Dear all,

I'm trying to create a geo_em file using the various interpolation options provided by geogrid.

The geo_em file has a resolution of 500m, and the original data (to make LANDUSEF, LU_INDEX and HGT_M field) used to create the geo_em file has a resolution of 100m.

I checked the LU_INDEX variable and found that the interpolation option other than nearest_neighbor did not work.

Of course, LU_INDEX is a categorical variable and it would not be appropriate to use interpolation options other than nearest_neighbor.

However, if use other interpolation options, such as four_pt or sixteen_pt, geogrid must interpolate according to the algorithm of each option, but the execution results are all the same as the nearest_neighbor option.

Meanwhile, when the original data at 1 km resolution were used, each interpolation option appeared to work well.

Is there an algorithm in geogrid/src that compares the original binary data resolution to the model resolution to apply the interpolation option differently?

If not, is there an algorithm that applies appropriate interpolation options when receiving categorical or continuous variables?

Attach the GEOGRID.TBL file and the namelist.wps file that I used to create the geo_em file.

Thank you so much for your help.

I'm trying to create a geo_em file using the various interpolation options provided by geogrid.

The geo_em file has a resolution of 500m, and the original data (to make LANDUSEF, LU_INDEX and HGT_M field) used to create the geo_em file has a resolution of 100m.

I checked the LU_INDEX variable and found that the interpolation option other than nearest_neighbor did not work.

Of course, LU_INDEX is a categorical variable and it would not be appropriate to use interpolation options other than nearest_neighbor.

However, if use other interpolation options, such as four_pt or sixteen_pt, geogrid must interpolate according to the algorithm of each option, but the execution results are all the same as the nearest_neighbor option.

Meanwhile, when the original data at 1 km resolution were used, each interpolation option appeared to work well.

Is there an algorithm in geogrid/src that compares the original binary data resolution to the model resolution to apply the interpolation option differently?

If not, is there an algorithm that applies appropriate interpolation options when receiving categorical or continuous variables?

Attach the GEOGRID.TBL file and the namelist.wps file that I used to create the geo_em file.

Thank you so much for your help.