The approach begins with observations of relevant variables such as precipitation, soil moisture and vegetation. Sensors on board satellites and aircraft, surface radar, and networks of in situ instruments are used to collect data that are then converted into fields of useful variables by merging them with models.
Models impose important physical constraints on the estimates retrieval.
In other investigations simple-analytical and numerical models of physical processes are used to characterize coupled systems. The general premise is that coupled systems behave in ways that may not be evident when analyzing the individual components. I investigate the coupled behavior of surface and atmospheric boundary layer processes in order to characterize feedback mechanisms that affect weather predictability. The objectives are to map hydrologic response of the coupled system and to identify the influence of climatic and geologic controls on the spatial patterns of runoff, evaporation, surface soil moisture and groundwater. Since surface soil moisture is linked to other physical processes such as energy balance, information on its state are implicit in the conditions of the surface and near-surface atmosphere.