How to find the matched variable using misc information in the grib2 file

[Ho-ChunHuang-NOAA]

I have a fcst output grib2 file with two record
1:4846132429:d=2023070206:MASSDEN:8 m above ground:20-21 hour ave fcst:aerosol=Missing:aerosol_size <1e-05
2:4844034447:d=2023070206:MASSDEN:8 m above ground:20-21 hour ave fcst:aerosol=Missing:aerosol_size <2.5e-06

How do I select the variable for PointStats/GridStats based on "aerosol_size <1e-05" and "aerosol_size <2.5e-06" in the config file in addition to

FCST_VAR1_NAME = MASSDEN
FCST_VAR1_LEVELS = Z8

Using
FCST_VAR1_OPTIONS = ??

[MarcelCaron-NOAA]

Would it work for your development problem to match the correct line based on the index/val in the record description (as described here and exemplified in this METplus discussion)?

Otherwise I'm not sure how to select based on the "aerosol_size" threshold in the record info (but would be curious to know!)

[malloryprow]

Maybe some options in here could help? Search "File-format specific settings for the “field” entry:".

[Ho-ChunHuang-NOAA]

Search in DTC Discussion?

[malloryprow]

Ah looks like the link didn't show up quite right. It should now.

[Ho-ChunHuang-NOAA]

Thanks to Marcel's suggestion. I found a way to differentiate two records that has a close grib2 encoding. Please read the links in Marcel's response for detail.

My input fcst grib2 file is

 > wgrib2 rrfs.t12z.prslev.f048.reduced.grib2 -d 1
1:0:d=2023070212:MASSDEN:8 m above ground:48-49 hour ave fcst:aerosol=Missing:aerosol_size <2.5e-06
 > wgrib2 rrfs.t12z.prslev.f048.reduced.grib2 -d 2
2:2609197:d=2023070212:MASSDEN:8 m above ground:48-49 hour ave fcst:aerosol=Missing:aerosol_size <1e-05

I used the tool "degrib2" on the WCOSS2;
(a) find the path to the executable "degrib2"

> module show grib_util
:::::::::::::::::::::::
setenv("DEGRIB2","/apps/ops/prod/libs/intel/19.1.3.304/grib_util/1.2.2/bin/degrib2")
:::::::::::::::::::::::

(b) find the template used in the grib2 file

> /apps/ops/prod/libs/intel/19.1.3.304/grib_util/1.2.2/bin/degrib2 rrfs.t12z.prslev.f048.reduced.grib2

You will find the line of "PRODUCT TEMPLATE" for GRIB MESSAGE 1 and GRIB MESSAGE 2. In my case

GRIB MESSAGE  1  starts at 1
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
PRODUCT TEMPLATE 4. 46: ( PARAMETER = UNKNOWN  0 20 0 )  20 0 65535 0 7 25 0 0 2 0 134 0 0 1 48 103 0 8 255 0 0 2023 7 4 12 0 0 1 0 0 2 1 1 255 0
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
GRIB MESSAGE  2  starts at 2609198
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
PRODUCT TEMPLATE 4. 46: ( PARAMETER = UNKNOWN  0 20 0 )  20 0 65535 0 7 100 0 0 2 0 134 0 0 1 48 103 0 8 255 0 0 2023 7 4 12 0 0 1 0 0 2 1 1 255 0
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

The first number "20" corresponds to index 0. You can find the only difference is index 5, i.e. 25 versus 100.

In addition to the lines in configuration file

FCST_VAR1_NAME = MASSDEN
FCST_VAR1_LEVELS = Z8

For MetPlus finding record 1,
1:0:d=2023070212:MASSDEN:8 m above ground:48-49 hour ave fcst:aerosol=Missing:aerosol_size <2.5e-06

In Configuration file, use
FCST_VAR1_OPTIONS = GRIB2_ipdtmpl_index = [ 5 ]; GRIB2_ipdtmpl_val = [ 25 ];

For MetPlus finding record 2,
2:2609197:d=2023070212:MASSDEN:8 m above ground:48-49 hour ave fcst:aerosol=Missing:aerosol_size <1e-05

In Configuration file, use
CST_VAR1_OPTIONS = GRIB2_ipdtmpl_index = [ 5 ]; GRIB2_ipdtmpl_val = [ 100 ];