LOMPOC Valley Diffusion Experiment Analysis - Mt. Iron Comparison and Two ZoneConvective Scaling Model

摘要

LVDE(Lompoc Valley Diffusion Experiment) was conducted Aug 1989 to assess thepotential risk of gaseous releases from the Hypergolic Stockpile and Storage Facility at Vandenberg AFB. Results of the LVDE are compared to the predictive equations of the Mt. Iron Diffusion Tests, conducted at Vandenberg in the 1960's. The Mt. Iron equation parameterizes diffusion with on-base meteorological tower input data. Regression techniques similar to those of Mt. Iron are used in this comparison, resulting in LVDE equations which use the same meteorological data as input. Instantaneous and time averaged centerline concentrations, in both flat and complex terrain are analyzed. For all cases LVDE concentrations are shown to decrease with range less rapidly than the Mt. Iron equation predicts. We suggest that this bias is due to gravitational and/or scavenging losses of the tracer material used in Mt. Iron. A 'two-zone' convective scaling equation is developed which diffuses the plume differently in cloud covered and clear sky portions of the domain. The method is shown to be superior to homogeneous convective scaling equations, and comparable to a statistical approach based on the plume measurements. While the method works for maximum concentration predictions, it fails for plume width and crosswind integrated concentration for X > 6.