Thin Plume

Topics about the HYSPLIT dispersion model.
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Smaug
Posts: 55
Joined: July 1st, 2017, 8:28 am
Registered HYSPLIT User: No

Thin Plume

Post by Smaug » June 28th, 2019, 2:31 pm

Hello,

I am running Hysplit for a single site profile and I am getting, in some instances, a very thin plume that is being advected but is not growing laterally as you would think it should do due to dispersion/turbulence. I am trying to understand why and my first guess is that HYSPLIT will not interpolate the data records and will choose the data record that it is temporally closest to. I have tried changing the pasquill stability but this has made little difference.


Thanks

barbara.stunder
Posts: 334
Joined: November 9th, 2012, 4:23 pm
Registered HYSPLIT User: Yes

Re: Thin Plume

Post by barbara.stunder » July 1st, 2019, 8:15 am

Where/how are you running HYSPLIT, and with what meteorology? The Pasquil stability is not an input to HYSPLIT.

Smaug
Posts: 55
Joined: July 1st, 2017, 8:28 am
Registered HYSPLIT User: No

Re: Thin Plume

Post by Smaug » July 1st, 2019, 9:01 am

I am running HYSPLIT on Linux using a the srf2arl as I am using site measurement. This executable needs a Pasquil stability among other variables including wind direction, wind speed, boundary layer depth, relative humidity, surface pressure, mean sea level pressure and time.

barbara.stunder
Posts: 334
Joined: November 9th, 2012, 4:23 pm
Registered HYSPLIT User: Yes

Re: Thin Plume

Post by barbara.stunder » July 2nd, 2019, 8:55 am

I meant that the Pasquill stability class is not input to the HYSPLIT dispersion model. You are entering the Pasquill stability, along with meteorology observations to create a gridded meteorology file for input to the HYSPLIT dispersion model. Then with that meteorology, getting the thin plume. The question is "How closely does the meteorology you created match the actuality of the atmosphere?". This is of course difficult to answer.

Here are some other options: Run this case using instead some of the archived data described at https://ready.arl.noaa.gov/archives.php? Can you run the dispersion with two meteorology files - both the file you created for the time period over which the meteorology remains constant, and with one of the archived files? Or can your observations be included in a WRF run, and converted to HYSPLIT-format?

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