Summary of the Article:

**Methane Model in the Community Land Model (CLM)**

The article discusses the representation of methane (CH4) biogeochemical processes in the CLM (Community Land Model). The methane model, referred to as CLM4Me, is based on several previously published models.

**Key Aspects of the Methane Model:**

1. **Model Structure and Flow**: The article first outlines the overall structure and flow of information in the methane model.

2. **Methane Mass Balance**: The model represents the complex and interacting processes involved in net surface CH4 emissions, including CH4 production, ebullition, aerenchyma transport, and CH4 oxidation.

3. **Methane Production**: The model incorporates methods to represent CH4 production processes.

4. **Ebullition and Aerenchyma Transport**: The model includes representations of CH4 release through ebullition and aerenchyma transport.

5. **Methane Oxidation**: The model accounts for CH4 oxidation processes.

6. **Reactive Transport Solution**: The model uses a reactive transport solution approach, considering boundary conditions, numerical solutions, and the interface with the water table.

7. **Seasonal Inundation Effects**: The model captures the impact of seasonal inundation on CH4 production and other related processes.

The article highlights that the CLM4Me model, while building on previous models, has incorporated several new process representations and parameterizations to improve the mechanistic modeling of net surface CH4 emissions.