Sensitivity of the Community Land Model (CLM4.0) to key modeling parameters and modeling of key physical processes with focus on the arctic environment.

The purpose of this study was to identify major parameters and physical processes that have greatest impacts on the near surface energy balance in the Arctic environment. The historical data set for the period of 1948 to 2004 from National Center for Atmospheric Research (NCAR) was used to generate atmospheric forcing data for this analysis. The CLM 4.0 (Community Land Model) was used for land simulations of the point grid cell located near Fairbanks, Alaska. A range of hydrogeologic and thermal soil properties and vegetation characteristics were defined for the vegetation and soil data. The current approach used in CLM was modified to simulate soil moisture to allow for more realistic water table representation. Multiple CLM sensitivity runs were analyzed with regard to their effects on the feedbacks to the atmospheric model. This analysis allowed for identifying major parameters and important physical processes with the potential to impact the climate either in the short or long term. . Sensitivity of the Community Land Model (CLM4.0) to Key Modeling Parameters and Modeling of Key Physical Processes with Focus on the Arctic Environment