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How to create new greenfrac binary file?

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I am trying to run WRF with new greenness fraction calculated by MODIS NDVI. Actually, the size of single binary in folder greenfrac_fpar_modis(17.28M) is twelve times larger than that in landuse or topo(1.44M) in the default directory WRF3.9/DATA/WPS_GEOG/geog/. So I naturally guess the former contained twelve monthes data and am wondering if it has twelve float fields.

1) Can anyone provide a input file(table, shapefile or raster) which contains fields information(name, type and length) and can be converted into binary in greenfrac. It will be helpful for new greenfrac binary preparation.
2) I am confused by variable "wordsize" in index. Does it means field length?
3) I input a new single month binary into WRF, the result is weird, full details are given in attachments.

Any details will be available!



  • greenfrac-July.jpg
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  • greenfrac-July1.jpg
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The greenfrac data in default WPS static datasets includes 12-month data. It is processed in REAL program to obtain greenfrac for the specific time of model integration,

"wordsize" is an integer giving the number of bytes used to represent the value of each grid point in the data files. I would suggest you set it to be the same as that in the default WPS dataset

You need to either provide 12-month data, or modify the source code if you only have 1-month data to make WRF correctly ingests your data.
Dear Chen,

Thanks for your helpful reply !
I had tried to do some work according to your guidance. However, puzzles still remain.

I try to read greenfrac binary using NCL method "fbindirread", then realise it just possesses one field and contains 12-month data. My greenfrac files can be converted into single binary, do you know by which means can they be integrated?

I am not sure the specific meaning of "REAL program", could you please explain it(real.F,wrfinput,real.exe)?
Because my simulation is mainly conducted in April, July and November separately, so I want they are exclusive in certain period to ingest into simulation. Could you please give me some details?

Please forgive any offense.

9 Jan,2019
I am not sure whether you can easily create greenfrac file using NCL. This is because WPS has special format for geogrid binary data. Please take a look at the website here for detailed description:
I would suggest you follow the instruction in the above website to create the data.

REAL is the program (you can find real.exe located at /WRF/main/) in WRF to create initial and boundary conditions. The most important code for REAL is module_initialize_real.F (located at /WRF/dyn_em/), which is the code to process static and meteorological data, conduct adjustment, etc.