1.6 KiB
2.25.6. CH4 Oxidation¶
CLM represents CH4 oxidation with double Michaelis-Menten kinetics (Arah and Stephen 1998; Segers 1998), dependent on both the gaseous CH4 and O2 concentrations:
(2.25.11)¶\[R_{oxic} =R_{o,\max } \left[\frac{C_{CH_{4} } }{K_{CH_{4} } +C_{CH_{4} } } \right]\left[\frac{C_{O_{2} } }{K_{O_{2} } +C_{O_{2} } } \right]Q_{10} F_{\vartheta }\]
where \(K_{CH_{4} }\) and \(K_{O_{2} }\) are the half saturation coefficients (mol m-3) with respect to CH4 and O2 concentrations, respectively; \(R_{o,\max }\) is the maximum oxidation rate (mol m-3 s-1); and \({Q}_{10}\) specifies the temperature dependence of the reaction with a base temperature set to 12 °C. The soil moisture limitation factor \(F_{\theta }\) is applied above the water table to represent water stress for methanotrophs. Based on the data in Schnell and King (1996), we take \(F_{\theta } = {e}^{-P/{P}_{c}}\), where P is the soil moisture potential and \({P}_{c} = -2.4 \times {10}^{5}\) mm.