Address interpolation issue in point2grid when mapping to HRRR domain

[michelleharrold]

Describe the Enhancement

When running the point2grid tool to remap GOES 16/17 data to the HRRR grid, circular artifacts appear. This behavior is not seen when remapping to a coarser grid such as the GFS grid. In addition, Chris Rozoff has Python code which performs similarly to point2grid, and this code does not produce circular artifacts (therefore, it does not appear to be a data input issue).

We are preforming testing on Cheyenne using the met-9.0 module. Below is the command we are executing to run point2grid on the GOES data to translate it to the HRRR grid (data files too big to attach). The resultant output from this command yields circular artifacts.

point2grid /gpfs/fs1/p/ral/jntp/AF/cloud_vx/goes_data/level2/abi_tb_fd_2020070300_C13_G16.nc /glade/p/ral/jntp/AF/cloud_vx/model_data/HRRR/2020060800-05/hrrr.t00z.wrfprsf01.grib2 test_hrrr.nc -field 'name="tb"; level="(,)";' -v 4

For reference, Chris' Python regridding code is also available on Cheyenne: /gpfs/fs1/p/ral/jntp/AF/cloud_vx/goes_data/regridded/regrid_hrrr.py

Time Estimate

?

Relevant Deadlines

No hard deadline, but the AF team would optimally use point2grid over the Python code listed above in order to deliver a full MET-based workflow for cloud evaluation. PoP ends 31 Jan 2021, but majority of work is being done now.

Funding Source

AF V&V 2712221 (but please discuss any charging ahead of time with Michelle Harrold)

Define the Metadata

Assignee

• [x] Select engineer(s) or no engineer required: John Halley Gotway or Howard Soh
• [x] Select scientist(s) or no scientist required: Michelle Harrold, Jamie Wolff, or Chris Rozoff

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Consider the impact to the other METplus components.

• [ ] METplus, MET, METdb, METviewer, METexpress, METcalcpy, METplotpy

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[hsoh-u]

tb_g16 = griddata(points, values, (lon_fv3, lat_fv3), method = 'linear')

This might be caused by the different interpolation method. The "linear" interpolation would fill the gab. I wonder the python version produces the similar output by using min/max/avg interpolation method

[hsoh-u]

MET:

• regrid from 5424 5424 (29,419,776 cells) to 1799 1059 (1,905,141 cells)
• 2,281,341 cells (out of 29,419,776 cell were mapped to TO_GRID (7.75445%)
• Interpolation method: UW_MEAN
• There are many missing values after regridding

The python code:

• regrid to 1411 by 3110 (4,388,210 cells from GOES_16_HRRR.nc)
• interpolation method: linear