need also to apply EXCH to sIceLoad when using just seaice diffusion (+  advection) without seaice-dynamics (useSEAICE=F).
need also to apply EXCH to sIceLoad when using just seaice diffusion (+
 advection) without seaice-dynamics (useSEAICE=F).

altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h