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Interpolation of 2m temperature or 10m wind over or near a coastline currently uses the land-sea mask to decide the whether the four surrounding model grid points are land or sea points.  This determines whether the interpolated value should be regarded as a land or sea point.  In this way there will be no undesired smoothing of gradients along coastlines.  There can be systematic differences between ENS ( and HRES), with strong gradients along coasts, near small islands, or in mountainous regions.  There were historical reasons, related to resolution, for using the land-sea mask in interpolation procedures.  There is much less need for this now that the IFS model resolution is much higher.  The interpolation package MIR does not use a land-sea mask when interpolating data to another resolution.  This is because the data will already have taken the land-sea mask into account during processing at the appropriate resolution of the IFS.   However, interpretation of the IFS land-sea mask by MIR shows a few points change in nature from land to sea or sea to land.  This very slightly modifies the display of geographical features. 

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