Summary:

## Vertical Discretization

The article discusses the vertical discretization of lakes in the CLM (Community Land Model) model. Key points:

1. Each grid cell currently contains one lake with prescribed or assumed depth, extinction coefficient, and fetch. This could be modified in future model versions.

2. The lake consists of:
   - 0-5 snow layers
   - 10 (global simulations) or 25 (site simulations) water and ice layers for the "lake body"
   - 10 "soil" layers
   - 5 bedrock layers

3. The water mass in each lake body layer is fixed, with the frozen mass-fraction as a state variable.

4. Resolved snow layers are present if the snow thickness meets a minimum threshold (4 cm by default).

5. The default layer thicknesses for global (50 m depth) and site simulations are provided.

6. For lakes with depths other than 50 m, the top layer is kept at 10 cm, and the other layers are adjusted to maintain fixed proportions. For lakes less than 1 m deep, all layers have equal thickness.

7. The snow, soil, and bedrock layer thicknesses follow the scheme used over non-vegetated surfaces, with modifications to the snow layer thickness rules.