pkg/shelfice/shelfice_v_drag.F

C $Header: /u/gcmpack/MITgcm/pkg/shelfice/shelfice_v_drag.F,v 1.5 2006/09/01 10:17:17 mlosch Exp $
C $Name:  $

#include "SHELFICE_OPTIONS.h"
#include "MOM_COMMON_OPTIONS.h"

CBOP
C !ROUTINE: SHELFICE_V_DRAG

C !INTERFACE: ==========================================================
      SUBROUTINE SHELFICE_V_DRAG(
     I        bi,bj,k,
     I        vFld, KE, KappaRV,
     O        vDragTerms,
     I        myThid)

C !DESCRIPTION:
C Calculates the drag due to friction and the no-slip condition at the
C bottom of the shelf-ice (in analogy to bottom drag)
C \begin{equation*}
C G^v_{drag} = - ( r_b + C_D |v| + \frac{2}{\Delta r_c} ) v
C \end{equation*}

C !USES: ===============================================================
      IMPLICIT NONE
#include "SIZE.h"
#include "EEPARAMS.h"
#include "PARAMS.h"
#include "GRID.h"
#include "SHELFICE.h"

C !INPUT PARAMETERS: ===================================================
C  bi,bj                :: tile indices
C  k                    :: vertical level
C  vFld                 :: meridional flow
C  KE                   :: Kinetic energy
C  KappaRV              :: vertical viscosity
C  myThid               :: thread number
      INTEGER bi,bj,k
      _RL vFld(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
      _RL KE(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
      _RL KappaRV(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
      INTEGER myThid

C !OUTPUT PARAMETERS: ==================================================
C  vDragTerms           :: drag term
      _RL vDragTerms(1-OLx:sNx+OLx,1-OLy:sNy+OLy)

#ifdef ALLOW_SHELFICE 
C !LOCAL VARIABLES : ====================================================
C  i,j                  :: loop indices
C  Kp1                  :: =k+1 for k<Nr, =Nr for k>=Nr
      INTEGER I,J,kUp,kUpC,kTop
      _RL viscFac
      _RL rdrckp1,maskUp
CEOP

C-  No-slip BCs impose a drag at top
      IF ( usingZCoords ) THEN
       kTop    = 1
       kUp     = max(k-1,kTop)
       kUpC    = k
      ELSE
       kTop    = Nr
       kUp     = min(k+1,kTop)
       kUpC    = kUp
      ENDIF     
      rdrckp1=recip_drC(kUpC)
CML      IF (k.EQ.kTop) rdrckp1=recip_drF(k)
      viscFac=0.
      IF (no_slip_shelfice) viscFac=1.
      DO j=1-Oly+1,sNy+Oly-1
       DO i=1-Olx,sNx+Olx-1
        maskUp=_maskS(i,j,kUp,bi,bj)
CML        IF (k.EQ.kTop) maskUp=0.
        vDragTerms(i,j)=
     &   -_recip_hFacS(i,j,k,bi,bj)*recip_drF(k)
     &   *( 
     &     - 2.*KappaRV(i,j,kUpC)*rdrckp1*viscFac
     &     + bottomDragLinear
     &    )*(1.-maskUp)*vFld(i,j)
        IF ( (KE(i,j)+KE(i,j-1)) .NE. 0. ) THEN
         vDragTerms(i,j)=vDragTerms(i,j)
     &    -_recip_hFacS(i,j,k,bi,bj)*recip_drF(k)
     &    *bottomDragQuadratic*sqrt(KE(i,j)+KE(i,j-1))
     &    *(1.-maskUp)*vFld(i,j)
        ENDIF
       ENDDO
      ENDDO

#ifdef ALLOW_DIAGNOSTICS
      IF (useDiagnostics) THEN
        CALL DIAGNOSTICS_FILL(vDragTerms,'VSHIDrag',k,1,2,bi,bj,myThid)
      ENDIF
#endif /* ALLOW_DIAGNOSTICS */
#endif /* ALLOW_SHELFICE */

      RETURN
      END
1	mlosch	1.6	C $Header: /u/gcmpack/MITgcm/pkg/shelfice/shelfice_v_drag.F,v 1.5 2006/09/01 10:17:17 mlosch Exp $
2	mlosch	1.1	C $Name: $
3
4			#include "SHELFICE_OPTIONS.h"
5			#include "MOM_COMMON_OPTIONS.h"
6
7			CBOP
8			C !ROUTINE: SHELFICE_V_DRAG
9
10			C !INTERFACE: ==========================================================
11			SUBROUTINE SHELFICE_V_DRAG(
12			I bi,bj,k,
13			I vFld, KE, KappaRV,
14			O vDragTerms,
15			I myThid)
16
17			C !DESCRIPTION:
18			C Calculates the drag due to friction and the no-slip condition at the
19			C bottom of the shelf-ice (in analogy to bottom drag)
20			C \begin{equation*}
21			C G^v_{drag} = - ( r_b + C_D \|v\| + \frac{2}{\Delta r_c} ) v
22			C \end{equation*}
23
24			C !USES: ===============================================================
25			IMPLICIT NONE
26			#include "SIZE.h"
27			#include "EEPARAMS.h"
28			#include "PARAMS.h"
29			#include "GRID.h"
30			#include "SHELFICE.h"
31
32			C !INPUT PARAMETERS: ===================================================
33			C bi,bj :: tile indices
34			C k :: vertical level
35			C vFld :: meridional flow
36			C KE :: Kinetic energy
37			C KappaRV :: vertical viscosity
38			C myThid :: thread number
39			INTEGER bi,bj,k
40			_RL vFld(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
41			_RL KE(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
42			_RL KappaRV(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
43			INTEGER myThid
44
45			C !OUTPUT PARAMETERS: ==================================================
46			C vDragTerms :: drag term
47			_RL vDragTerms(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
48
49	mlosch	1.3	#ifdef ALLOW_SHELFICE
50	mlosch	1.2	C !LOCAL VARIABLES : ====================================================
51	mlosch	1.1	C i,j :: loop indices
52			C Kp1 :: =k+1 for k<Nr, =Nr for k>=Nr
53			INTEGER I,J,kUp,kUpC,kTop
54	mlosch	1.4	_RL viscFac
55	mlosch	1.1	_RL rdrckp1,maskUp
56			CEOP
57
58	mlosch	1.3	C- No-slip BCs impose a drag at top
59	mlosch	1.1	IF ( usingZCoords ) THEN
60			kTop = 1
61	mlosch	1.4	kUp = max(k-1,kTop)
62			kUpC = k
63	mlosch	1.1	ELSE
64			kTop = Nr
65			kUp = min(k+1,kTop)
66			kUpC = kUp
67			ENDIF
68			rdrckp1=recip_drC(kUpC)
69	mlosch	1.4	CML IF (k.EQ.kTop) rdrckp1=recip_drF(k)
70	mlosch	1.1	viscFac=0.
71			IF (no_slip_shelfice) viscFac=1.
72			DO j=1-Oly+1,sNy+Oly-1
73			DO i=1-Olx,sNx+Olx-1
74			maskUp=_maskS(i,j,kUp,bi,bj)
75			CML IF (k.EQ.kTop) maskUp=0.
76			vDragTerms(i,j)=
77			& -_recip_hFacS(i,j,k,bi,bj)*recip_drF(k)
78			& *(
79	mlosch	1.5	& - 2.KappaRV(i,j,kUpC)rdrckp1*viscFac
80	mlosch	1.1	& + bottomDragLinear
81			& )(1.-maskUp)vFld(i,j)
82			IF ( (KE(i,j)+KE(i,j-1)) .NE. 0. ) THEN
83			vDragTerms(i,j)=vDragTerms(i,j)
84			& -_recip_hFacS(i,j,k,bi,bj)*recip_drF(k)
85			& bottomDragQuadraticsqrt(KE(i,j)+KE(i,j-1))
86			& (1.-maskUp)vFld(i,j)
87			ENDIF
88			ENDDO
89			ENDDO
90
91	mlosch	1.6	#ifdef ALLOW_DIAGNOSTICS
92			IF (useDiagnostics) THEN
93			CALL DIAGNOSTICS_FILL(vDragTerms,'VSHIDrag',k,1,2,bi,bj,myThid)
94			ENDIF
95			#endif /* ALLOW_DIAGNOSTICS */
96	mlosch	1.3	#endif /* ALLOW_SHELFICE */
97	mlosch	1.1
98			RETURN
99			END