SST in the model initial files

The OpenIFS initial file that contains the sea-surface temperature (SST) is the ICMCL file. The SST is represented as the parameter "soil temperature layer 1" (top soil layer 1-7cm), grib parameter STL1, grib code 139 where the land-sea mask defines a sea gridpoint. STL1 also contains the representation of the sea-ice field, grib parameter CI.

Manipulating the SST for the model involves changes the STL1 field but masking should be used to maintain the values over the land points.

The land-sea mask, grib parameter LSM, grib code 172, is contained in the ICMGG*INIT file. Values of lsm >= 0.5 are treated as land points, values < 0.5 are treated as sea-points.