SI3 problem with supercooling
There is an issue in the way we deal with the heat budget in SI3 for forming/melting sea ice. The problem comes from the fact that we need to somehow guess the energy budget in the leads without having information on all the fluxes. And this guess is not so accurate. It is linked to occurence of supercool waters in some specific configurations.
We need to replace these lines in icesbc.F90:
IF( zqld >= 0._wp .AND. at_i(ji,jj) > 0._wp ) THEN
fhld (ji,jj) = rswitch * MAX( 0._wp, ( zqld - zqfr_pos ) * r1_Dt_ice / MAX( at_i(ji,jj), epsi10 ) - qsb_ice_bot(ji,jj) )
qlead(ji,jj) = 0._wp
ELSE
fhld (ji,jj) = 0._wp
qlead(ji,jj) = MIN( 0._wp , zqld - ( qsb_ice_bot(ji,jj) * at_i(ji,jj) * rDt_ice ) - zqfr )
ENDIF
by these ones
IF( ( zqld - zqfr ) < 0._wp .OR. at_i(ji,jj) < epsi10 ) THEN
fhld (ji,jj) = 0._wp
qlead(ji,jj) = MIN( 0._wp , zqld - zqfr )
ELSE
fhld (ji,jj) = rswitch * MAX( 0._wp, ( zqld - zqfr_pos ) * r1_Dt_ice / MAX( at_i(ji,jj), epsi10 ) )
qlead(ji,jj) = 0._wp
ENDIF