Open AccessA catchment‐based approach to modeling land surface processes in a general circulation model: 2. Parameter estimation and model demonstration
Author(s) -
Ducharne Agnès,
Koster Randal D.,
Suarez Max J.,
Stieglitz Marc,
Kumar Praveen
Publication year - 2000
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2000jd900328
Subject(s) - surface runoff , forcing (mathematics) , environmental science , drainage basin , range (aeronautics) , hydrology (agriculture) , general circulation model , circulation (fluid dynamics) , evaporation , climatology , meteorology , geology , climate change , geography , ecology , oceanography , materials science , cartography , geotechnical engineering , composite material , biology , physics , thermodynamics
The viability of a new catchment‐based land surface model (LSM) developed for use with general circulation models is demonstrated. First, simple empirical functions, tractable enough for operational use in the LSM, are established that faithfully capture the control of topography on the subgrid variability of soil moisture and the surface water budget, as predicted by theory. Next, the full LSM is evaluated off‐line. Using forcing and validation data sets developed for the Project for Intercomparison of Land‐Surface Parameterization Schemes Phase 2c, the minimally calibrated model is shown to reproduce observed evaporation and runoff fluxes successfully in the Red‐Arkansas River Basin. A complementary idealized study that employs the range of topographic variability seen over North America demonstrates that the simulated surface water budget does vary strongly with topography, which can, by itself, induce variations in annual runoff as high as 20%.