Grib2 file band change and run hysplit

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Posts: 10
Joined: February 5th, 2020, 9:24 pm
Registered HYSPLIT User: No

Grib2 file band change and run hysplit

Post by sol »

Dear All

I have being used GFS0p25 data from UCAR NCAR web site for running HYSPLIT Model.
I used api2arl tool to convert Grib2 data to ARL data which need to running HYSPLIT Model. And There wasn't any error while running HYSPLIT.
But recently, I found that Grib2 file's band number have been changed.
(Grib2 file is composed Band data. and each band is indicate each meteorological values such as precipitation, temperature etc.)

Fortunately, I have no error or problem while running HYSPLIT Model with changed GFS0p25 data.
But i wonder that why it is okay to running HYSPLIT Model with GFS0p25 data which's band have been changed.

When converting Grib2 to ARL data, Does HYSPLIT use text code like TPP6 not band number?
(TPP6 is GRIB2 code which means precipitation)

Please let me know.
Posts: 240
Joined: February 8th, 2016, 12:56 pm
Registered HYSPLIT User: Yes

Re: Grib2 file band change and run hysplit

Post by alicec »

The following can be found in Readme_api2arl.txt.
You should be able to look at your api2arl.cfg file to make sure that the correct
variables in the grib file are being used.

The GRIB conversion is defined by the decoding configuration file
which defines the relationship between the grib file variable names,
the ARL packed format variable names, and the units conversion factors.

The default name for this file is api2arl.cfg and if it does not exist,
the file will be created. It can be subsequently edited to define a
customized set of variables. Each user must know which variables are
available in the GRIB input file. The current default configuration
defines the following GRIB variables:
levelType level shortName
pl {hPa} gh t u v r w
sfc 0 sp orog tp lhtfl shtfl uflx vflx dswrf hpbl tcc
sfc 2 2t r

The GRIB messages are scanned and an encoding configuration file is
created (arldata.cfg) that defines the record structure for packing
into the ARL format. Variables defined in api2arl.cfg that are not
found in the GRIB file will not be defined in arldata.cfg. An old file
may be used if the current configuration does not contain all the fields
(e.g. fluxes) and those records are to be filled during another pass
through the program with a different GRIB file. Note that all variables
passed to the packing routines must be defined in this file, but not all
defined variables have to be written during any one pass.
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