NESC0591 PLETHS

1. NAME OR DESIGNATION OF PROGRAM:  PLETHS

3. DESCRIPTION OF PROBLEM OR FUNCTION

PLETHS is a time-sharing isopleth-area program for determining ground-level areas of high pollutant concentration downwind of a single source of emission. These elliptical areas are enclosed by isopleths of constant concentration produced by continuous pollutant emissions from one smoke stack or ground source, or from a closely associated group of  single sources. Stack height, weather conditions, and source emission rate are typed in and the program calculates and describes  the high pollution areas enclosed by isopleths.

4. METHOD OF SOLUTION

Concentrations for each point of a square grid  are calculated by means of the plume model for atmospheric dispersion or (for low wind speeds) the puff model.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

Calculations can be  performed for any (nonreacting) gas or particulate matter. The resulting concentrations and isopleths are in parts per million (for gases of given molecular weight) or in micrograms per cubic meter (for any pollutant).

6. TYPICAL RUNNING TIME

Less than a minute is required with average connect time about 15 to 20 minutes.

7. UNUSUAL FEATURES OF THE PROGRAM

The particular advantage of the time-sharing program is that isopleths can be calculated for any combination of source strength and isopleth level, as well as any combination of wind speed, stability, and other meteorological conditions. Any book of tables is necessarily limited by size to a small set of cases.

8. RELATED AND AUXILIARY PROGRAMS

The time-sharing program is based on the isopleth-area code described in reference 1. This code also formed the nucleus of the PUFF code associated with the APICS system, reference 2.

10. REFERENCES

L. A. Conley, E. J. Croke, A. S. Kennedy, R. F. King,
J.  E. Norco,  J. J.  Roberts, A.  D.  Rossin, and  T. D.  Wolsko,
Isopleth-Area Tables, ANL/ES-8, October 1971.
             J. J. Roberts, Editor,  Chicago Air Pollution Systems
Analysis Program:  Final Report, ANL/ES-CC-009, February 1971.
             Richard F. King,  Time-Sharing Isopleth-Area Program,
ANL/ES-13, September 1972.

11. MACHINE REQUIREMENTS

Code lengths are: source, about 22,500 bytes, object, about 13,000 bytes, 3-bytes per 24-bit word.

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:  GSA Time-Sharing  System.

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS:

15. NAME AND ESTABLISHMENT OF AUTHOR

                 Richard F. King
                 Energy and Environmental Systems Division
                 Argonne National Laboratory
                 9700 South Cass Avenue
                 Argonne, Illinois  60439

File name	File description	Records
NESC0591_01.001	INFORMATION	7
NESC0591_01.002	SOURCE PROGRAM (F4) EBCDIC	717
NESC0591_01.003	SAMPLE PROBLEM INPUT DATA	25
NESC0591_01.004	SAMPLE PROBLEM PRINTED OUTPUT	125