One long-term problem with EMOSLIB is that there is an inconsistency between interpolated values of the land-sea mask and sea-surface temperature. This can lead to:
- land-points (i.e., points where the interpolated LSM >= 0.5) with a sea-surface temperature
- sea-points (i.e., points where the interpolated LSM < 0.5) without a sea surface temperature
This is demonstrated in the figures below for the LSM and SST from ERA-Interim interpolated to a 0.75x0.75 regular lat-lon grid. The figure on the left shows the results using EMOSLIB with the default (bilinear) interpolation method and that on the right those using a nearest neighbour method.
ERA Interim (N128) interpolated with EMOSLIB to a 0.75x0.75 regular lat-lon grid using the default interpolation method (bilinear) and land-sea mask processing
Globally, in total, there are:
| ERA Interim (N128) interpolated with EMOSLIB to a 0.75x0.75 regular lat-lon grid using the nearest neighbour and default land-sea mask processing
Globally, in total, there are:
|
Repeating the interpolation with MIR produces the following results, again with the figure on the left showing the results with the default (linear) interpolation method and that on the right those using a nearest neighbour method.
ERA Interim (N128) interpolated with MIR to a 0.75x0.75 regular lat-lon grid using the default interpolation method (linear) and land-sea mask processing
Globally, in total, there are:
| ERA Interim (N128) interpolated with MIR to a 0.75x0.75 regular lat-lon grid using the nearest-neighbour method (linear) and land-sea mask processing
Globally, in total, there are:
|
Using the nearest neighbour method with MIR produces a sea-surface temperature field consistent with the land-sea mask