Improved cross‐scale snow cover simulations by developing a scale‐aware ground snow cover fraction parameterization in the Noah‐MP land surface model

However, SCF is a large source of uncertainty, partially because of the scale‐dependent nature of snow depletion curves that is not parameterized by LSMs. Using the spatially and temporally complete observationally‐informed STC‐MODSCAG and Snow Data Assimilation System data sets, we develop a new scale‐aware ground SCF parameterization and implement it into the Noah‐MP LSM.

The new scale‐aware parameterization significantly reduces ground SCF errors and the scale‐dependence of errors in the western U.S (WUS) compared with the baseline ground SCF formulation. Specifically, the baseline formulation overestimates ground SCF by 4%, 6%, 9%, and 12% at 1‐km, 3‐km, 13‐km, and 25‐km resolutions in the WUS, respectively, whereas biases from the enhanced scale‐aware scheme are reduced to 0%–2% in box model simulations and do not exhibit a relationship with spatial scales.