The CWRF, the Climate extension of the WRF, has been developed with a comprehensive Conjunctive Surface-Subsurface Process (CSSP) component to predict mesoscale terrestrial hydrology variations and land-atmosphere interactions. Standalone simulations as driven by observational data reveal clear advantage of CSSP over some other existing land surface models (LSMs) in consistently representing surface fluxes, runoff, and soil moisture. This study investigates the climate-hydrology interactions at intraseasonal-interannual scales using the CWRF coupled with the CSSP versus other LSMs. CWRF retrospective integrations during 1979-2010 are compared against observations to depict the relative abilities of the CSSP and other LSMs in predicting the U.S. terrestrial hydrology cycle (precipitation, runoff, soil moisture) and the consequences on regional climate characteristics, including extreme events. Diagnostic analyses are conducted to understand the physical processes and underlying mechanisms that may cause such result contrast. These include differences in coupling between surface, PBL, cumulus, and radiation processes, as well as teleconnection between distinct feedback regions.

For presentation at the 92nd Annual Meeting: the 26th Conference on Hydrology, 22–26 January 2012, New Orleans, Louisiana.