Temporal Changes in Horizontal Diffusion Parameters of a Single Nuclear Debris Cloud

1 June 1972

journal article
Published by American Meteorological Society in Journal of Applied Meteorology

Vol. 11 (4) , 670-673
https://doi.org/10.1175/1520-0450(1972)011<0670:tcihdp>2.0.co;2

Abstract

An evaluation is made of the variations of σ_y and K_H over a 70-hr period as derived from analyses of radiological and meteorological data collected during extensive aerial sampling of a single nuclear debris cloud. These data reveal that for t10 hr, σ_y∝T^0.5 and K_H≈constant; however, for 1<ty∝T^1.2 and K_H≈σ^1.17_y.A constant-diffusivity model for the Ekman layer, developed by Csanady, is assessed. The model yields close approximations to σ_y through the period of “shear-induced” diffusion between 1 and 10 hr after detonation. In both cases the constant-diffusivity model is highly dependent on U²_g

Keywords

DATA COLLECTION

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