Methane Oxidation Filter in Thawing Permafrost

Permafrost carbon feedback modeling usually stops at "methane is produced and released," but a real soil column contains a biological filter in between. This simulation renders a 3D active-layer soil column split by an adjustable water table: below it, waterlogged anoxic soil produces methane at a temperature-dependent rate; above it, methanotrophic bacteria in the oxic, unsaturated soil consume methane via pseudo-first-order kinetics before it can escape. Individual CH₄ molecules are tracked as instanced particles performing a random walk (a physical stand-in for Fickian diffusion) up through the column, each one either oxidized in the filter zone or emitted to the atmosphere at the surface. Live readouts track the emission flux, the in-soil oxidation rate, and the overall oxidation efficiency — the fraction of produced methane the biofilter actually stops — which collapses as the water table rises toward the surface, illustrating why abrupt wetting during permafrost thaw can spike methane emissions even when production itself hasn't changed.