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Initialization of MPAS regional run with NARR data

K

kgurer777

New member
Hello,

I would like to initialize MPAS regional model using NARR data for 2023. I downloaded 3-hourly NARR analysis files and constant field file rr-fixed.grb. During the creation of MPAS intialization files, WPS looks for "LANDSEA" field, which doesn't exist within NARR grib1 files anymore. That field is located within rr-fixed.grb file. If I recall correctly, the constant fields like "LANDSEA" used to be within NARR grib2 data. Now, grib1 data format is adopted, "LAND" field name was used instead of "LANDSEA", and these constant fields are kept within rr-fixed.grb file. I need to either change the "LAND" field name into "LANDSEA" and concatenate that fixed field into the first "FILE:yyyy-mm-dy_hr", or modify the source code within ungrib/src/rrpr.F by replacing "LANDSEA" variable. I find the latter option as risky as other source files may also need to be altered and any additional re-compilation issues may come up.

How can I provide LANDSEA variable into the initialization files of MPAS?

Thank you.
 
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I don't think the name change from 'LANDSEA' to 'LAND' could be an issue. When you run ungrib.exe to extract land mask information, you can always specify 'metgrid Name' to 'LANDSEA', and this variable should correspond to GRIB1 parameters of 'LAND' in your NARR.

ungrib.exe will yield intermediate files that contain the variable 'LANDSEA', which is the variable 'LAND' in your NARR.

Hope this is helpful for you. Please let me know if you have more questions.
 
Thank you for your answer Ming. I thought I need use "intermediate" files "FILE:yyyy-mm-dy_hr" and "SST:yyyy-mm-dy_hr", not "metgrid" netcdf files via WPS for the initialization of MPAS in namelist.init_atmosphere file:

config_met_prefix = '/data/mmb/raqm/work/users/kgurer/new.mpas.runs/WPS-4.6.0/2023/narr/Jan/FILE'
config_sfc_prefix = '/data/mmb/raqm/work/users/kgurer/new.mpas.runs/WPS-4.6.0/2023/narr/Jan/SST'

Let me try your suggestion. Thank you again.
 
I didn't mean that you need metgrid files. What I am talking of is the Vtable, which specifies 'metgrid Name' for variables extracted from the input GRIB format datafile. The specifed "metgrid Name" is the name of the variable shown in intermediate file, and MPAS will read the variable, producing initial condition for subsequent MPAS run.

Please let me know if you have any questions regarding this issue.
 
True, Ming. Thanks for the update of the information. First, I got confused by the name "metgrid" when you mentioned. Then I realized my error. In addition, I also realized that the metgrid name within Vtable file is not what is expected to be found within grib files for variable names, but the names to the variables that we can assign to. Then, by executing ungrib, I passed that error stage.

However, this time, I got another error during the creation of initialization file:

ERROR: You have not called map_set for this projection
CRITICAL ERROR: LATLON_TO_IJ

Where do I assign this parameter? When I look at the output of FILE:2022-12-31_00, it states the projection is set to 3 and LAMBERT CONFORMAL

I attached the log.init_atmosphere.*, namelist.init_atmosphere, namelist.wps and output of FILE:2022-12-31_00 files.

Thank you.
 

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  • log_namelist_output.zip
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If I remember correctly, NARR data are on lambert map projection. Let me know if I am wrong.

Currently MPAS only accepts data on Gaussian or LAT-LON grids. It doesn't process data on lambert map projection. I believe this is the reason you got the error message shown in the log file.

I suggest that you switch to other data products such as GFS or ERA5.
 
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