true |
CO |
solubility |
true |
Enable melt-gas partitioning (false = all volatiles in atmosphere) |
Solver
| Parameter | Type | Default | Description |
|---|---|---|---|
nguess |
int | 1000 |
Maximum number of initial-guess samples for the equilibrium solver |
nsolve |
int | 3000 |
Maximum number of solver iterations per call |
p_guess_max |
float | 1e5 |
Upper bound [bar] of the cold-start surface-pressure draw, in (0, 1e7]; raise it to seed the solver higher for high-pressure (e.g. sub-Neptune) cases |
Atmodeller [outgas.atmodeller]
An alternative outgassing solver with configurable solubility laws and real-gas equations of state.
Note
atmodeller is an optional backend and is not installed with PROTEUS by
default; the standard outgassing module is calliope. Install it with
pip install "fwl-proteus[atmodeller]" before setting
outgas.module = "atmodeller". atmodeller is GPL-3.0 licensed; review
its terms before installing. See
Installation: optional modules.
| Parameter | Type | Default | Description |
|---|---|---|---|
solver_mode |
str | "robust" |
Root-finding mode: robust (better convergence) or basic (faster) |
solver_max_steps |
int | 256 |
Maximum solver iterations |
solver_multistart |
int | 10 |
Number of random restarts |
include_condensates |
bool | true |
Enable condensate formation (e.g. graphite) |
Solubility laws (set to "none" to disable dissolution for a species)
| Parameter | Default | Description |
|---|---|---|
solubility_H2O |
"H2O_peridotite_sossi23" |
Water solubility law |
solubility_CO2 |
"CO2_basalt_dixon95" |
CO\(_2\) solubility law |
solubility_H2 |
"H2_basalt_hirschmann12" |
H\(_2\) solubility law |
solubility_N2 |
"N2_basalt_dasgupta22" |
N\(_2\) solubility law |
solubility_S2 |
"S2_sulfide_basalt_boulliung23" |
S\(_2\) solubility law |
solubility_CO |
"CO_basalt_yoshioka19" |
CO solubility law |
solubility_CH4 |
"CH4_basalt_ardia13" |
CH\(_4\) solubility law |
Real gas EOS (set to "none" for ideal gas)
| Parameter | Default | Description |
|---|---|---|
eos_H2O |
"none" |
Water EOS |
eos_CO2 |
"none" |
CO\(_2\) EOS |
eos_H2 |
"none" |
H\(_2\) EOS |
eos_CH4 |
"none" |
CH\(_4\) EOS |
eos_CO |
"none" |
CO EOS |
See also: Escape modules | Outgassing modules