rothc_py.constants

Decomposition rate constant for Microbial Biomass (yr⁻¹).

Scaling factor in the clay-dependent CO2/(BIO+HUM) partitioning equation.

Coefficient in the clay-dependent CO2/(BIO+HUM) partitioning equation.

Coefficient in the clay-dependent CO2/(BIO+HUM) partitioning equation.

Exponential decay coefficient in the clay-dependent partitioning equation.

Decomposition rate constant for Decomposable Plant Material (yr⁻¹).

Threshold for spin-up convergence: maximum annual TOC change (t C/ha).

Factor to convert open-pan evaporation to evapotranspiration.

Fraction of (BIO+HUM) that becomes Microbial Biomass.

Fraction of (BIO+HUM) that becomes Humified Organic Matter.

Fraction of farmyard manure carbon that enters DPM pool.

Fraction of farmyard manure carbon that enters HUM pool.

Fraction of farmyard manure carbon that enters RPM pool.

Decomposition rate constant for Humified Organic Matter (yr⁻¹).

Default initial age of inert organic matter, implying negligible 14C (years).

Coefficient A in the Jenkinson temperature rate modifier equation.

Coefficient B in the Jenkinson temperature rate modifier equation.

Coefficient C in the Jenkinson temperature rate modifier equation.

Empirical timescale for the removal of atmospheric ¹⁴C in months^-1.

This is based on fitting an single exponential decary,

$ x(t) = x(0) e^{-\lambda t} $

to two (time, excess modern C) points: (1964, 96%) and (2007, 6.8%), which yields λ = 0.616 years^-1 or λ = 0.00513 months^-1.

Number of months per year.

Conventional half-life of radiocarbon-14 (years).

Mean lifetime of radiocarbon-14, used in δ14C calculations (years).

Maximum rate modifying factor for moisture (no water stress).

Minimum rate modifying factor for moisture (maximum water stress).

Rate modifying factor for bare soil (no plant cover).

Rate modifying factor for covered soil (with plant cover).

Decomposition rate constant for Resistant Plant Material (yr⁻¹).

Fraction of maximum TSMD at which rate modifier equals 1.0.

Inverse of bare soil divisor (1/1.8) for reduced evaporation from bare soil.

Coefficient A in the maximum soil moisture deficit equation.

Coefficient B in the maximum soil moisture deficit equation.

Coefficient C in the maximum soil moisture deficit equation.

Reference soil depth for scaling maximum soil moisture deficit (cm).

Minimum temperature (°C) below which decomposition rate is zero.

Minimum value threshold for numerical stability in radiocarbon age calculations.