Numerical validation of the land surface process component of an LSP/R model

The University of Michigan’s land surface process/radiobrightness (LSP/R) model was developed as a step toward linking a traditional SVAT model to satellite microwave observations. The LSP model simulates land–air interactions and estimates surface fluxes, temperature and moisture profiles in soil and vegetation when forced with observed weather. These estimates are used by a microwave emission model, called the R model, that predicts terrain brightness temperatures. In this paper, we evaluate accuracy of the numerical methods used in the LSP model. Such rigorous tests were not conducted during the early development of the model. We describe three test-scenarios that included comparing the numerical solution with an analytic solution, evaluating coupled energy and moisture transport for a simple case, and calculating errors in energy and mass balance in the model for a realistic case using field observations. The original version of the model was modified to make it more applicable to the field conditions for the third test-case. Results from these tests demonstrate the physical self-consistency of the model and its successful implementation for the simple scenarios, and argue for its extendibility to more realistically complex cases.