What is tform?¶

tform is a physics-based Mars climate simulation framework for studying how the Martian atmosphere, temperature, and cryosphere evolve over time — and how targeted engineering interventions can drive the planet toward habitability.

It is built for researchers and engineers who want to run rigorous, reproducible simulations of planetary-scale terraforming scenarios, from a single Martian day to centuries of greenhouse gas injection.

What it simulates¶

At its core, tform integrates a coupled system of ordinary differential equations (ODEs) describing:

State variable	Symbol	Unit
Surface temperature	\(T\)	K
Atmospheric pressure	\(P\)	Pa
Polar CO₂ ice mass	\(M_\text{ice}\)	kg

These evolve under solar forcing, atmospheric radiative transfer, orbital mechanics, and optional greenhouse gas injections.

Supported experiment types¶

`sol` — Single Martian day¶

Simulates one full diurnal cycle (~24.6 hours) at a given latitude and longitude. Tracks the temperature response as the sun rises, peaks, and sets. Useful for understanding local climate conditions at a specific site.

`year` — One Martian year¶

Runs a full Martian year (~687 Earth days) with realistic seasonal cycles driven by orbital eccentricity (\(e = 0.0934\)) and axial tilt (\(25.19°\)). Captures CO₂ cap sublimation/deposition and pressure seasonality.

`multi` — Multi-latitude sweep¶

Runs three canonical latitudes simultaneously: 45°N, equator (0°), and 40°S — all at 137°E longitude. Shows the latitudinal temperature and pressure gradient across a Martian year.

`spots` — Landmark sites¶

Runs four geographically important Martian sites in a single call, with elevation-corrected initial conditions:

Site	Latitude	Elevation
Olympus Mons	18.65°N	+21 km
Elysium Mons	25.02°N	+14 km
Hellas Basin	42.4°S	−7 km
South Polar Cap	90°S	+2 km

`intervention` — GHG injection campaign¶

Multi-year simulation of super-greenhouse gas injection (SF6, CF4, C2F6, and others). Tracks the radiative forcing accumulation, greenhouse factor evolution, and resulting temperature and pressure trajectory over decades to centuries.

Supported forcings and controls¶

External forcings passed to the physics engine¶

Forcing key	Description
`solar_radiation`	Zenith angle, transmittance, TOA override, surface energy
`solar_wind`	Electron density, magnetic field, wind speed, proton density
`cosmic_radiation`	GCR flux, SEP flux, TOA dose rate, atmospheric shielding
`giant_planets_gravity`	Jupiter and Saturn effective gravitational accelerations
`mars_moons_gravity`	Phobos and Deimos direct and tidal accelerations

Atmosphere composition controls¶

Species column tendencies (\(\text{kg m}^{-2}\,\text{s}^{-1}\)) can be applied to any atmospheric species:

O2, N2, H2, H, CO2, CO, O3, Ar, He, super_ghg, Ne, Kr, Xe

Water and cryosphere controls¶

Control	Description
`water_ice_tendency_kg_m2_s`	Add/remove bulk solid water
`water_liquid_tendency_kg_m2_s`	Add/remove liquid water
`water_phase_change_tendency_kg_m2_s`	Transfer between ice and liquid
`polar_ice_h2o_tendency_kg_m2_s`	Polar H₂O cap tendency
`polar_ice_co2_tendency_kg_m2_s`	Polar CO₂ cap tendency

Soil controls¶

soil_compound_tendency_mass_fraction_per_s — gradual regolith chemistry change
soil_compound_delta_mass_fraction — direct per-step override

GHG interventions¶

Compound	Atmospheric lifetime
CF₄	>50,000 yr
SF₆	3,200 yr
C₂F₆	10,000 yr
NF₃	500 yr
CHF₃, CH₂F₂, CH₃F, C₃F₈	varies
CH₄	12 yr
N₂O	114 yr

Integration modes¶

Mode	Method	When to use
`accurate`	4th-order Runge-Kutta	Science runs, publications
`fast`	Reduced-order analytic updates	Parameter sweeps, interactive exploration

Built-in presets¶

11 ready-to-run configurations: current-mars, gale-crater, early-mars, terraforming-phase1, equatorial, polar, olympus-mons, elysium-mons, hellas-basin, south-polar-cap, landmark-spots.

See CLI Presets for full details.