CrunchFlow

Knowledge graph centered on CrunchFlow with 32 nodes and 111 connections. Top connected: Relationships between CO2, thermodynamic limits on, carbon cycling, East River, soil respiration, weathering.

Method synopsis

Mathematical framework deriving power-law relationships between pCO2 and equilibrium solute concentrations based on reaction stoichiometry and equilibrium constants. Applied to assess silicate weathering feedback strength.

Synthesized from method descriptions across 1 paper using this protocol.

Procedure as described in the canonical source

Steps below were extracted from the paper that introduces this protocol — Relationships between CO2, thermodynamic limits on silicate weathering, and the strength of the silicate weathering feedback (2018), Earth and Planetary Science Letters. Implementations in other papers (listed below) may differ.

1. Set up CrunchFlow reactive transport model
   Initialize 1-D weathering profiles with mineral assemblage composition of 18.2% wt. each plagioclase feldspar (An20) and K-feldspar, 60.6% wt. quartz, and 3% wt. halloysite. Set initial porosity at 30% and halloysite as dominant secondary mineral based on comparison with simulated equilibrium concentrations.
   Quantities: 18.2% plagioclase, 18.2% K-feldspar, 60.6% quartz, 3% halloysite by weight; 30% porosityDuration: Simulations run over 100 year timescalesConditions: Temperature set at 15°C
   Equipment: CrunchFlow reactive transport model
2. Run weathering simulations
   Simulate weathering profiles across pCO2 values ranging from 10^2 to 10^6 ppm with infiltration fluxes of 0.5-10 m/yr. Run both open-system (constant pCO2 maintained) and closed-system (no gas flux) scenarios. Set domain length to 25 m to allow fluids to reach equilibrium with primary and secondary minerals.
   Quantities: pCO2 range: 10^2-10^6 ppm; infiltration fluxes: 0.5-10 m/yr; domain length: 25 mDuration: 100 year simulation timescalesConditions: 15°C temperature, saturated and unsaturated flow conditions
   Equipment: CrunchFlow model
3. Calculate equilibrium concentrations
   Extract final equilibrium concentrations from steady-state endpoints of CrunchFlow simulations. Plot [HCO3-]eq temporal evolution and compare with theoretical scaling relationships derived from equilibrium constants and reaction stoichiometry.

Typical Equipment

• Mathematical derivation

Output Measurements

• equilibrium bicarbonate concentrations
• weathering feedback strength

Papers Using This Protocol (2)

Species Studied With This Protocol

Places Where Used