AN APPROACH TO REMOTE-SENSING AND NUMERICAL MODELING OF OROGRAPHIC CLOUDS AND PRECIPITATION FOR CLIMATIC WATER-RESOURCES ASSESSMENT

State-of-the-art numerical models combined with new remote sensing tec hnologies offer powerful means for determining the water budgets of cl oud systems and addressing regional water resources issues. With speci fic examples from current technologies and a three-dimensional numeric al model, this paper discusses the potential for accurately measuring and modeling the formation and fallout of mountain precipitation, a cr itical factor in the global climate system because it affects water re sources. This paper describes application of the model and remote sens ors to meet the goals of programs such as the Global Energy and Water Cycle Experiment (GEWEX). To accurately predict precipitation, general circulation models that have 100-km grid spacing require parameteriza tion of the effects of subgrid-scale processes within cloud systems. T he contribution of scales of atmospheric motion 10-20 km in forming pr ecipitation and determining its distribution on mountain ranges is dem onstrated.