Validation of the community land model and an improved soil parameterization scheme in typical wetland sites

Wetlands´ soil hydrology and temperature changes greatly affect methane emissions, and further affect climate. Wetland processes are not modeled well yet in the community land model (CLM) and further study is needed. Wetlands are represented as saturated organic soil, instead of being treated as water bodies only without soil and vegetation in CLM. Wetland soils are discretized to fibric, hemic, and sapric layers accounting for the typical variations in hydraulic characteristics of organic soils in the newly parameterized model. Spin-up is achieved by repeating the full range of available years 3 times (3 spin-up cycles). Daily model output is averaged to monthly output for analysis. The original model (CLM3_cntrl) and the modified wetland scheme model (CLM3_wet) are run independently. Sensible and latent heat fluxes and soil temperatures are validated. The results show that the state variables are improved through the wetland soils parameterization compared to the original CLM model.