Accession Number:

ADA237024

Title:

Target Area Operating Conditions Dust Lofting from Natural Surfaces

Descriptive Note:

Technical rept. 29 Sep 1987-29 Apr 1990

Corporate Author:

PACIFIC-SIERRA RESEARCH CORP LOS ANGELES CA

Personal Author(s):

Report Date:

1991-06-01

Pagination or Media Count:

40.0

Abstract:

We explore how variations in soil type, vegetation cover, and climatic conditions influence the sweep up mass in target regions. A simple dust sweepupsuspension model, appropriate for the high wind speeds associated with nuclear blast waves, is developed to depend explicitly on the threshold shear velocity required to initiate dust lofting. Given an analytic driver for the positive phase free stream wind speed versus ground range and time, sweepup masses for a wide range of surface types and conditions are calculated. We find that for an airburst at SHOB 500 ftcu.rt.kt, the sweepup mass can be reduced to near zero if the surface is covered with tall grass or a mature small grain crop. For burts over loose, unvegetated sand, sweepup efficiencies are nearly six times greater than for a typical Nevada Test Site surface. For a lower altitude airburst SHOB 50 ftcu.rt.kt, a somewhat smaller variation between these extremes is predicted e.g., scouring is possible even over grass or cropland. The yield dependence of sweepup mass and the surface area scoured by the blast winds is also explored. The results indicate that the net dust injection from a nuclear laydown can vary significantly within individual target areas and may be a strong function of season-especially in agricultural regions.

Subject Categories:

  • Nuclear Weapons

Distribution Statement:

APPROVED FOR PUBLIC RELEASE