Title: 2.25. Methane Model — ctsm CTSM master documentation

URL Source: https://escomp.github.io/ctsm-docs/versions/master/html/tech_note/Methane/CLM50_Tech_Note_Methane.html

Markdown Content:
The representation of processes in the methane biogeochemical model integrated in CLM \[CLM4Me; ([Riley et al. 2011a](https://escomp.github.io/ctsm-docs/versions/master/html/tech_note/References/CLM50_Tech_Note_References.html#rileyetal2011a))\] is based on several previously published models ([Cao et al. 1996](https://escomp.github.io/ctsm-docs/versions/master/html/tech_note/References/CLM50_Tech_Note_References.html#caoetal1996); [Petrescu et al. 2010](https://escomp.github.io/ctsm-docs/versions/master/html/tech_note/References/CLM50_Tech_Note_References.html#petrescuetal2010); [Tianet al. 2010](https://escomp.github.io/ctsm-docs/versions/master/html/tech_note/References/CLM50_Tech_Note_References.html#tianetal2010); [Walter et al. 2001](https://escomp.github.io/ctsm-docs/versions/master/html/tech_note/References/CLM50_Tech_Note_References.html#walteretal2001); [Wania et al. 2010](https://escomp.github.io/ctsm-docs/versions/master/html/tech_note/References/CLM50_Tech_Note_References.html#waniaetal2010); [Zhang et al. 2002](https://escomp.github.io/ctsm-docs/versions/master/html/tech_note/References/CLM50_Tech_Note_References.html#zhangetal2002); [Zhuang et al. 2004](https://escomp.github.io/ctsm-docs/versions/master/html/tech_note/References/CLM50_Tech_Note_References.html#zhuangetal2004)). Although the model has similarities with these precursor models, a number of new process representations and parameterization have been integrated into CLM.

Mechanistically modeling net surface CH4 emissions requires representing a complex and interacting series of processes. We first (section [2.25.1](#methane-model-structure-and-flow)) describe the overall model structure and flow of information in the CH4 model, then describe the methods used to represent: CH4 mass balance; CH4 production; ebullition; aerenchyma transport; CH4 oxidation; reactive transport solution, including boundary conditions, numerical solution, water table interface, etc.; seasonal inundation effects; and impact of seasonal inundation on CH4 production.

