Looping a Complex Emission

[rotendd]

First of all, thank you for all of your continued help! I have two (hopefully quick) questions:

1.) In the working directory, I have a CONTROL file, EMITIMES file, and an ASCDATA.CFG data file. I am using an R script to loop through every day of the year 2012 (by rebuilding the CONTROL and EMITIMES files) with 3 point sources (lat, lon, height(AGL), rate, area, heat). Am I correct in thinking that the hycs_std.exe file will automatically use the CONTROL file AS WELL AS the EMITIMES file? Or do I need to run an extra *.exe file to combine them?

2.) Also, I have read a few forum posts pertaining to a hycm_std.exe file. What are the differences in the hycm and the hycs files? Should I consider using the hycm file?

Thanks again!

[ariel.stein]

1) You will need to edit a file called SETUP.CFG that should be located in your working directory (if not copy CONC.CFG to SETUP.CFG) and add a line with the following:
EFILE='EMITIMES',

That will tell the model to use the EMITIMES file you created.

2) hycm_std.exe corresponds to the multiple processor version of the model. You can call the executable using mpirun and the model will use a number of processors to distribute the calculation of the transport and dispersion of the lagrangian particles.
To call this program you should use an expression like:
mpirun -np 12 ../exec/hycm_std.exe
this example uses 12 processors.

[rotendd]

Thanks! Is there any documentation that explains how the hycs_std.exe file incorporates both the EMITIMES file and the CONTROL file versus when it is run with only the CONTROL file?

[ariel.stein]

Please check the following link from our online training material describing the use of the EMITIMES:
https://www.ready.noaa.gov/documents/Tu ... _emit.html

[rotendd]

Once again, I have another question. My specific project involves the modeling of the dispersion from a large stack. Using the control file, I can input the obvious parameters (lat, lon, height(AGL), rate(mass/hr), area(m^2)) but all of the data pertaining to the stack of interest contains only exit velocity and exhaust temperature. I am new to dispersion modeling so I do not know if there is a "rule of thumb" for calculating the heat parameter from known parameters. I have looked over the volcano example using the EMITIMES file but it doesn't seem to address the inclusion of heat (emitimes file from example: https://www.ready.noaa.gov/documents/Tu ... s_volc.txt). I have also done some searching online for a definitive example of how this value can be incorporated but can't seem to find anything.

My current logic is to use dQ/s=(mass/s)*c*dT (where dT is the temperature difference between the exhaust and the ambient air). My main question is: is this the method that the HYSPLIT/Briggs model "expects" or does the emission heat correspond to a parameter (or combination of parameters) found in the Briggs equation?

In summary, in the emission file GUI, how is the model expecting the "heat release for plume rise" be calculated?

Thanks again!

[glenn.rolph]

You can enter the heat release for the plume rise calculation that HYSPLIT will perform using the Briggs equation by enter the heat release (watts) into the EMITIMES file immediately after the emission area. A non-zero value for the heat release will cause HYSPLIT to calculate the release height based on the Briggs equation and therefore it will ignore the previous release height.

More details can be found in the HELP document (\hysplit4\html\S417.htm) and in this tutorial for a fire:

http://www.ready.noaa.gov/documents/Tut ... smoke.html

Glenn