With or Without EMITIMES?

Topics about the HYSPLIT dispersion model.
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rotendd
Posts: 30
Joined: September 25th, 2016, 12:16 pm
Registered HYSPLIT User: Yes

With or Without EMITIMES?

Post by rotendd »

If the EMITIMES file allows multiple release points as well as respective heights, release areas, and temperatures, what does the model assume these parameters are WITHOUT an EMITIMES file? I'm assuming they default to zero. This this correct?
ariel.stein
Posts: 660
Joined: November 7th, 2012, 3:14 pm
Registered HYSPLIT User: Yes

Re: With or Without EMITIMES?

Post by ariel.stein »

If there is no EMITIMES file, the model will use the information provided in the CONTROL file regarding the emission strength and duration. However, the CONTROL file will not allow you to change the emission strength as the calculation occurs.
rotendd
Posts: 30
Joined: September 25th, 2016, 12:16 pm
Registered HYSPLIT User: Yes

Re: With or Without EMITIMES?

Post by rotendd »

If there are no values for release height, release area, etc. in the CONTROL file, HYSPLIT will still run. In this case, does it use 0m AGL for the release height and 0m^2 for the release area?

Does it assign a heat value (in Watts) to the source even when a value is NOT included in the EMITIMES or CONTROL file?

Thanks again!
ariel.stein
Posts: 660
Joined: November 7th, 2012, 3:14 pm
Registered HYSPLIT User: Yes

Re: With or Without EMITIMES?

Post by ariel.stein »

There should be a release height in the CONTROL file. If not the model will not run.
Here is the description of the field that describes the position in the CONTROL file.
starting location (lat, lon, meters, Opt-4, Opt-5)
Default: 40.0 -90.0 50.0
Position in degrees and decimal (West and South are negative). Height is entered as meters above ground level unless the mean-sea-level flag has been set.
The optional 4th (emission rate - units per hour) and 5th (emission area - square meters) columns on this input line can be used to supersede the value of the emission rate (line 12-2) when multiple sources are defined, otherwise all sources have the same rate as specified on line 12-2. The 5th column defines the virtual size of the source: point sources default to "0".

Only when using the EMITIMES file you can enter the heat value.
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