Changeset 13002 for NEMO/branches/UKMO/NEMO_4.0.1_GM_rossby_radius_cutoff/src/OCE/LDF/ldftra.F90

Timestamp:

2020-06-02T09:03:47+02:00 (3 years ago)

Author:

davestorkey

Message:

UKMO/NEMO_4.0.1_GM_rossby_radius_cutoff : Add two versions of a ramp in addition to the abrupt cutoff on the RR/GS ratio.

File:

• NEMO/branches/UKMO/NEMO_4.0.1_GM_rossby_radius_cutoff/src/OCE/LDF/ldftra.F90 (modified) (5 diffs)

NEMO/branches/UKMO/NEMO_4.0.1_GM_rossby_radius_cutoff/src/OCE/LDF/ldftra.F90

@@ -72 +72 @@
    REAL(wp), PUBLIC ::      rn_Ue               !: lateral diffusive velocity  [m/s]
    REAL(wp), PUBLIC ::      rn_Le               !: lateral diffusive length    [m]
+   INTEGER,  PUBLIC ::   nn_ldfeiv_shape     !: shape of bounding coefficient (Treguier et al formulation only)
    
    !                                  ! Flag to control the type of lateral diffusive operator
@@ -503 +504 @@
       !!
       NAMELIST/namtra_eiv/ ln_ldfeiv   , ln_ldfeiv_dia,   &   ! eddy induced velocity (eiv)
-         &                 nn_aei_ijk_t, rn_Ue, rn_Le         ! eiv  coefficient
+         &                 nn_aei_ijk_t, rn_Ue, rn_Le,    &   ! eiv  coefficient
+         &                 nn_ldfeiv_shape
       !!----------------------------------------------------------------------
       !
@@ -597 +599 @@
             IF(lwp) WRITE(numout,*) '                                       = F( growth rate of baroclinic instability )'
             IF(lwp) WRITE(numout,*) '           maximum allowed value: aei0 = ', aei0, ' m2/s'
+            IF(lwp) WRITE(numout,*) '           shape of bounding coefficient : ',nn_ldfeiv_shape
             !
             l_ldfeiv_time = .TRUE.     ! will be calculated by call to ldf_tra routine in step.F90
@@ -654 +657 @@
       !
       INTEGER  ::   ji, jj, jk    ! dummy loop indices
-      REAL(wp) ::   zfw, ze3w, zn2, z1_f20, zaht, zaht_min, zzaei    ! local scalars
-      REAL(wp), DIMENSION(jpi,jpj) ::   zn, zah, zhw, zRo, zRo_lim, zaeiw   ! 2D workspace
+      REAL(wp) ::   zfw, ze3w, zn2, z1_f20, zaht, zaht_min, zzaei, z2_3    ! local scalars
+      REAL(wp), DIMENSION(jpi,jpj) ::   zn, zah, zhw, zRo, zRo_lim, zaeiw, zratio   ! 2D workspace
       !!----------------------------------------------------------------------
       !
@@ -713 +716 @@
          END DO
       END DO
+      IF( iom_use('N_2d') ) CALL iom_put('N_2d',zn(:,:)/ht_0(:,:))
       CALL iom_put('RossRad',zRo)
       !                                         !==  Bound on eiv coeff.  ==!
       z1_f20 = 1._wp / (  2._wp * omega * sin( rad * 20._wp )  )
+      z2_3 = 2._wp/3._wp
       DO jj = 2, jpjm1
          DO ji = fs_2, fs_jpim1   ! vector opt.
             zzaei = MIN( 1._wp, ABS( ff_t(ji,jj) * z1_f20 ) ) * zaeiw(ji,jj)     ! tropical decrease
+            zaeiw(ji,jj) = MIN( zzaei, paei0 )
+         END DO
+      END DO
+
+      !! temporary fudge for diagnostic purposes:
+      !! zaeiw(:,:) = paei0 
+
+      SELECT CASE(nn_ldfeiv_shape)
+         CASE(1) !! Abrupt cut-off on Rossby radius:
 ! JD : modifications here to introduce scaling by local rossby radius of deformation vs local grid scale
 ! arbitrary decision that GM is de-activated if local rossy radius larger than 2 times local grid scale
 ! based on Hallberg (2013)
-            IF ( l_Ro_cutoff .AND. zRo(ji,jj) >= ( 2._wp * MIN( e1t(ji,jj), e2t(ji,jj) ) ) ) THEN
+            DO jj = 2, jpjm1
+               DO ji = fs_2, fs_jpim1   ! vector opt.
+                  IF ( l_Ro_cutoff .AND. zRo(ji,jj) >= ( 2._wp * MIN( e1t(ji,jj), e2t(ji,jj) ) ) ) THEN
 ! TODO : use a version of zRo that integrates over a few time steps ?
-                zaeiw(ji,jj) = 0._wp
-            ELSE
-                zaeiw(ji,jj) = MIN( zzaei, paei0 )
-            ENDIF
-         END DO
-      END DO
+                      zaeiw(ji,jj) = 0._wp
+                  ELSE
+                      zaeiw(ji,jj) = MIN( zaeiw(ji,jj), paei0 )
+                  ENDIF
+               END DO
+            END DO
+
+         CASE(2) !! Rossby radius ramp type 1:
+            DO jj = 2, jpjm1
+               DO ji = fs_2, fs_jpim1   ! vector opt.
+                  zratio(ji,jj) = zRo(ji,jj)/MIN(e1t(ji,jj),e2t(ji,jj))
+                  zaeiw(ji,jj) = MIN( zaeiw(ji,jj), MAX( 0._wp, MIN( 1._wp, z2_3*(2._wp - zratio(ji,jj)) ) ) * paei0 )
+               END DO
+            END DO
+            CALL iom_put('RR_GS',zratio)
+
+         CASE(3) !! Rossby radius ramp type 2:
+            DO jj = 2, jpjm1
+               DO ji = fs_2, fs_jpim1   ! vector opt.
+                  zratio(ji,jj) = MIN(e1t(ji,jj),e2t(ji,jj))/zRo(ji,jj)
+                  zaeiw(ji,jj) = MIN( zaeiw(ji,jj), MAX( 0._wp, MIN( 1._wp, z2_3*( zratio(ji,jj) - 0.5_wp ) ) ) * paei0 )
+               END DO
+            END DO
+            CALL iom_put('GS_RR',zratio)
+
+      END SELECT
+
       CALL lbc_lnk( 'ldftra', zaeiw(:,:), 'W', 1. )       ! lateral boundary condition
       !