DISCUSSIONS AND SUGGESTIONS ON USING DIFFERENT POINT-TO-POINT PROTOCOLS FOR TRANSPORT AND DISPERSION MODEL EVALUATIONS

Abstract: Historically, assessments of T&D models have involved comparisons to field trial data using quantities derived from observations – maximum concentrations, plume widths, or integrated concentrations over arcs at various downwind ranges. Recently several methodologies that compare observations and predictions paired in space and time have been developed. Two different protocols designed to deal with low observed or predicted values have emerged. One of these protocols requires that both the observation and the prediction must exceed a specified threshold before being considered in the comparison. The other protocol requires that either the observation or the prediction must exceed a specified threshold before being considered in the comparison. This presentation compares the potential effects of applying these two protocols to T&D model assessments. Key words: Atmospheric transport and dispersion, point-to-point protocol, model evaluations