Influence of Grid Size and Terrain Resolution on Wind Field Predictions from an Operational Mesoscale Model

Abstract

Abstract One of the activities of the National Oceanic and Atmospheric Administration's Air Resources Laboratory is to predict the consequences of atmospheric releases of radioactivity and other potentially harmful materials. This paper describes the application of the Regional Atmospheric Modeling System (RAMS) to support air quality forecasting. The utility of using RAMS for real time prediction of local-scale flows and for detailed postevent analysis is examined for a Nuclear Regulatory Commission exercise at the Susquehanna nuclear power plant in Pennsylvania. During the exercise (10 December 1992) a strong East Coast low pressure system created complex interactions between the regional-scale and local topographical features of the Susquehanna River valley. Results from a series of sensitivity experiments indicated significant topographical forcing and vertical de-coupling although the synoptic forcing was quite strong in this relatively wide and shallow valley. The best agreement between the RAMS pre...