1. NAME AND TITLE
DWNWND: Interactive Gaussian Plume Atmospheric Transport Model.
Oak Ridge National Laboratory, Oak Ridge, Tennessee.
3. CODING LANGUAGE AND COMPUTER
Fortran IV; PDP-10.
4. NATURE OF PROBLEM SOLVED
DWNWND computes sector center-line and average pollutant concentrations for sites downwind
of the source. The code is interactive and prompts the user to input source and atmospheric
parameters. Horizontal and vertical diffusivities are computed based on the user's choice of dispersion
parameters. Eight sets of dispersion parameters are available. Plume tilt and plume depletion are
among the mechanisms considered.
5. METHOD OF SOLUTION
DWNWND is an interactive implementation of the Gaussian plume formulation of atmospheric
transport. Lagrangian interpolation is used to compute equation coefficients based on surface
roughness if the user's choice is Hosker's formulation of the Briggs-Smith parameters. A Simpson's
Rule integration is used to calculate plume depletion.
6. RESTRICTIONS OR LIMITATIONS
7. TYPICAL RUNNING TIME
DWNWND executes a typical problem run in approximately 1 second.
8. COMPUTER HARDWARE REQUIREMENTS
DWNWND is operable on the PDP-10 computer. No auxiliary storage is required.
9. COMPUTER SOFTWARE REQUIREMENTS
A Fortran IV compiler is required.
D. E. Fields and C. W. Miller, "User's Manual for DWNWND An Interactive Gaussian Plume
Atmospheric Transport Model with Eight Dispersion Parameter Options," ORNL/TM-6874 (May
11. CONTENTS OF CODE PACKAGE
Included are the referenced document and one (1.2MB) DOS diskette which contains the source
12. DATE OF ABSTRACT
February 1982; revised February 1983.
KEYWORDS: AIR-GROUND INTERFACE; AIRBORNE; NUCLIDE TRANSPORT; GAUSSIAN PLUME MODEL; ENVIRONMENTAL DOSE; ON-LINE; INTERACTIVE; FALLOUT; RADIOLOGICAL SAFETY