CCSM consists of five geophysical models: atmosphere (atm), sea-ice (ice), land (lnd), ocean (ocn), and land-ice (glc), plus a coupler (cpl) that coordinates the models and passes information between them. Each model may have "active," "data," "dead," or "stub" component version allowing for a variety of "plug and play" combinations.
The Community Land Model version 4.0 (CLM4.0) is the land model used in the CCSM4.0
Surface Datasets The PFT distribution is as in Lawrence and Chase (2007) except that a new cropping dataset is used (Ramankutty et al., 2008) and a grass PFT restriction has been put in place to reduce a high grass PFT bias in forested regions by replacing the herbaceous fraction with low trees rather than grass.
note on Lawrence and Chase reference above: the actual reference was not provided in the CLM documentation, but presumably the link I added is the correct paper.
The term "lake" is not found in the CLM documentation. The only mention of "lake" in the Lawrence and Chase reference is:
The CLM land surface model allows subgrid heterogeneity to be prescribed through fractional allocation of land cover to four or more Plant Functional Types (PFTs), and through prescribing the percentage of each grid cell occupied by ocean, lakes, wetlands, and glaciers.
CCSM4.0 Documentation does suggest ocean component may simulate freshwater:
OCN_COUPLING - Determine surface freshwater and heat forcing settings.
From:
Ke, Y & Leung, L & Huang, Maoyi & Coleman, Andre & Li, Hongyi & Wigmosta, Mark. (2012). Developing high resolution land surface parameters for Community Land Model. Geoscientific Model Development. 5. 1341-1362. 10.5194/gmd-5-1341-2012.
In the current version of CLM (CLM 4.0), the officially released land surface parameters are provided at 0.5◦ by 0.5◦ or coarser resolutions. For example, lake and wetland data were derived from Cogley’s (1991) 1◦ by 1◦ data for perennial freshwater lakes and swamps/marshes;
From:
Lawrence, D.M., K.W. Oleson, M.G. Flanner, C.G. Fletcher, P.J. Lawrence, S. Levis, S.C. Swenson, and G.B. Bonan, 2012: The CCSM4 Land Simulation, 1850–2005: Assessment of Surface Climate and New Capabilities. J. Climate, 25, 2240–2260, https://doi.org/10.1175/JCLI-D-11-00103.1
Efforts are also ongoing across the CLM development community to improve existing parameterizations, including projects on vegetation and soil carbon dynamics, nitrogen dynamics, lake-model thermodynamics (Subin et al. 2012)
Subin, Z. M., W. J. Riley, and D. Mironov, 2012: An improved lake model for climate simulations: Model structure, evaluation, and sensitivity analyses in, CESM1. J. Adv. Model. Earth Syst., in press
From paper:
The existing CLM4 lake model is identical to the version in CLM2 [
Bonan et al., 2002b; Zeng et al., 2002], is based on that of
Hostetler and Bartlein [1990], and incorporates code from LSM [Bonan, 1995] and CoLM [Dai et al., 2003], but it has not been compared to observations in its current form.
From Bonan et al (above):
Required surface input data for each grid cell include a biome type (which determines the patch fractions for each PFT), the fraction of the grid cell covered by lakes, the fraction covered by wetlands, soil texture (percent sand, silt, and clay), and soil color.
TABLE 1. Surface data required for LSM2 and CLM2, their base spatial resolution, and method of aggregation to the model’s grid.
Percent lake 1 degree source: LSM1