metgrid - SST interpolation artifacts

[okurum]

Hi all,

I am currently having an issue with the met_em* files generated by metgrid.exe

I am interpolating the SST (from ERA5) to my domain but I am seeing some interpolation artifacts that I can't explain.
I played with the options in METGRID.TBL.

First try was:

name=SST
        interp_option=sixteen_pt+four_pt+wt_average_4pt+wt_average_16pt+search
        masked=land
        interp_mask=LANDSEA(1)
        missing_value=-1.E30
        fill_missing=0.
        flag_in_output=FLAG_SST

Second try:

name=SST
        interp_option=nearest_neighbor
        masked=land
        interp_mask=LANDSEA(1)
        missing_value=-1.E30
        fill_missing=0.
        flag_in_output=FLAG_SST

Left panel is the source data used: ERA5 grib file. Plots are SST in K color range: 300-305K


can you please advise me on what may be wrong here?
Cheers

 

[Ming Chen]

Would you please clarify the difference between the left and right panels of the first plot you attached?
Also,when you processed the ERA5 data, did you include the invariant data?
Please take a look at this post and see whether it is helpful:
https://forum.mmm.ucar.edu/phpBB3/viewtopic.php?f=75&t=9714