1 |
C $Header: /u/gcmpack/MITgcm/pkg/seaice/seaice_ocean_stress.F,v 1.8 2006/03/20 21:36:11 mlosch Exp $ |
2 |
C $Name: $ |
3 |
|
4 |
#include "SEAICE_OPTIONS.h" |
5 |
|
6 |
CStartOfInterface |
7 |
SUBROUTINE SEAICE_OCEAN_STRESS( |
8 |
I myTime, myIter, myThid ) |
9 |
C /==========================================================\ |
10 |
C | SUBROUTINE SEAICE_OCEAN_STRESS | |
11 |
C | o Calculate ocean surface stresses | |
12 |
C | - C-grid version | |
13 |
C |==========================================================| |
14 |
C \==========================================================/ |
15 |
IMPLICIT NONE |
16 |
|
17 |
C === Global variables === |
18 |
#include "SIZE.h" |
19 |
#include "EEPARAMS.h" |
20 |
#include "PARAMS.h" |
21 |
#include "GRID.h" |
22 |
#include "FFIELDS.h" |
23 |
#include "SEAICE.h" |
24 |
#include "SEAICE_PARAMS.h" |
25 |
#include "SEAICE_FFIELDS.h" |
26 |
|
27 |
C === Routine arguments === |
28 |
C myTime - Simulation time |
29 |
C myIter - Simulation timestep number |
30 |
C myThid - Thread no. that called this routine. |
31 |
_RL myTime |
32 |
INTEGER myIter |
33 |
INTEGER myThid |
34 |
CEndOfInterface |
35 |
|
36 |
#ifdef SEAICE_CGRID |
37 |
C === Local variables === |
38 |
C i,j,bi,bj - Loop counters |
39 |
|
40 |
INTEGER i, j, bi, bj |
41 |
_RL SINWAT, COSWAT, SINWIN, COSWIN |
42 |
_RL fuIce, fvIce, FX, FY |
43 |
_RL areaW, areaS |
44 |
|
45 |
_RL press (1-Olx:sNx+Olx,1-Oly:sNy+Oly,nSx,nSy) |
46 |
_RL etaPlusZeta (1-Olx:sNx+Olx,1-Oly:sNy+Oly) |
47 |
_RL zetaMinusEta(1-Olx:sNx+Olx,1-Oly:sNy+Oly) |
48 |
_RL etaMeanZ (1-Olx:sNx+Olx,1-Oly:sNy+Oly) |
49 |
_RL etaMeanU (1-Olx:sNx+Olx,1-Oly:sNy+Oly) |
50 |
_RL etaMeanV (1-Olx:sNx+Olx,1-Oly:sNy+Oly) |
51 |
_RL dVdx (1-Olx:sNx+Olx,1-Oly:sNy+Oly) |
52 |
_RL dVdy (1-Olx:sNx+Olx,1-Oly:sNy+Oly) |
53 |
_RL dUdx (1-Olx:sNx+Olx,1-Oly:sNy+Oly) |
54 |
_RL dUdy (1-Olx:sNx+Olx,1-Oly:sNy+Oly) |
55 |
|
56 |
c introduce turning angle (default is zero) |
57 |
SINWAT=SIN(SEAICE_waterTurnAngle*deg2rad) |
58 |
COSWAT=COS(SEAICE_waterTurnAngle*deg2rad) |
59 |
SINWIN=SIN(SEAICE_airTurnAngle*deg2rad) |
60 |
COSWIN=COS(SEAICE_airTurnAngle*deg2rad) |
61 |
|
62 |
C-- Update overlap regions |
63 |
CALL EXCH_UV_XY_RL(WINDX, WINDY, .TRUE., myThid) |
64 |
|
65 |
#ifndef SEAICE_EXTERNAL_FLUXES |
66 |
C-- Interpolate wind stress (N/m^2) from C-points of C-grid |
67 |
C to U and V points of C-grid for forcing the ocean model. |
68 |
DO bj=myByLo(myThid),myByHi(myThid) |
69 |
DO bi=myBxLo(myThid),myBxHi(myThid) |
70 |
DO j=1,sNy |
71 |
DO i=1,sNx |
72 |
fu(I,J,bi,bj)=0.5*(WINDX(I,J,bi,bj) + WINDX(I-1,J,bi,bj)) |
73 |
fv(I,J,bi,bj)=0.5*(WINDY(I,J,bi,bj) + WINDY(I,J-1,bi,bj)) |
74 |
ENDDO |
75 |
ENDDO |
76 |
ENDDO |
77 |
ENDDO |
78 |
#endif /* ifndef SEAICE_EXTERNAL_FLUXES */ |
79 |
|
80 |
IF ( useHB87StressCoupling ) THEN |
81 |
C |
82 |
C use an intergral over ice and ocean surface layer to define |
83 |
C surface stresses on ocean following Hibler and Bryan (1987, JPO) |
84 |
C |
85 |
C recompute viscosities from updated ice velocities |
86 |
CALL SEAICE_CALC_VISCOSITIES( |
87 |
I uIce(1-Olx,1-Oly,1,1,1), vIce(1-Olx,1-Oly,1,1,1), |
88 |
I zMin, zMax, hEffM, press0, |
89 |
O eta, zeta, press, |
90 |
#ifdef SEAICE_ALLOW_EVP |
91 |
O seaice_div, seaice_tension, seaice_shear, |
92 |
#endif /* SEAICE_ALLOW_EVP */ |
93 |
I myThid ) |
94 |
C re-compute internal stresses with updated ice velocities |
95 |
DO bj=myByLo(myThid),myByHi(myThid) |
96 |
DO bi=myBxLo(myThid),myBxHi(myThid) |
97 |
DO j=1-Oly+1,sNy+Oly-1 |
98 |
DO i=1-Olx+1,sNx+Olx-1 |
99 |
etaPlusZeta (I,J) = eta(I,J,bi,bj) + zeta(I,J,bi,bj) |
100 |
zetaMinusEta(I,J) = zeta(I,J,bi,bj) - eta(I,J,bi,bj) |
101 |
etaMeanU (I,J) = |
102 |
& HALF*(ETA (I,J,bi,bj) + ETA (I-1,J ,bi,bj)) |
103 |
etaMeanV (I,J) = |
104 |
& HALF*(ETA (I,J,bi,bj) + ETA (I ,J-1,bi,bj)) |
105 |
etaMeanZ (I,J) = QUART * |
106 |
& ( eta(I ,J,bi,bj) + eta(I ,J-1,bi,bj) |
107 |
& + eta(I-1,J,bi,bj) + eta(I-1,J-1,bi,bj) ) |
108 |
dUdx(I,J) = ( uIce(I+1,J,1,bi,bj) - uIce(I,J,1,bi,bj) ) |
109 |
& * _recip_dxF(I,J,bi,bj) |
110 |
dUdy(I,J) = ( uIce(I,J+1,1,bi,bj) - uIce(I,J,1,bi,bj) ) |
111 |
& * _recip_dyU(I,J+1,bi,bj) |
112 |
dVdx(I,J) = ( vIce(I+1,J,1,bi,bj) - vIce(I,J,1,bi,bj) ) |
113 |
& * _recip_dxV(I+1,J,bi,bj) |
114 |
dVdy(I,J) = ( vIce(I,J+1,1,bi,bj) - vIce(I,J,1,bi,bj) ) |
115 |
& * _recip_dyF(I,J,bi,bj) |
116 |
ENDDO |
117 |
ENDDO |
118 |
DO J = 1,sNy |
119 |
DO I = 1,sNx |
120 |
C First FX = (d/dx)*sigma |
121 |
C + d/dx[ eta+zeta d/dx ] U |
122 |
FX = _recip_dxC(I,J,bi,bj) * |
123 |
& ( etaPlusZeta(I ,J) * dUdx(I ,J) |
124 |
& - etaPlusZeta(I-1,J) * dUdx(I-1,J) ) |
125 |
C + (d/dy)[eta*(d/dy + tanphi/a)] U (also on UVRT1/2) |
126 |
FX = FX + _recip_dyG(I,J,bi,bj) * ( |
127 |
& ( etaMeanZ(I,J+1) * dUdy(I,J+1) |
128 |
& - etaMeanZ(I,J ) * dUdy(I,J ) |
129 |
& ) |
130 |
& - ( etaMeanZ(I,J+1) |
131 |
& * ( uIce(I,J+1,1,bi,bj)+uIce(I,J,1,bi,bj) ) |
132 |
& - etaMeanZ(I,J ) |
133 |
& * ( uIce(I,J-1,1,bi,bj)+uIce(I,J,1,bi,bj) ) ) |
134 |
& * 0.5 _d 0 * _tanPhiAtU(I,J,bi,bj) |
135 |
& * recip_rSphere ) |
136 |
C - 2*eta*(tanphi/a) * ( tanphi/a ) U |
137 |
FX = FX - TWO * uIce(I,J,1,bi,bj) |
138 |
& * etaMeanU(I,J)*recip_rSphere*recip_rSphere |
139 |
& * _tanPhiAtU(I,J,bi,bj) * _tanPhiAtU(I,J,bi,bj) |
140 |
C + d/dx[ (zeta-eta) dV/dy] |
141 |
FX = FX + |
142 |
& ( zetaMinusEta(I ,J ) * dVdy(I ,J ) |
143 |
& - zetaMinusEta(I-1,J ) * dVdy(I-1,J ) |
144 |
& ) * _recip_dxC(I,J,bi,bj) |
145 |
C + d/dy[ eta dV/x ] |
146 |
FX = FX + ( |
147 |
& etaMeanZ(I,J+1) |
148 |
& * ( vIce(I ,J+1,1,bi,bj) - vIce(I-1,J+1,1,bi,bj) ) |
149 |
& * _recip_dxV(I,J+1,bi,bj) |
150 |
& - etaMeanZ(I,J ) |
151 |
& * ( vIce(I ,J,1,bi,bj) - vIce(I-1,J,1,bi,bj) ) |
152 |
& * _recip_dxV(I,J,bi,bj) |
153 |
& ) * _recip_dyG(I,J,bi,bj) |
154 |
C - d/dx[ (eta+zeta) * v * (tanphi/a) ] |
155 |
FX = FX - ( |
156 |
& etaPlusZeta(I ,J) |
157 |
& * 0.5 * (vIce(I ,J,1,bi,bj)+vIce(I ,J+1,1,bi,bj)) |
158 |
& * 0.5 * ( _tanPhiAtU(I ,J,bi,bj) |
159 |
& + _tanPhiAtU(I+1,J,bi,bj) ) |
160 |
& - etaPlusZeta(I-1,J) * |
161 |
& * 0.5 * (vIce(I-1,J,1,bi,bj)+vIce(I-1,J+1,1,bi,bj)) |
162 |
& * 0.5 * ( _tanPhiAtU(I-1,J,bi,bj) |
163 |
& + _tanPhiAtU(I ,J,bi,bj) ) |
164 |
& )* _recip_dxC(I,J,bi,bj)*recip_rSphere |
165 |
C - 2*eta*(tanphi/a) * dV/dx |
166 |
FX = FX |
167 |
& -TWO * etaMeanU(I,J) * _tanPhiAtV(I,J,bi,bj) |
168 |
& *recip_rSphere |
169 |
& *(vIce(I ,J,1,bi,bj) + vIce(I ,J+1,1,bi,bj) |
170 |
& - vIce(I-1,J,1,bi,bj) - vIce(I-1,J+1,1,bi,bj)) |
171 |
& * _recip_dxC(I,J,bi,bj) |
172 |
C - (d/dx) P/2 |
173 |
FX = _maskW(I,J,1,bi,bj) * ( FX - _recip_dxC(I,J,bi,bj) |
174 |
& * ( press(I,J,bi,bj) - press(I-1,J,bi,bj) ) ) |
175 |
C |
176 |
C then FY = (d/dy)*sigma |
177 |
C + d/dy [(eta+zeta) d/dy] V |
178 |
FY = _recip_dyC(I,J,bi,bj) * |
179 |
& ( dVdy(I,J ) * etaPlusZeta(I,J ) |
180 |
& - dVdy(I,J-1) * etaPlusZeta(I,J-1) ) |
181 |
C + d/dx [eta d/dx] V |
182 |
FY = FY + _recip_dxC(I,J,bi,bj) * |
183 |
& ( eta(I ,J,bi,bj) * dVdx(I ,J) |
184 |
& - eta(I-1,J,bi,bj) * dVdx(I-1,J) ) |
185 |
C - d/dy [(zeta-eta) tanphi/a] V |
186 |
FY = FY - _recip_dyC(I,J,bi,bj) * recip_rSphere * ( |
187 |
& zetaMinusEta(I,J ) * tanPhiAtU(I,J ,bi,bj) |
188 |
& * 0.5 * ( vIce(I,J,1,bi,bj) + vIce(I,J+1,1,bi,bj)) |
189 |
& - zetaMinusEta(I,J-1) * tanPhiAtU(I,J-1,bi,bj) |
190 |
& * 0.5 * ( vIce(I,J,1,bi,bj) + vIce(I,J-1,1,bi,bj)) ) |
191 |
C 2*eta tanphi/a ( - tanphi/a - d/dy) V |
192 |
FY = FY - TWO*etaMeanV(I,J) * recip_rSphere |
193 |
& * _tanPhiAtV(I,J,bi,bj) * ( |
194 |
& _tanPhiAtV(I,J,bi,bj) * recip_rSphere |
195 |
& + _recip_dyC(I,J,bi,bj) * |
196 |
& ( 0.5 * ( vIce(I,J,1,bi,bj) + vIce(I,J+1,1,bi,bj)) |
197 |
& - 0.5 * ( vIce(I,J,1,bi,bj) + vIce(I,J-1,1,bi,bj)) ) ) |
198 |
C + d/dy[ (zeta-eta) dU/dx ] |
199 |
FY = FY + |
200 |
& ( zetaMinusEta(I,J )*dUdx(I,J ) |
201 |
& - zetaMinusEta(I,J-1)*dUdx(I,J-1) ) |
202 |
& * _recip_dyC(I,J,bi,bj) |
203 |
C + d/dx[ eta dU/dy ] |
204 |
FY = FY + _recip_dxG(I,J,bi,bj) * |
205 |
& ( etaMeanZ(I+1,J) * dUdy(I+1,J) |
206 |
& - etaMeanZ(I ,J) * dUdy(I ,J) ) |
207 |
C + d/dx[ eta * (tanphi/a) * U ] |
208 |
FY = FY + ( |
209 |
& etaMeanZ(I+1,J) * 0.5 * |
210 |
& ( uIce(I+1,J ,1,bi,bj) * _tanPhiAtU(I+1,J ,bi,bj) |
211 |
& + uIce(I+1,J-1,1,bi,bj) * _tanPhiAtU(I+1,J-1,bi,bj) ) |
212 |
& - etaMeanZ(I ,J) * 0.5 * |
213 |
& ( uIce(I ,J ,1,bi,bj) * _tanPhiAtU(I ,J ,bi,bj) |
214 |
& + uIce(I ,J-1,1,bi,bj) * _tanPhiAtU(I ,J ,bi,bj) ) |
215 |
& ) * _recip_dxG(I,J,bi,bj)*recip_rSphere |
216 |
C + 2*eta*(tanphi/a) dU/dx |
217 |
FY = FY + |
218 |
& TWO * etaMeanV(I,J)*TWO * _tanPhiAtV(I,J,bi,bj) |
219 |
& * ( uIce(I+1,J,1,bi,bj)+uIce(I+1,J-1,1,bi,bj) |
220 |
& - uIce(I ,J,1,bi,bj)-uIce(I ,J-1,1,bi,bj) ) |
221 |
& * _recip_dxG(I,J,bi,bj) * recip_rSphere |
222 |
C - (d/dy) P/2 |
223 |
FY = _maskS(I,J,1,bi,bj) * ( FY - _recip_dyC(I,J,bi,bj) |
224 |
& * ( press(I,J,bi,bj) - press(I,J-1,bi,bj) ) ) |
225 |
C |
226 |
C recompute wind stress over ice (done already in seaice_dynsolver, |
227 |
C but not saved) |
228 |
fuIce = 0.5 _d 0 * |
229 |
& ( DAIRN(I ,J,bi,bj)*( |
230 |
& COSWIN*uWind(I ,J,bi,bj) |
231 |
& -SIGN(SINWIN, _fCori(I ,J,bi,bj))*vWind(I ,J,bi,bj) ) |
232 |
& + DAIRN(I-1,J,bi,bj)*( |
233 |
& COSWIN*uWind(I-1,J,bi,bj) |
234 |
& -SIGN(SINWIN, _fCori(I-1,J,bi,bj))*vWind(I-1,J,bi,bj) ) |
235 |
& ) |
236 |
fvIce = 0.5 _d 0 * |
237 |
& ( DAIRN(I,J ,bi,bj)*( |
238 |
& SIGN(SINWIN, _fCori(I ,J,bi,bj))*uWind(I,J ,bi,bj) |
239 |
& +COSWIN*vWind(I,J ,bi,bj) ) |
240 |
& + DAIRN(I,J-1,bi,bj)*( |
241 |
& SIGN(SINWIN, _fCori(I,J-1,bi,bj))*uWind(I,J-1,bi,bj) |
242 |
& +COSWIN*vWind(I,J-1,bi,bj) ) |
243 |
& ) |
244 |
C average wind stress over ice and ocean and apply averaged wind |
245 |
C stress and internal ice stresses to surface layer of ocean |
246 |
areaW = 0.5 * (AREA(I,J,1,bi,bj) + AREA(I-1,J,1,bi,bj)) |
247 |
& * SEAICEstressFactor |
248 |
areaS = 0.5 * (AREA(I,J,1,bi,bj) + AREA(I,J-1,1,bi,bj)) |
249 |
& * SEAICEstressFactor |
250 |
fu(I,J,bi,bj)=(ONE-areaW)*fu(I,J,bi,bj)+areaW*fuIce |
251 |
& + FX * SEAICEstressFactor |
252 |
fv(I,J,bi,bj)=(ONE-areaS)*fv(I,J,bi,bj)+areaS*fvIce |
253 |
& + FY * SEAICEstressFactor |
254 |
END DO |
255 |
END DO |
256 |
ENDDO |
257 |
ENDDO |
258 |
ELSE |
259 |
|
260 |
C-- Compute ice-affected wind stress (interpolate to U/V-points) |
261 |
C by averaging wind stress and ice-ocean stress according to |
262 |
C ice cover |
263 |
DO bj=myByLo(myThid),myByHi(myThid) |
264 |
DO bi=myBxLo(myThid),myBxHi(myThid) |
265 |
DO j=1,sNy |
266 |
DO i=1,sNx |
267 |
fuIce=HALF*( DWATN(I,J,bi,bj)+DWATN(I,J+1,bi,bj) )* |
268 |
& COSWAT * |
269 |
& ( UICE(I,J,1,bi,bj)-GWATX(I,J,bi,bj) ) |
270 |
& - SIGN(SINWAT, _fCori(I,J,bi,bj)) * 0.5 _d 0 * |
271 |
& ( DWATN(I ,J,bi,bj) * |
272 |
& 0.5 _d 0*(vIce(I ,J ,1,bi,bj)-GWATY(I ,J ,bi,bj) |
273 |
& +vIce(I ,J+1,1,bi,bj)-GWATY(I ,J+1,bi,bj)) |
274 |
& + DWATN(I-1,J,bi,bj) * |
275 |
& 0.5 _d 0*(vIce(I-1,J ,1,bi,bj)-GWATY(I-1,J ,bi,bj) |
276 |
& +vIce(I-1,J+1,1,bi,bj)-GWATY(I-1,J+1,bi,bj)) |
277 |
& ) |
278 |
fvIce=HALF*( DWATN(I,J,bi,bj)+DWATN(I+1,J,bi,bj) )* |
279 |
& COSWAT * |
280 |
& ( VICE(I,J,1,bi,bj)-GWATY(I,J,bi,bj) ) |
281 |
& + SIGN(SINWAT, _fCori(I,J,bi,bj)) * 0.5 _d 0 * |
282 |
& ( DWATN(I,J ,bi,bj) * |
283 |
& 0.5 _d 0*(uIce(I ,J ,1,bi,bj)-GWATX(I ,J ,bi,bj) |
284 |
& +uIce(I+1,J ,1,bi,bj)-GWATX(I+1,J ,bi,bj)) |
285 |
& + DWATN(I,J-1,bi,bj) * |
286 |
& 0.5 _d 0*(uIce(I ,J-1,1,bi,bj)-GWATX(I ,J-1,bi,bj) |
287 |
& +uIce(I+1,J-1,1,bi,bj)-GWATX(I+1,J-1,bi,bj)) |
288 |
& ) |
289 |
areaW = 0.5 _d 0 * (AREA(I,J,1,bi,bj) + AREA(I-1,J,1,bi,bj)) |
290 |
& * SEAICEstressFactor |
291 |
areaS = 0.5 _d 0 * (AREA(I,J,1,bi,bj) + AREA(I,J-1,1,bi,bj)) |
292 |
& * SEAICEstressFactor |
293 |
fu(I,J,bi,bj)=(ONE-areaW)*fu(I,J,bi,bj)+areaW*fuIce |
294 |
fv(I,J,bi,bj)=(ONE-areaS)*fv(I,J,bi,bj)+areaS*fvIce |
295 |
ENDDO |
296 |
ENDDO |
297 |
ENDDO |
298 |
ENDDO |
299 |
ENDIF |
300 |
CALL EXCH_UV_XY_RS(fu, fv, .TRUE., myThid) |
301 |
|
302 |
#endif /* not SEAICE_CGRID */ |
303 |
|
304 |
RETURN |
305 |
END |