LIM-2 - bulk CLIO bug in surface ice stress (sbcblk_clio.F90)

[gm]

In clio bulk formulae, the air-ice stress is deduced from the air-sea stress by applying a ratio cai / cao,
BUT only in case of 'C'-grid ice (LIM-3) not for LIM-2 ('B'-grid case).

change :

      SELECT CASE( cd_grid )
      CASE( 'C' )                          ! C-grid ice dynamics
         ! Change from wind speed to wind stress over OCEAN (cao is used)
         zcoef = cai / cao 
!CDIR COLLAPSE
         DO jj = 1 , jpj
            DO ji = 1, jpi
               p_taui(ji,jj) = zcoef * utau(ji,jj)
               p_tauj(ji,jj) = zcoef * vtau(ji,jj)
            END DO
         END DO
      CASE( 'B' )                          ! B-grid ice dynamics:  I-point (i.e. F-point lower-left corner)
!CDIR COLLAPSE
         DO jj = 2, jpj         ! stress from ocean U- and V-points to ice U,V point
            DO ji = 2, jpi   ! I-grid : no vector opt.
               p_taui(ji,jj) = 0.5 * ( utau(ji-1,jj  ) + utau(ji-1,jj-1) )
               p_taui(ji,jj) = 0.5 * ( utau(ji-1,jj  ) + utau(ji-1,jj-1) )
            END DO
         END DO
         CALL lbc_lnk( p_taui(:,:), 'I', -1. )   ;   CALL lbc_lnk( p_tauj(:,:), 'I', -1. )   ! I-point
      END SELECT

into

      SELECT CASE( cd_grid )
      CASE( 'C' )                          ! C-grid ice dynamics
      zcoef  = cai / cao                         ! Change from air-sea stress to air-ice stress
!CDIR COLLAPSE
         DO jj = 1 , jpj
            DO ji = 1, jpi
               p_taui(ji,jj) = zcoef * utau(ji,jj)
               p_tauj(ji,jj) = zcoef * vtau(ji,jj)
            END DO
         END DO
      CASE( 'B' )                          ! B-grid ice dynamics:  I-point (i.e. F-point lower-left corner)
      zcoef  = 0.5_wp * cai / cao                ! Change from air-sea stress to air-ice stress!CDIR COLLAPSE
!CDIR COLLAPSE
         DO jj = 2, jpj         ! stress from ocean U- and V-points to ice U,V point
            DO ji = 2, jpi   ! I-grid : no vector opt.
               p_taui(ji,jj) = zcoef2 * ( utau(ji-1,jj  ) + utau(ji-1,jj-1) )
               p_tauj(ji,jj) = zcoef2 * ( vtau(ji  ,jj-1) + vtau(ji-1,jj-1) )
            END DO
         END DO
         CALL lbc_lnk( p_taui(:,:), 'I', -1. )   ;   CALL lbc_lnk( p_tauj(:,:), 'I', -1. )   ! I-point
      END SELECT

[gm]

hups, Obviously in the modified code, zcoef2 stands for zcoef

Gurvan

[gm]

done in v3.3 beta see Changeset 2370

==>>> update v3.2 remains to be done

[smasson]

done for NEMO v3.2, see changeset:2388