/[MITgcm]/MITgcm/pkg/seaice/seaice_calc_strainrates.F
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Contents of /MITgcm/pkg/seaice/seaice_calc_strainrates.F

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Revision 1.13 - (show annotations) (download)
Wed Jun 3 08:48:07 2009 UTC (15 years ago) by mlosch
Branch: MAIN
CVS Tags: checkpoint61p, checkpoint61q
Changes since 1.12: +1 -2 lines
fix comments

1 C $Header: /u/gcmpack/MITgcm/pkg/seaice/seaice_calc_strainrates.F,v 1.12 2009/05/29 10:18:02 mlosch Exp $
2 C $Name: $
3
4 #include "SEAICE_OPTIONS.h"
5
6 CStartOfInterface
7 SUBROUTINE SEAICE_CALC_STRAINRATES(
8 I uFld, vFld,
9 O e11Loc, e22Loc, e12Loc,
10 I kSize, iStep, myTime, myIter, myThid )
11 C /==========================================================\
12 C | SUBROUTINE SEAICE_CALC_STRAINRATES |
13 C | o compute strain rates from ice velocities |
14 C |==========================================================|
15 C | written by Martin Losch, Apr 2007 |
16 C \==========================================================/
17 IMPLICIT NONE
18
19 C === Global variables ===
20 #include "SIZE.h"
21 #include "EEPARAMS.h"
22 #include "PARAMS.h"
23 #include "GRID.h"
24 #include "SEAICE_PARAMS.h"
25 #include "SEAICE.h"
26
27 #ifdef ALLOW_AUTODIFF_TAMC
28 # include "tamc.h"
29 #endif
30
31 C === Routine arguments ===
32 C iStep :: Sub-time-step number
33 C myTime :: Simulation time
34 C myIter :: Simulation timestep number
35 C myThid :: My Thread Id. number
36 C kSize :: length of 3rd dimension of velocity variables
37 INTEGER iStep
38 _RL myTime
39 INTEGER myIter
40 INTEGER myThid
41 INTEGER kSize
42 C ice velocities
43 _RL uFld(1-Olx:sNx+Olx,1-Oly:sNy+Oly,kSize,nSx,nSy)
44 _RL vFld(1-Olx:sNx+Olx,1-Oly:sNy+Oly,kSize,nSx,nSy)
45 C strain rate tensor
46 _RL e11Loc (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy)
47 _RL e22Loc (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy)
48 _RL e12Loc (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy)
49 CEndOfInterface
50
51 #ifdef SEAICE_CGRID
52 #ifdef SEAICE_ALLOW_DYNAMICS
53 C === Local variables ===
54 C i,j,bi,bj - Loop counters
55 INTEGER i, j, bi, bj
56 C hFacU, hFacV - determine the no-slip boundary condition
57 INTEGER k
58 _RS hFacU, hFacV, noSlipFac
59
60 k = 1
61 noSlipFac = 0. _d 0
62 IF ( SEAICE_no_slip ) noSlipFac = 1. _d 0
63 C
64 #ifndef SEAICE_OLD_AND_BAD_DISCRETIZATION
65 DO bj=myByLo(myThid),myByHi(myThid)
66 DO bi=myBxLo(myThid),myBxHi(myThid)
67 DO j=1-Oly,sNy+Oly-1
68 DO i=1-Olx,sNx+Olx-1
69 C evaluate strain rates
70 e11Loc(I,J,bi,bj) = _recip_dxF(I,J,bi,bj) *
71 & (uFld(I+1,J,1,bi,bj)-uFld(I,J,1,bi,bj))
72 & +HALF*
73 & (vFld(I,J,1,bi,bj)+vFld(I,J+1,1,bi,bj))
74 & * k2AtC(I,J,bi,bj)
75 e22Loc(I,J,bi,bj) = _recip_dyF(I,J,bi,bj) *
76 & (vFld(I,J+1,1,bi,bj)-vFld(I,J,1,bi,bj))
77 & +HALF*
78 & (uFld(I,J,1,bi,bj)+uFld(I+1,J,1,bi,bj))
79 & * k1AtC(I,J,bi,bj)
80 ENDDO
81 ENDDO
82 DO j=1-Oly+1,sNy+Oly
83 DO i=1-Olx+1,sNx+Olx
84 hFacU = _maskW(i,j,k,bi,bj) - _maskW(i,j-1,k,bi,bj)
85 hFacV = _maskS(i,j,k,bi,bj) - _maskS(i-1,j,k,bi,bj)
86 e12Loc(I,J,bi,bj) = HALF*(
87 & ( uFld(I,J,1,bi,bj) - uFld(I ,J-1,1,bi,bj) )
88 & * _recip_dyU(I,J,bi,bj)
89 & + ( vFld(I,J,1,bi,bj) - vFld(I-1,J ,1,bi,bj) )
90 & * _recip_dxV(I,J,bi,bj)
91 & - k1AtZ(I,J,bi,bj)
92 & * 0.5 _d 0 * (vFld(I,J,1,bi,bj)+vFld(I-1,J ,1,bi,bj))
93 & - k2AtZ(I,J,bi,bj)
94 & * 0.5 _d 0 * (uFld(I,J,1,bi,bj)+uFld(I ,J-1,1,bi,bj))
95 & )
96 & *maskC(I ,J ,k,bi,bj)*maskC(I-1,J ,k,bi,bj)
97 & *maskC(I ,J-1,k,bi,bj)*maskC(I-1,J-1,k,bi,bj)
98 & + 2.0 _d 0 * noSlipFac * (
99 & ( uFld(I,J,1,bi,bj) + uFld(I ,J-1,1,bi,bj) )
100 & * _recip_dyU(I,J,bi,bj) * hFacU
101 & + ( vFld(I,J,1,bi,bj) + vFld(I-1,J ,1,bi,bj) )
102 & * _recip_dxV(I,J,bi,bj) * hFacV
103 & )
104 C no slip at the boundary implies u(j)+u(j-1)=0 and v(i)+v(i-1)=0
105 C accross the boundary; this is already accomplished by masking so
106 C that the following lines are not necessary
107 c$$$ & - hFacV * k1AtZ(I,J,bi,bj)
108 c$$$ & * 0.5 _d 0 * (vFld(I,J,1,bi,bj)+vFld(I-1,J ,1,bi,bj))
109 c$$$ & - hFacU * k2AtZ(I,J,bi,bj)
110 c$$$ & * 0.5 _d 0 * (uFld(I,J,1,bi,bj)+uFld(I ,J-1,1,bi,bj))
111 ENDDO
112 ENDDO
113
114 c$$$ ENDIF
115 ENDDO
116 ENDDO
117 #else
118 C this the old and incomplete discretization, here I also erroneously
119 C used finite-volumes to discretize the strain rates
120 DO bj=myByLo(myThid),myByHi(myThid)
121 DO bi=myBxLo(myThid),myBxHi(myThid)
122 DO j=1-Oly,sNy+Oly-1
123 DO i=1-Olx,sNx+Olx-1
124 C evaluate strain rates
125 e11Loc(I,J,bi,bj) = _recip_dxF(I,J,bi,bj) *
126 & (uFld(I+1,J,1,bi,bj)-uFld(I,J,1,bi,bj))
127 & -HALF*
128 & (vFld(I,J,1,bi,bj)+vFld(I,J+1,1,bi,bj))
129 & * _tanPhiAtU(I,J,bi,bj)*recip_rSphere
130 e22Loc(I,J,bi,bj) = _recip_dyF(I,J,bi,bj) *
131 & (vFld(I,J+1,1,bi,bj)-vFld(I,J,1,bi,bj))
132 C one metric term is missing
133 ENDDO
134 ENDDO
135 DO j=1-Oly+1,sNy+Oly
136 DO i=1-Olx+1,sNx+Olx
137 e12Loc(I,J,bi,bj) = HALF*(
138 & (uFld(I ,J ,1,bi,bj) * _dxC(I ,J ,bi,bj)
139 & -uFld(I ,J-1,1,bi,bj) * _dxC(I ,J-1,bi,bj)
140 & +vFld(I ,J ,1,bi,bj) * _dyC(I ,J ,bi,bj)
141 & -vFld(I-1,J ,1,bi,bj) * _dyC(I-1,J ,bi,bj))
142 & * recip_rAz(I,J,bi,bj)
143 & +
144 & 0.25 _d 0 * (uFld(I,J,1,bi,bj)+uFld(I ,J-1,1,bi,bj))
145 & * ( _tanPhiAtU(I,J,bi,bj) + _tanPhiAtU(I,J-1,bi,bj) )
146 & *recip_rSphere
147 & )
148 & *maskC(I ,J ,k,bi,bj)*maskC(I-1,J ,k,bi,bj)
149 & *maskC(I ,J-1,k,bi,bj)*maskC(I-1,J-1,k,bi,bj)
150 C one metric term is missing
151 ENDDO
152 ENDDO
153 IF ( SEAICE_no_slip ) THEN
154 C no slip boundary conditions apply only to e12Loc
155 DO j=1-Oly+1,sNy+Oly
156 DO i=1-Olx+1,sNx+Olx
157 hFacU = _maskW(i,j,k,bi,bj) - _maskW(i,j-1,k,bi,bj)
158 hFacV = _maskS(i,j,k,bi,bj) - _maskS(i-1,j,k,bi,bj)
159
160 e12Loc(I,J,bi,bj) = e12Loc(I,J,bi,bj)
161 & + recip_rAz(i,j,bi,bj) * 2. _d 0 *
162 & ( hFacU * ( _dxC(i,j-1,bi,bj)*uFld(i,j ,1,bi,bj)
163 & + _dxC(i,j, bi,bj)*uFld(i,j-1,1,bi,bj) )
164 & + hFacV * ( _dyC(i-1,j,bi,bj)*vFld(i ,j,1,bi,bj)
165 & + _dyC(i, j,bi,bj)*vFld(i-1,j,1,bi,bj) ) )
166 & - hFacU
167 & * 0.25 _d 0 * (uFld(I,J,1,bi,bj)+uFld(I ,J-1,1,bi,bj))
168 & * ( _tanPhiAtU(I,J,bi,bj) + _tanPhiAtU(I,J-1,bi,bj) )
169 & *recip_rSphere
170 C one metric term is missing
171 ENDDO
172 ENDDO
173
174 ENDIF
175 ENDDO
176 ENDDO
177 #endif /* SEAICE_OLD_AND_BAD_DISCRETIZATION */
178 #endif /* SEAICE_ALLOW_DYNAMICS */
179 #endif /* SEAICE_CGRID */
180 RETURN
181 END

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