Interpolation of the land-sea mask shows differences due to:

• MIR returns fractional values between 0 and 1 whereas EMOSLIB returns only 0 (sea) or 1 (land)
• the default interpolation method
• the distance computation and selection of nearest points

As a consequence, a small number of points change nature from land to sea or vice versa.

HRES O1280

The land-sea mask has been interpolated from the O1280 octahedral reduced Gaussian source grid to regular lat-lon target grids at different target resolutions using EMOSLIB and MIR. 

• Fewer than 0.05% of grid points are different
• The differences all occur at the coast or close to large lakes and rivers

The plots show the location of the points that differ:

• the blue dots indicate grid points where the LSM field produced with MIR has a land point while that produced with EMOSLIB has sea point
• the red dots indicate points where the LSM field produced with EMOSLIB has a land point while that produced with MIR has sea point