## 2.25.6. CH4 Oxidation[¶](#ch4-oxidation "Permalink to this headline")
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CLM represents CH4 oxidation with double Michaelis-Menten kinetics ([Arah and Stephen 1998](https://escomp.github.io/ctsm-docs/versions/master/html/tech_note/References/CLM50_Tech_Note_References.html#arahstephen1998); [Segers 1998](https://escomp.github.io/ctsm-docs/versions/master/html/tech_note/References/CLM50_Tech_Note_References.html#segers1998)), dependent on both the gaseous CH4 and O2 concentrations:

(2.25.11)[¶](#equation-24-11 "Permalink to this equation")\\\[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)](https://escomp.github.io/ctsm-docs/versions/master/html/tech_note/References/CLM50_Tech_Note_References.html#schnellking1996), we take \\(F\_{\\theta } = {e}^{-P/{P}\_{c}}\\), where _P_ is the soil moisture potential and \\({P}\_{c} = -2.4 \\times {10}^{5}\\) mm.

