Land Surface Heterogeneity in the Cooperative Atmosphere Surface Exchange Study (CASES-97). Part II: Analysis of Spatial Heterogeneity and Its Scaling

Abstract

Abstract Multiscale atmospheric forcing data at 1-, 5-, and 10-km scales from the 1997 Cooperative Atmosphere Surface Exchange Study (CASES-97) were used to drive three uncoupled land surface models: the National Center for Atmospheric Research Land Surface Model version 1 (NCAR LSM), the Oregon State University Land Surface Model (OSU LSM), and the Japan Atomic Energy Research Institute's Atmosphere–Soil–Vegetation Model (SOLVEG). The data included high-resolution, gauge-corrected precipitation estimates from dual-polarization radar, with the experimental period covering the spring green-up process. The effects of increasing scale on modeled estimates of the domain mean flux were more pronounced when there was greater heterogeneity of the land surface in terms of the surface vegetation, although this result was model dependent. All models made use of prescribed parameters based on dominant land cover at the different scales, not effective parameters, leading to situations where the coarser-scale flux res...