1 |
C $Header: /u/gcmpack/MITgcm/model/src/timestep.F,v 1.37 2005/04/15 14:17:31 jmc Exp $ |
2 |
C $Name: $ |
3 |
|
4 |
#include "PACKAGES_CONFIG.h" |
5 |
#include "CPP_OPTIONS.h" |
6 |
|
7 |
CBOP |
8 |
C !ROUTINE: TIMESTEP |
9 |
C !INTERFACE: |
10 |
SUBROUTINE TIMESTEP( bi, bj, iMin, iMax, jMin, jMax, k, |
11 |
I dPhiHydX,dPhiHydY, phiSurfX, phiSurfY, |
12 |
I guDissip, gvDissip, |
13 |
I myTime, myIter, myThid ) |
14 |
C !DESCRIPTION: \bv |
15 |
C *==========================================================* |
16 |
C | S/R TIMESTEP |
17 |
C | o Step model fields forward in time |
18 |
C *==========================================================* |
19 |
C \ev |
20 |
|
21 |
C !USES: |
22 |
IMPLICIT NONE |
23 |
C == Global variables == |
24 |
#include "SIZE.h" |
25 |
#include "DYNVARS.h" |
26 |
#include "EEPARAMS.h" |
27 |
#include "PARAMS.h" |
28 |
#include "GRID.h" |
29 |
#include "SURFACE.h" |
30 |
|
31 |
C !INPUT/OUTPUT PARAMETERS: |
32 |
C == Routine Arguments == |
33 |
C dPhiHydX,Y :: Gradient (X & Y directions) of Hydrostatic Potential |
34 |
C phiSurfX :: gradient of Surface potential (Pressure/rho, ocean) |
35 |
C phiSurfY :: or geopotential (atmos) in X and Y direction |
36 |
C guDissip :: dissipation tendency (all explicit terms), u component |
37 |
C gvDissip :: dissipation tendency (all explicit terms), v component |
38 |
|
39 |
INTEGER bi,bj,iMin,iMax,jMin,jMax |
40 |
INTEGER k |
41 |
_RL dPhiHydX(1-Olx:sNx+Olx,1-Oly:sNy+Oly) |
42 |
_RL dPhiHydY(1-Olx:sNx+Olx,1-Oly:sNy+Oly) |
43 |
_RL phiSurfX(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
44 |
_RL phiSurfY(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
45 |
_RL guDissip(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
46 |
_RL gvDissip(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
47 |
_RL myTime |
48 |
INTEGER myIter, myThid |
49 |
|
50 |
C !LOCAL VARIABLES: |
51 |
C == Local variables == |
52 |
LOGICAL momForcing_In_AB |
53 |
LOGICAL momDissip_In_AB |
54 |
INTEGER i,j |
55 |
_RL ab15,ab05 |
56 |
_RL phxFac,phyFac, psFac |
57 |
_RL gUtmp(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
58 |
_RL gVtmp(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
59 |
#ifdef ALLOW_CD_CODE |
60 |
_RL guCor(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
61 |
_RL gvCor(1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
62 |
#endif |
63 |
CEOP |
64 |
|
65 |
C Adams-Bashforth timestepping weights |
66 |
IF (myIter .EQ. 0) THEN |
67 |
ab15=1.0 |
68 |
ab05=0.0 |
69 |
ELSE |
70 |
ab15=1.5+abeps |
71 |
ab05=-0.5-abeps |
72 |
ENDIF |
73 |
|
74 |
C-- explicit part of the surface potential gradient is added in this S/R |
75 |
psFac = pfFacMom*(1. _d 0 - implicSurfPress) |
76 |
|
77 |
C-- factors for gradient (X & Y directions) of Hydrostatic Potential |
78 |
phxFac = pfFacMom |
79 |
phyFac = pfFacMom |
80 |
|
81 |
C-- including or excluding momentum forcing from Adams-Bashforth: |
82 |
momForcing_In_AB = forcing_In_AB |
83 |
momForcing_In_AB = .TRUE. |
84 |
momDissip_In_AB = .TRUE. |
85 |
|
86 |
C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----| |
87 |
|
88 |
C- Initialize local arrays (not really necessary but safer) |
89 |
DO j=1-Oly,sNy+Oly |
90 |
DO i=1-Olx,sNx+Olx |
91 |
gUtmp(i,j) = 0. _d 0 |
92 |
gVtmp(i,j) = 0. _d 0 |
93 |
#ifdef ALLOW_CD_CODE |
94 |
guCor(i,j) = 0. _d 0 |
95 |
gvCor(i,j) = 0. _d 0 |
96 |
#endif |
97 |
ENDDO |
98 |
ENDDO |
99 |
|
100 |
IF ( .NOT.staggerTimeStep ) THEN |
101 |
C-- Synchronous time step: add grad Phi_Hyp to gU,gV before doing Adams-Bashforth |
102 |
DO j=jMin,jMax |
103 |
DO i=iMin,iMax |
104 |
gU(i,j,k,bi,bj) = gU(i,j,k,bi,bj) - phxFac*dPhiHydX(i,j) |
105 |
gV(i,j,k,bi,bj) = gV(i,j,k,bi,bj) - phyFac*dPhiHydY(i,j) |
106 |
ENDDO |
107 |
ENDDO |
108 |
phxFac = 0. |
109 |
phyFac = 0. |
110 |
c ELSE |
111 |
C-- Stagger time step: grad Phi_Hyp will be added later |
112 |
ENDIF |
113 |
|
114 |
C-- Dissipation term inside the Adams-Bashforth: |
115 |
IF ( momViscosity .AND. momDissip_In_AB) THEN |
116 |
DO j=jMin,jMax |
117 |
DO i=iMin,iMax |
118 |
gU(i,j,k,bi,bj) = gU(i,j,k,bi,bj) + guDissip(i,j) |
119 |
gV(i,j,k,bi,bj) = gV(i,j,k,bi,bj) + gvDissip(i,j) |
120 |
ENDDO |
121 |
ENDDO |
122 |
ENDIF |
123 |
|
124 |
C-- Forcing term inside the Adams-Bashforth: |
125 |
IF (momForcing .AND. momForcing_In_AB) THEN |
126 |
CALL EXTERNAL_FORCING_U( |
127 |
I iMin,iMax,jMin,jMax,bi,bj,k, |
128 |
I myTime,myThid) |
129 |
CALL EXTERNAL_FORCING_V( |
130 |
I iMin,iMax,jMin,jMax,bi,bj,k, |
131 |
I myTime,myThid) |
132 |
ENDIF |
133 |
|
134 |
IF (useCDscheme) THEN |
135 |
C- for CD-scheme, store gU,Vtmp = gU,V^n + forcing |
136 |
DO j=jMin,jMax |
137 |
DO i=iMin,iMax |
138 |
gUtmp(i,j) = gU(i,j,k,bi,bj) |
139 |
gVtmp(i,j) = gV(i,j,k,bi,bj) |
140 |
ENDDO |
141 |
ENDDO |
142 |
ENDIF |
143 |
|
144 |
C- Compute effective gU,gV_[n+1/2] terms (including Adams-Bashforth weights) |
145 |
C and save gU,gV_[n] into guNm1,gvNm1 for the next time step. |
146 |
#ifdef ALLOW_ADAMSBASHFORTH_3 |
147 |
CALL ADAMS_BASHFORTH3( |
148 |
I bi, bj, k, |
149 |
U gU, guNm, |
150 |
I myIter, myThid ) |
151 |
CALL ADAMS_BASHFORTH3( |
152 |
I bi, bj, k, |
153 |
U gV, gvNm, |
154 |
I myIter, myThid ) |
155 |
#else /* ALLOW_ADAMSBASHFORTH_3 */ |
156 |
CALL ADAMS_BASHFORTH2( |
157 |
I bi, bj, k, |
158 |
U gU, guNm1, |
159 |
I myIter, myThid ) |
160 |
CALL ADAMS_BASHFORTH2( |
161 |
I bi, bj, k, |
162 |
U gV, gvNm1, |
163 |
I myIter, myThid ) |
164 |
#endif /* ALLOW_ADAMSBASHFORTH_3 */ |
165 |
|
166 |
C-- Forcing term outside the Adams-Bashforth: |
167 |
C (not recommanded with CD-scheme ON) |
168 |
IF (momForcing .AND. .NOT.momForcing_In_AB) THEN |
169 |
IF (useCDscheme) THEN |
170 |
DO j=jMin,jMax |
171 |
DO i=iMin,iMax |
172 |
gUtmp(i,j) = gUtmp(i,j) - gU(i,j,k,bi,bj) |
173 |
gVtmp(i,j) = gVtmp(i,j) - gV(i,j,k,bi,bj) |
174 |
ENDDO |
175 |
ENDDO |
176 |
ENDIF |
177 |
CALL EXTERNAL_FORCING_U( |
178 |
I iMin,iMax,jMin,jMax,bi,bj,k, |
179 |
I myTime,myThid) |
180 |
CALL EXTERNAL_FORCING_V( |
181 |
I iMin,iMax,jMin,jMax,bi,bj,k, |
182 |
I myTime,myThid) |
183 |
|
184 |
C- for CD-scheme, compute gU,Vtmp = gU,V^n + forcing |
185 |
IF (useCDscheme) THEN |
186 |
DO j=jMin,jMax |
187 |
DO i=iMin,iMax |
188 |
gUtmp(i,j) = gUtmp(i,j) + gU(i,j,k,bi,bj) |
189 |
gVtmp(i,j) = gVtmp(i,j) + gV(i,j,k,bi,bj) |
190 |
ENDDO |
191 |
ENDDO |
192 |
ENDIF |
193 |
ENDIF |
194 |
|
195 |
#ifdef ALLOW_CD_CODE |
196 |
IF (useCDscheme) THEN |
197 |
C- Step forward D-grid velocity using C-grid gU,Vtmp = gU,V^n + forcing |
198 |
C and return coriolis terms on C-grid (guCor,gvCor) |
199 |
CALL CD_CODE_SCHEME( |
200 |
I bi,bj,k, dPhiHydX,dPhiHydY, gUtmp,gVtmp, |
201 |
O guCor,gvCor, |
202 |
I myTime, myIter, myThid) |
203 |
DO j=jMin,jMax |
204 |
DO i=iMin,iMax |
205 |
gUtmp(i,j) = gU(i,j,k,bi,bj) |
206 |
& + guCor(i,j) |
207 |
gVtmp(i,j) = gV(i,j,k,bi,bj) |
208 |
& + gvCor(i,j) |
209 |
ENDDO |
210 |
ENDDO |
211 |
ELSE |
212 |
#endif /* ALLOW_CD_CODE */ |
213 |
DO j=jMin,jMax |
214 |
DO i=iMin,iMax |
215 |
gUtmp(i,j) = gU(i,j,k,bi,bj) |
216 |
gVtmp(i,j) = gV(i,j,k,bi,bj) |
217 |
ENDDO |
218 |
ENDDO |
219 |
#ifdef ALLOW_CD_CODE |
220 |
ENDIF |
221 |
#endif |
222 |
|
223 |
#ifdef NONLIN_FRSURF |
224 |
IF (.NOT. vectorInvariantMomentum |
225 |
& .AND. nonlinFreeSurf.GT.1) THEN |
226 |
IF (select_rStar.GT.0) THEN |
227 |
DO j=jMin,jMax |
228 |
DO i=iMin,iMax |
229 |
gUtmp(i,j) = gUtmp(i,j)/rStarExpW(i,j,bi,bj) |
230 |
gVtmp(i,j) = gVtmp(i,j)/rStarExpS(i,j,bi,bj) |
231 |
ENDDO |
232 |
ENDDO |
233 |
ELSE |
234 |
DO j=jMin,jMax |
235 |
DO i=iMin,iMax |
236 |
IF ( k.EQ.ksurfW(i,j,bi,bj) ) THEN |
237 |
gUtmp(i,j) = gUtmp(i,j) |
238 |
& *hFacW(i,j,k,bi,bj)/hFac_surfW(i,j,bi,bj) |
239 |
ENDIF |
240 |
IF ( k.EQ.ksurfS(i,j,bi,bj) ) THEN |
241 |
gVtmp(i,j) = gVtmp(i,j) |
242 |
& *hFacS(i,j,k,bi,bj)/hFac_surfS(i,j,bi,bj) |
243 |
ENDIF |
244 |
ENDDO |
245 |
ENDDO |
246 |
ENDIF |
247 |
ENDIF |
248 |
#endif /* NONLIN_FRSURF */ |
249 |
|
250 |
C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----| |
251 |
|
252 |
C-- Dissipation term outside the Adams-Bashforth: |
253 |
IF ( momViscosity .AND. .NOT.momDissip_In_AB ) THEN |
254 |
DO j=jMin,jMax |
255 |
DO i=iMin,iMax |
256 |
gUtmp(i,j) = gUtmp(i,j) + guDissip(i,j) |
257 |
gVtmp(i,j) = gVtmp(i,j) + gvDissip(i,j) |
258 |
ENDDO |
259 |
ENDDO |
260 |
ENDIF |
261 |
|
262 |
C Step forward zonal velocity (store in Gu) |
263 |
DO j=jMin,jMax |
264 |
DO i=iMin,iMax |
265 |
gU(i,j,k,bi,bj) = uVel(i,j,k,bi,bj) |
266 |
& +deltaTmom*( |
267 |
& gUtmp(i,j) |
268 |
& - psFac*phiSurfX(i,j) |
269 |
& - phxFac*dPhiHydX(i,j) |
270 |
& )*_maskW(i,j,k,bi,bj) |
271 |
ENDDO |
272 |
ENDDO |
273 |
|
274 |
C Step forward meridional velocity (store in Gv) |
275 |
DO j=jMin,jMax |
276 |
DO i=iMin,iMax |
277 |
gV(i,j,k,bi,bj) = vVel(i,j,k,bi,bj) |
278 |
& +deltaTmom*( |
279 |
& gVtmp(i,j) |
280 |
& - psFac*phiSurfY(i,j) |
281 |
& - phyFac*dPhiHydY(i,j) |
282 |
& )*_maskS(i,j,k,bi,bj) |
283 |
ENDDO |
284 |
ENDDO |
285 |
|
286 |
RETURN |
287 |
END |