Conversion for GEOS

Post questions and find resources to convert meteorological data into a format HYSPLIT can read.
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acollow
Posts: 7
Joined: November 9th, 2017, 12:13 pm
Registered HYSPLIT User: Yes

Conversion for GEOS

Post by acollow » February 9th, 2018, 10:43 am

Has anyone modified the codes in /data2arl/mer2arl to use the GEOS FP data instead of MERRA-2? There are some differences in the data including the horizontal resolution and single time step for each file, aside from where the data needs to be downloaded from (https://portal.nccs.nasa.gov/datashare/ ... ub/fp/das/). However, the file collections and variables should be the same. It would be great to have this as an option for HYSPLIT since it is a more advanced version of the model and assimilation!

Thanks,
Allie

acollow
Posts: 7
Joined: November 9th, 2017, 12:13 pm
Registered HYSPLIT User: Yes

Re: Conversion for GEOS

Post by acollow » February 16th, 2018, 3:00 pm

I made some modifications to the codes in /data2arl/mer2arl, as documented below, so that GEOS fp could be used. I was able to create an ARL file without any errors, which opened up using "check file" in the meteorology tab with the GUI (though the x dimension in the header was cutoff to reflect 115 instead of 1152). When running HYSPLIT however, I did get an error with the program stopping at line 301 of runset.f, which is "READ(IUNIT,'(A)')FILE(KG,KT)%DIR". What should I be checking for in my ARL file to make sure whatever that line is looking for ended up in the input file properly?

Thanks,
Allie



CHANGES MADE
-METGRID.CFG: updated ref lon and lat to 0.25 and 0.3125 as well as number of x and y grid points (1152 x 721)
-MERDATA.CFG and cfgvar.f: changed variable name to SWGNT for net surface sw radiative flux since tavg1_2d_int_Nx is not available; also changed PRECTOTCORR to PRECTOT
-mer2arl.f: changed int to rad on line 292, modified file names to reflect GEOS, switched to inst3_3d_asm_Nv since PL is not included in the tavg file

NO CHANGES MADE TO:
-cfgrec.f
-get2dv.f, get3dv.f, get4dv.f, getdim.f
-intp2d.f
-METLAYS.INC
-setndx.f, setvar.f

OTHER NOTES
-prefix (ex/MERRA2_400) is defined in csh script that runs the code

MODIFATIONS TO DOWNLOADED FILES
-use ncrcat to concatenate to daily files
-after, in matlab, use ncwrite with t=30:60:1440 and t=30:180:1440 to write the time steps
in the file

Fantine
Posts: 78
Joined: November 8th, 2012, 3:41 pm

Re: Conversion for GEOS

Post by Fantine » February 27th, 2018, 10:23 am

The runset is a subroutine reading the CONTROL file, not reading your ARL formatted file yet at that point. Would you please attach the CONTROL file that we can help your diagnose what caused error?

Thanks for making the conversion program for GEOS fp. We would like to include that others can use it to convert this dataset for their applications.

acollow
Posts: 7
Joined: November 9th, 2017, 12:13 pm
Registered HYSPLIT User: Yes

Re: Conversion for GEOS

Post by acollow » October 24th, 2019, 12:04 pm

It has been a while but I am beginning to look into using GEOS with HYSPLIT again. I have been able to run my modified code that converts GEOS data to ARL however I noticed when running HYSPLIT, it crashes whenever the trajectory would cross the prime meridian. My thought is that the input data is -180 to 180 longitude but data2arl thinks it is 0 to 360. I changed GRIDS(11) in cfgrec.f to -180 but that doesn't seem to be reflected when I run the check file program as shown below. Would anything else need to change? Thanks!

Pole pnt lat/lon : 90.0000 359.6870
Reference lat/lon: 0.2500 0.3120
Grid size (km) : 27.7996
Orientation : 0.0000
Tang Lat / Cone : 0.0000
Synch pnt x,y : 1.0000 1.0000
Synch pnt lat/lon: -90.0000 0.0000

Fantine
Posts: 78
Joined: November 8th, 2012, 3:41 pm

Re: Conversion for GEOS

Post by Fantine » October 30th, 2019, 4:52 pm

The program is using an existing CFG file. You need to delete it before running the updated executable. Otherwise, the program will use the old CFG file instead of creating a new one. Make sure the GRIDS(10) and GRIDS(11) are lat/lon coordinates of the 1,1 grid point.
Ps. for the mer2arl program, the data array is converted from 0-360 system.

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