The development of a dynamic root distribution for the community land model with carbon-nitrogen interactions

Land surface models have employed a variety of fine root distributions, but it is unclear which is the most accurate. To test if the choice of root distribution mattered, a sensitivity test was conducted on the Community Land Model with Carbon-Nitrogen Interactions (CLM-CN) for three different root distributions. The sensitivity test showed that the CLM-CN was sensitive to root distribution, and thus the choice of root distribution did matter. An existing dynamic root distribution was adapted to use observed soil nutrient profiles instead of the original prescribed nutrient profiles and was run in the CLM-CN. The new dynamic root distribution was evaluated against existing root distributions and was shown to have: (1) vegetation with reduced water stress and (2) modeled fine root carbon profiles which most closely matched the observed soil organic carbon profiles. The new dynamic root distribution appears to be an improvement over existing root distributions.;Keywords: root distributions, land surface models, global soil grids...