RSICC CODE PACKAGE CCC-706

1. NAME AND TITLE

MESYST: Code System to Simulate 3D Tracer Dispersion in Atmosphere.

2. CONTRIBUTORS

Conservatoire National des Arts et Metiers, Paris, France through the OECD Nuclear Energy Agency Data Bank, Issy-Les Molineaux, France.

3. CODING LANGUAGE AND COMPUTER

Fortran 77; Cray, MEIKO (C00706MNYWS00).

4. NATURE OF THE PROBLEM SOLVED

MESYST can simulate 3D tracer dispersion in the atmosphere. Three programs are part of this system: CRE_TOPO prepares the terrain data for MESYST. NOABL calculates three-dimensional free divergence windfields over complex terrain. PAS computes tracer concentrations and depositions on a given domain.

The purpose of this work is to develop a reliable simulation tool for pollutant atmospheric dispersion, which gives a realistic approach and allows one to compute the pollutant concentrations over complex terrains with good accuracy. The factional brownian model, which furnishes more accurate concentration values, is introduced to calculate pollutant atmospheric dispersion. The model was validated on SIESTA international experiments.

5. METHOD OF SOLUTION

NOABL - Line Over Relaxation + Special adaptation of GAUSS procedure.

PAS - Monte Carlo Method.

6. RESTRICTIONS OR LIMITATIONS

Mesh size: variable from some meters to some hundreds meters.

Mesh number: variable depending on available real data (some hundreds points on each direction).

7. TYPICAL RUNNING TIME The running times are variable. The efficiencies are good for NOABL for few processors (up to 90%) and decrease with the number of processors. For PAS, the efficiencies are excellent due to the Monte Carlo method. Running times are variable depending on the accuracy required.

8. COMPUTER HARDWARE REQUIREMENTS

MESYST can run on the CRAY T3E parallel machine. Minimal storage requirements are ~3.0 Mbytes. Some of the modules have been run on Sun and MEIKO.

9. COMPUTER SOFTWARE REQUIREMENTS

Fortran and C compilers are required. PVM or MPI is required to run in parallel mode. CRE_TOPO, NOABL, and PAS work under UNICOS/mk 2.0. NOABL also runs under Solaris 2.3 and MEIKO 1.4.08. Machine-specific statements are provided in some makefiles for Cray, DEC Alpha, and AIX. The codes were not tested at either the NEA Data Bank or at RSICC. There is no documentation to guide novice users on installation or execution.

10. REFERENCES

a) Included in hard copy and electronic form:

"User's Guide to the MESYST Program," Conservatoire National des Arts et Metiers, Paris, France (TA-1281: 15/12/1999-27/01/2000) [7 pages describing NORM.INP input file format in file user'sguide.pdf].

R. M. Traci, G. T. Phillips, P. C. Patnaik, "Developing a Site Selection Methodology for Wind Energy Conversion Systems," DOE/ET/20280-3, UC-60 (September 1978) [file DOE_20280_3.pdf].

b) Included in electronic form in the reports subdirectory:

I. Mehillli, "Thèse," Conservatoire National des Arts et Metiers Report (April 2, 1999) [file MESYST THESE.pdf 169 pages in French].

Mastrangelo, V., Mehilli, I., "Parallelization and Implementation of the NOABL Program on Cray T3D, Cray T3E and MEIKO-CS2 Parallel Machines," (June 16, 1997) [file cray_meiko.pdf].

V. Mastrangelo, I. Mehilli, "Parallel and Distributed Development and Simulation of Atmospheric Models," (June 1998) [file parallel.pdf].

V. Mastrangelo and I. Mehilli, "Projet de Parallelisation du Programme Noabl Rapport," (1996) [file proj_parallel.pdf in French].

11. CONTENTS OF CODE PACKAGE

Included in the distribution are the referenced documents and a CD which contains a GNU Unix compressed tar file with the reports, source code, makefiles and sample problems.

12. DATE OF ABSTRACT

January 2002.

KEYWORDS: AIRBORNE; GAUSSIAN PLUME MODEL; MONTE CARLO