Land surface parameterizations of GCMs and macroscale hydrological models

Climatic variation and the possibility of anthropogenically-caused climatic change have emphasized the need for global hydrological cycle models able to simulate the impacts of climate on the atmosphere, continents and oceans . To date, global atmospheric and oceanic models have been developed but, t o the best of the author's knowledge, there are no continental hydrological models. Instead, hydrological models continue to develop at the catchment scale and the land phase component of the global hydrologic cycle is modele d as parameterizations within atmospheric models. The author argues that th is is not the best solution; that the present land surface components of at mospheric models do not accurately model land phase hydrology and that, ins tead, atmospheric and oceanic models should be linked to continental-scale hydrological models to form a true model of the global hydrological cycle.