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Title: Development and validation of a new fallout transport method using variable spectral winds

A new method was developed to incorporate variable winds into fallout transport calculations. The method uses spectral coefficients derived by the National Meteorological Center. Wind vector components are computed with the coefficients along the trajectories of falling particles. Spectral winds are used in the two-step method to compute dose rate on the ground, downwind of a nuclear cloud. First, the hotline is located by computing trajectories of particles from an initial, stabilized cloud, through spectral winds to the ground. The connection of particle landing points is the hotline. Second, dose rate on and around the hotline is computed by analytically smearing the falling cloud's activity along the ground. The feasibility of using spectral winds for fallout particle transport was validated by computing Mount St. Helens ashfall locations and comparing calculations to fallout data. In addition, an ashfall equation was derived for computing volcanic ash mass/area on the ground. Ashfall data and the ashfall equation were used to back-calculate an aggregated particle size distribution for the Mount St. Helens eruption cloud.
Authors:
Publication Date:
OSTI Identifier:
5731690
Resource Type:
Thesis/Dissertation
Resource Relation:
Other Information: Thesis (Ph. D.)
Publisher:
Air Force Institute of Techology,Wright-Patterson AFB, OH
Research Org:
Air Force Inst. of Tech., Wright-Patterson AFB, OH (USA)
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; FALLOUT; DOSE RATES; TRANSPORT THEORY; RADIONUCLIDE MIGRATION; MATHEMATICAL MODELS; ASHES; MT ST HELENS; CASCADE MOUNTAINS; ENVIRONMENTAL TRANSPORT; FEDERAL REGION X; MASS TRANSFER; MOUNTAINS; NORTH AMERICA; RESIDUES; USA; WASHINGTON; 500300* - Environment, Atmospheric- Radioactive Materials Monitoring & Transport- (-1989)