## 2.25.1. Methane Model Structure and Flow[¶](#methane-model-structure-and-flow "Permalink to this headline")
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The driver routine for the methane biogeochemistry calculations (ch4, in ch4Mod.F) controls the initialization of boundary conditions, inundation, and impact of redox conditions; calls to routines to calculate CH4 production, oxidation, transport through aerenchyma, ebullition, and the overall mass balance (for unsaturated and saturated soils and, if desired, lakes); resolves changes to CH4 calculations associated with a changing inundated fraction; performs a mass balance check; and calculates the average gridcell CH4 production, oxidation, and exchanges with the atmosphere.

