## Advanced / Special Topics / Particle Dump File Format

The concentration configuration menu provides an option to write a model initialization file, which by default is always named "PARDUMP" (for particle dump). This file can be written at regular intervals during the simulation, a convenient way to restart a simulation in case of unexpected failure. To restart the model using the PARDUMP file it is only necessary for the file to be present in the root working directory. If the internal time stamp of the file matches the start time of the simulation, the model will initialize the particle count from the file before emitting new particles according to the emission scenario defined in the control file. The format of the PARDUMP file is given below:

Record #1

- INT*4 Number of particles
- INT*4 Number of pollutants
- INT*4 Time of particle dump (YEAR, MONTH, DAY, HOUR)

Record #2 - Loop to record: Number of particles

- REAL*4 Particle pollutant mass (times the number of pollutants)
- REAL*4 Particle LATITUDE, LONGITUDE, HEIGHT, SIGMA-U,SIGMA-V, SIGMA-X
- INT*4 Particle AGE, DISTRIBUTION, POLLUTANT, METEO-GRID,SORT-INDEX

The "Particle" tab of the "Special File Display" menu brings up a Windows based viewer that shows the particle positions over a map background. The display can be zoomed and otherwise adjusted using the left and right mouse buttons in conjunction with the shift and cntl keys. Help is provided on the screen with the left and right side comments corresponding to the respective mouse button. The particle viewer can also be used to overlay satellite images on the particle positions. More information on this is provided "FTP Satellite Data" help menu.

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