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Extracting Particles

Posted: June 18th, 2021, 11:42 am
by mhoecker
Is there a way to convert the binary particle file (PARDUMP) into a format that can be read for post processing (ASCII, or netcdf, or ...). When extracted does that file include particles that have settled? If so does that include the time and location they settle?

Re: Extracting Particles

Posted: June 18th, 2021, 11:55 am
by alicec
There is a utility called par2asc which will convert PARDUMP output to ascii files. You can find it in the exec directory.

Description of the pardump/parinit file is here.
https://www.ready.noaa.gov/hysplitusersguide/S442.htm

There is python code with a class that can read/write pardump files here in pardump.py.
It returns a pandas DataFrame.
https://github.com/noaa-oar-arl/monetio ... tio/models

"Settled" particles will generally not be removed from simulation unless ICHEM=5 is used.
Please see 'deposition and decay" section here.
https://www.ready.noaa.gov/hysplitusers ... deposition
Also tutorial section:
https://www.ready.noaa.gov/documents/Tu ... _dryp.html

If particles are removed from simulation then their position is no longer written to the PARDUMP file.

Re: Extracting Particles

Posted: June 18th, 2021, 12:24 pm
by mhoecker
Can you dump particles more often than 1/hr?

Re: Extracting Particles

Posted: June 18th, 2021, 12:36 pm
by Fantine
If you set ndump < 0, particle positions will be written at each time step.
https://www.ready.noaa.gov/hysplitusersguide/S627.htm
For example, you will get PARDUMP in every minute if you set the time step to 1 minute (delt=1) and ndump=-1 for your run.

Re: Extracting Particles

Posted: April 15th, 2023, 1:40 am
by ascansee
Fantine wrote:
June 18th, 2021, 12:36 pm
If you set ndump < 0, particle positions will be written at each time step.
https://www.ready.noaa.gov/hysplitusersguide/S627.htm
For example, you will get PARDUMP in every minute if you set the time step to 1 minute (delt=1) and ndump=-1 for your run.
I can see how setting ndump < 0 can be helpful in obtaining frequent updates on particle positions. It's great to know that we can get PARDUMP in every minute if we set the time step to 1 minute (delt=1) and ndump=-1 for our run.