Mass Backward Trajectories in Hysplit or Matlab

Topics about the trajectory clustering program for HYSPLIT.
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Cggc
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Joined: March 28th, 2018, 1:21 am
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Mass Backward Trajectories in Hysplit or Matlab

Post by Cggc » March 28th, 2018, 1:28 am

I am needing to create back trajectories at three different height levels every 6 hours, every day, from 1990-2017 (or as far as I can go) and then compare these to historical data going back to the 1940's. I have started creating these trajectories and getting the text files, but there must be an easier way than inputting each month for each year. Doing this manually will take several weeks and I would really like to speed up the process.

It would also be helpful to combine the text files. I have tried doing this in HYSPLIT, but it never seems to work. Does anyone know how to do this?

Does anyone have a MATLAB script that can run HYSPLIT back trajectories automatically? Even just creating the text files?

Or, does anyone know how to do this in HYSPLIT?

Thanks in advance. And I am sorry if this question has been answered somewhere before. Nothing useful turned up with a general search of the forum.

barbara.stunder
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Joined: November 9th, 2012, 4:23 pm
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Re: Mass Backward Trajectories in Hysplit or Matlab

Post by barbara.stunder » March 28th, 2018, 8:58 am

To automate the trajectories, you are right that a script is needed, however I don't use Matlab.

The Run Daily is running a TCL script on a PC (c:\hysplit4\guicode\auto_traj.tcl). A month loop could be added to it, but make sure the appropriate meteorology files are in the CONTROL file.

The c:\hysplit4\examples\scripts has batch, tcl, and unix subdirectories with template scripts.

There are also links near the top of the page in each Tutorial section to both batch files and linux scripts.
https://ready.arl.noaa.gov/HYSPLIT_Tutorials.php

There is a program in the exec directory 'trajmerg' that merges trajectory endpoints files.

Cggc
Posts: 8
Joined: March 28th, 2018, 1:21 am
Registered HYSPLIT User: Yes

Re: Mass Backward Trajectories in Hysplit or Matlab

Post by Cggc » April 3rd, 2018, 7:12 pm

Thank you for trying to help, but I cannot get the Tutorial\batch file to run. I have put the extracted zip files in both locations, my C drive and under my user files (thanks Windows for making this a necessity). Still no luck.

Any suggestions?

Cggc
Posts: 8
Joined: March 28th, 2018, 1:21 am
Registered HYSPLIT User: Yes

Re: Mass Backward Trajectories in Hysplit or Matlab

Post by Cggc » April 3rd, 2018, 9:14 pm

Thank you for directing me to the Tutorials. I have learned a lot, but not what I actually need to do. Can you help me with the basics of this loop? If all I get are the Tdump files, then that is a start. At least in that regard, I can analyze where my trajectories are coming from most.

barbara.stunder
Posts: 272
Joined: November 9th, 2012, 4:23 pm
Registered HYSPLIT User: Yes

Re: Mass Backward Trajectories in Hysplit or Matlab

Post by barbara.stunder » April 4th, 2018, 8:30 am

Use this batch file from the Frequency Analysis section of the Tutorial, get it to work, then make changes for your dates, locations, etc:
https://www.ready.noaa.gov/documents/Tu ... j_freq.bat

That file is in c:\Tutorial\batch. In Windows File Explorer, double-click on it to run it. It will open the Windows Command Prompt, show a lot of output in the Command Prompt window, then automatically open the postscript graphic. The trajectory output files are named fdump* and are in c:\working. The graphic is the file concplot.ps (Trajectory frequency plots are created with the concentration plotting program concplot.)

Open traj_freq.bat in Notepad. This is what it does:
WRK=C:
PGM=c:\hysplit
cd c:\working
creates ASCDATA.CFG file
defines year, month, trajectory start location, run duration, model top, and gives directory, filename of the meteorology file
deletes any fdump* files
loop through days
loop through hours
creates the CONTROL file
run the trajectory program (c:\hysplit4\exec\hyts_std)
ends the hour, date loops
runs the trajectory frequency program and makes the plot

Then change the lat, lon for your location, edit the height, add a month loop, etc. There is a limit of 12 meteorology files.

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