Terrain-Responsive Atmospheric Code (TRAC) for plume growth and dispersion in complex terrain

Technical Report · Wed Apr 03 04:00:00 EST 1985

DOI:https://doi.org/10.2172/5984610· OSTI ID:5984610

Hodgin, C R

Use of atmospheric dispersion models to assess pollutant impacts in complex terrain is increasing. However, the temporally and spatially varying wind and turbulence fields in mountainous areas often invalidate the assumptions of straight-line flow and horizontal homogeneity inherent in standard plume models. A dispersion model was recently developed at the Rocky Flats Plant to realistically simulate dispersion processes in complex terrain. The new model treats pollutant releases as a series of overlapping ellipsoidal puffs. The ends of each puff axis are defined by ''tracer'' particles, which are independently advected through the modeled windfield. The puff axes are not, in general, orthogonal. Thus, a puff can develop an arbitrary shape in response to differential diffusion rates, horizontal convergence and divergence, vertical shear, surface reflection, and gravitational settling. The model includes modules for puff transport, diffusion, wet and dry deposition, resuspension, surface roughness effects, ingrowth, decay, and external and internal dosimetry. This report focuses on the simulation of puff growth and shape.

• Research Organization: Rockwell International Corp., Golden, CO (USA). Rocky Flats Plant
• DOE Contract Number: AC04-76DP03533
• OSTI ID: 5984610
• Report Number(s): RFP-3683; ON: DE85010541
• Country of Publication: United States
• Language: English

Related Subjects

500200* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
BOUNDARY LAYERS
COMPLEX TERRAIN
DIFFUSION
EARTH ATMOSPHERE
FLUID FLOW
FUNCTIONS
GAUSS FUNCTION
LAYERS
MATHEMATICAL MODELS
PLUMES
WIND