Accession Number:

AD0600447

Title:

THE INFLUENCE OF LOCAL WINDS ON FALLOUT

Descriptive Note:

Progress rept. no. 1, 1 July-31 Dec 1963

Corporate Author:

TRAVELERS RESEARCH CENTER INC HARTFORD CT

Report Date:

1963-12-31

Pagination or Media Count:

42.0

Abstract:

Model local circulations are discussed with regard to their influence on the disposition of airborne particles in a non-precipitating, nondiffusive atmosphere. Two-dimensional vertical circulations like the sea breeze along a straight coast, or like the circulations near mountain ranges, when steady- state, principally affect the time of establishment of a pattern and not its shape or the ultimate patterns of the total accumulations at the ground. When such calculations intensify or decay during the passage of fallout through them, both the duration and onset time of fallout at ground locations can be affected, with associated local changes of total accumulation. Three dimensional local circulations affect the place of deposit of airborne particles and the time of their deposition. Circulations confined to the horizontal plane can affect the place of deposit and shape of a fallout pattern, but vertical air currents must occur to change the time of its establishment. Three dimensional divergence accompanying vertical currents in the real compressible atmosphere significantly increases local concentrations in only those cases where updrafts are about equal to particle fall speeds in such cases, the role of diffusion should be simultaneously considered. The influence of local circulations, in any case, is greatest with respect to the smallest slowest falling particles.

Subject Categories:

  • Radiation Pollution and Control

Distribution Statement:

APPROVED FOR PUBLIC RELEASE