| 1 |
C $Header: /u/gcmpack/MITgcm/pkg/seaice/seaice_jfnk.F,v 1.1 2012/10/16 07:00:21 mlosch Exp $ |
| 2 |
C $Name: $ |
| 3 |
|
| 4 |
#include "SEAICE_OPTIONS.h" |
| 5 |
|
| 6 |
CBOP |
| 7 |
C !ROUTINE: SEAICE_JFNK |
| 8 |
C !INTERFACE: |
| 9 |
SUBROUTINE SEAICE_JFNK( myTime, myIter, myThid ) |
| 10 |
|
| 11 |
C !DESCRIPTION: \bv |
| 12 |
C *==========================================================* |
| 13 |
C | SUBROUTINE SEAICE_JFKF |
| 14 |
C | o Ice dynamics using a Jacobian-free Newton-Krylov solver |
| 15 |
C | following J.-F. Lemieux et al. Improving the numerical |
| 16 |
C | convergence of viscous-plastic sea ice models with the |
| 17 |
C | Jacobian-free Newton-Krylov method. J. Comp. Phys. 229, |
| 18 |
C | 2840-2852 (2010). |
| 19 |
C | o The logic follows JFs code. |
| 20 |
C *==========================================================* |
| 21 |
C | written by Martin Losch, Oct 2012 |
| 22 |
C *==========================================================* |
| 23 |
C \ev |
| 24 |
|
| 25 |
C !USES: |
| 26 |
IMPLICIT NONE |
| 27 |
|
| 28 |
C === Global variables === |
| 29 |
#include "SIZE.h" |
| 30 |
#include "EEPARAMS.h" |
| 31 |
#include "PARAMS.h" |
| 32 |
#include "DYNVARS.h" |
| 33 |
#include "GRID.h" |
| 34 |
#include "SEAICE_SIZE.h" |
| 35 |
#include "SEAICE_PARAMS.h" |
| 36 |
#include "SEAICE.h" |
| 37 |
|
| 38 |
#ifdef ALLOW_AUTODIFF_TAMC |
| 39 |
# include "tamc.h" |
| 40 |
#endif |
| 41 |
|
| 42 |
C !INPUT/OUTPUT PARAMETERS: |
| 43 |
C === Routine arguments === |
| 44 |
C myTime :: Simulation time |
| 45 |
C myIter :: Simulation timestep number |
| 46 |
C myThid :: my Thread Id. number |
| 47 |
_RL myTime |
| 48 |
INTEGER myIter |
| 49 |
INTEGER myThid |
| 50 |
|
| 51 |
#if ( (defined SEAICE_CGRID) && \ |
| 52 |
(defined SEAICE_ALLOW_JFNK) && \ |
| 53 |
(defined SEAICE_ALLOW_DYNAMICS) ) |
| 54 |
|
| 55 |
C i,j,bi,bj :: loop indices |
| 56 |
INTEGER i,j,bi,bj |
| 57 |
C loop indices |
| 58 |
INTEGER newtonIter, newtonIterFail |
| 59 |
INTEGER krylovIter, krylovIterFail |
| 60 |
INTEGER totalKrylovIter |
| 61 |
C FGMRES flag that indicates what to do next |
| 62 |
INTEGER iCode |
| 63 |
_RL JFNKresidual, JFNKresidualTile(nSx,nSy) |
| 64 |
_RL JFNKresidualKm1 |
| 65 |
C parameters to compute convergence criterion |
| 66 |
_RL phi_e, alp_e, JFNKgamma_lin |
| 67 |
_RL FGMRESeps |
| 68 |
_RL JFNKtol |
| 69 |
C |
| 70 |
_RL recip_deltaT |
| 71 |
LOGICAL JFNKconverged, krylovConverged |
| 72 |
CHARACTER*(MAX_LEN_MBUF) msgBuf |
| 73 |
C |
| 74 |
C u/vIceRes :: residual of sea-ice momentum equations |
| 75 |
_RL uIceRes(1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
| 76 |
_RL vIceRes(1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
| 77 |
C du/vIce :: ice velocity increment to be added to u/vIce |
| 78 |
_RL duIce (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
| 79 |
_RL dvIce (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
| 80 |
C precomputed (= constant per Newton iteration) versions of |
| 81 |
C zeta, eta, and DWATN, press |
| 82 |
_RL zetaPre (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
| 83 |
_RL etaPre (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
| 84 |
_RL dwatPre (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
| 85 |
_RL pressPre(1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
| 86 |
CEOP |
| 87 |
|
| 88 |
C Initialise |
| 89 |
newtonIter = 0 |
| 90 |
newtonIterFail = 0 |
| 91 |
krylovIterFail = 0 |
| 92 |
totalKrylovIter = 0 |
| 93 |
JFNKconverged = .FALSE. |
| 94 |
JFNKtol = 0. _d 0 |
| 95 |
JFNKresidual = 0. _d 0 |
| 96 |
JFNKresidualKm1 = 0. _d 0 |
| 97 |
FGMRESeps = 0. _d 0 |
| 98 |
recip_deltaT = 1. _d 0 / SEAICE_deltaTdyn |
| 99 |
C |
| 100 |
DO bj=myByLo(myThid),myByHi(myThid) |
| 101 |
DO bi=myBxLo(myThid),myBxHi(myThid) |
| 102 |
DO J=1-Oly,sNy+Oly |
| 103 |
DO I=1-Olx,sNx+Olx |
| 104 |
uIceRes(I,J,bi,bj) = 0. _d 0 |
| 105 |
vIceRes(I,J,bi,bj) = 0. _d 0 |
| 106 |
duIce (I,J,bi,bj) = 0. _d 0 |
| 107 |
dvIce (I,J,bi,bj) = 0. _d 0 |
| 108 |
uIceNm1(I,J,bi,bj) = uIce(I,J,bi,bj) |
| 109 |
vIceNm1(I,J,bi,bj) = vIce(I,J,bi,bj) |
| 110 |
ENDDO |
| 111 |
ENDDO |
| 112 |
C Compute things that do no change during the Newton iteration: |
| 113 |
C sea-surface tilt and wind stress: |
| 114 |
C FORCEX/Y0 - mass*(u/vIceNm1)/deltaT |
| 115 |
DO J=1-Oly,sNy+Oly |
| 116 |
DO I=1-Olx,sNx+Olx |
| 117 |
FORCEX(I,J,bi,bj) = FORCEX0(I,J,bi,bj) |
| 118 |
& + seaiceMassU(I,J,bi,bj)*uIceNm1(I,J,bi,bj)*recip_deltaT |
| 119 |
FORCEY(I,J,bi,bj) = FORCEY0(I,J,bi,bj) |
| 120 |
& + seaiceMassV(I,J,bi,bj)*vIceNm1(I,J,bi,bj)*recip_deltaT |
| 121 |
ENDDO |
| 122 |
ENDDO |
| 123 |
ENDDO |
| 124 |
ENDDO |
| 125 |
C Start nonlinear Newton iteration: outer loop iteration |
| 126 |
DO WHILE ( newtonIter.LT.SEAICEnewtonIterMax .AND. |
| 127 |
& .NOT.JFNKconverged ) |
| 128 |
newtonIter = newtonIter + 1 |
| 129 |
C Compute initial residual F(u), (includes computation of global |
| 130 |
C variables DWATN, zeta, and eta) |
| 131 |
CALL SEAICE_CALC_RESIDUAL( |
| 132 |
I uIce, vIce, |
| 133 |
O uIceRes, vIceRes, |
| 134 |
I newtonIter, 0, myTime, myIter, myThid ) |
| 135 |
C local copies of precomputed coefficients that are to stay |
| 136 |
C constant for the preconditioner |
| 137 |
DO bj=myByLo(myThid),myByHi(myThid) |
| 138 |
DO bi=myBxLo(myThid),myBxHi(myThid) |
| 139 |
DO j=1-Oly,sNy+Oly |
| 140 |
DO i=1-Olx,sNx+Olx |
| 141 |
zetaPre(I,J,bi,bj) = zeta(I,J,bi,bj) |
| 142 |
etaPre(I,J,bi,bj) = eta(I,J,bi,bj) |
| 143 |
dwatPre(I,J,bi,bj) = DWATN(I,J,bi,bj) |
| 144 |
pressPre(I,J,bi,bj) = press(I,J,bi,bj) |
| 145 |
ENDDO |
| 146 |
ENDDO |
| 147 |
ENDDO |
| 148 |
ENDDO |
| 149 |
C |
| 150 |
DO bj=myByLo(myThid),myByHi(myThid) |
| 151 |
DO bi=myBxLo(myThid),myBxHi(myThid) |
| 152 |
JFNKresidualTile(bi,bj) = 0. _d 0 |
| 153 |
DO J=1,sNy |
| 154 |
DO I=1,sNx |
| 155 |
#ifdef CG2D_SINGLECPU_SUM |
| 156 |
JFNKlocalBuf(I,J,bi,bj) = |
| 157 |
#else |
| 158 |
JFNKresidualTile(bi,bj) = JFNKresidualTile(bi,bj) + |
| 159 |
#endif |
| 160 |
& uIceRes(I,J,bi,bj)*uIceRes(I,J,bi,bj) + |
| 161 |
& vIceRes(I,J,bi,bj)*vIceRes(I,J,bi,bj) |
| 162 |
ENDDO |
| 163 |
ENDDO |
| 164 |
ENDDO |
| 165 |
ENDDO |
| 166 |
JFNKresidual = 0. _d 0 |
| 167 |
#ifdef CG2D_SINGLECPU_SUM |
| 168 |
CALL GLOBAL_SUM_SINGLECPU_RL( |
| 169 |
& JFNKlocalBuf,JFNKresidual, 0, 0, myThid) |
| 170 |
#else |
| 171 |
CALL GLOBAL_SUM_TILE_RL( JFNKresidualTile,JFNKresidual,myThid ) |
| 172 |
#endif |
| 173 |
JFNKresidual = SQRT(JFNKresidual) |
| 174 |
C compute convergence criterion for linear preconditioned FGMRES |
| 175 |
JFNKgamma_lin = JFNKgamma_lin_max |
| 176 |
IF ( newtonIter.GT.1.AND.newtonIter.LE.100 |
| 177 |
& .AND.JFNKresidual.LT.JFNKres_t ) THEN |
| 178 |
C Eisenstat, 1996, equ.(2.6) |
| 179 |
phi_e = 1. _d 0 |
| 180 |
alp_e = 1. _d 0 |
| 181 |
JFNKgamma_lin = phi_e*( JFNKresidual/JFNKresidualKm1 )**alp_e |
| 182 |
JFNKgamma_lin = min(JFNKgamma_lin_max, JFNKgamma_lin) |
| 183 |
JFNKgamma_lin = max(JFNKgamma_lin_min, JFNKgamma_lin) |
| 184 |
ENDIF |
| 185 |
C save the residual for the next iteration |
| 186 |
JFNKresidualKm1 = JFNKresidual |
| 187 |
C |
| 188 |
C The Krylov iteration using FGMRES, the preconditioner is LSOR |
| 189 |
C for now. The code is adapted from SEAICE_LSR, but heavily stripped |
| 190 |
C down. |
| 191 |
C krylovIter is mapped into "its" in seaice_fgmres and is incremented |
| 192 |
C in that routine |
| 193 |
krylovIter = 0 |
| 194 |
iCode = 0 |
| 195 |
IF ( debugLevel.GE.debLevA ) THEN |
| 196 |
WRITE(msgBuf,'(2A,2(1XI6),2E12.5)') |
| 197 |
& ' S/R SEAICE_JFNK: newtonIter,', |
| 198 |
& ' total newtonIter, JFNKgamma_lin, initial norm = ', |
| 199 |
& newtonIter, SEAICEnewtonIterMax*myIter+newtonIter, |
| 200 |
& JFNKgamma_lin, JFNKresidual |
| 201 |
CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, |
| 202 |
& SQUEEZE_RIGHT, myThid ) |
| 203 |
ENDIF |
| 204 |
C |
| 205 |
JFNKconverged = JFNKresidual.LT.JFNKtol |
| 206 |
C |
| 207 |
C do Krylov loop only if convergence is not reached |
| 208 |
C |
| 209 |
IF ( .NOT.JFNKconverged ) THEN |
| 210 |
C |
| 211 |
C start Krylov iteration (FGMRES) |
| 212 |
C |
| 213 |
krylovConverged = .FALSE. |
| 214 |
FGMRESeps = JFNKgamma_lin * JFNKresidual |
| 215 |
DO WHILE ( .NOT.krylovConverged ) |
| 216 |
C solution vector sol = du/vIce |
| 217 |
C residual vector (rhs) Fu = u/vIceRes |
| 218 |
C output work vectors wk1, -> input work vector wk2 |
| 219 |
C |
| 220 |
CALL EXCH_UV_XY_RL( uIceRes, vIceRes,.TRUE.,myThid) |
| 221 |
CALL EXCH_UV_XY_RL( duIce, dvIce,.TRUE.,myThid) |
| 222 |
CALL SEAICE_FGMRES_DRIVER( |
| 223 |
I uIceRes, vIceRes, |
| 224 |
U duIce, dvIce, iCode, |
| 225 |
I FGMRESeps, |
| 226 |
I newtonIter, krylovIter, myTime, myIter, myThid ) |
| 227 |
C FGMRES returns iCode either asking for an new preconditioned vector |
| 228 |
C or product of matrix (Jacobian) times vector. For iCode = 0, terminate |
| 229 |
C iteration |
| 230 |
IF (iCode.EQ.1) THEN |
| 231 |
C Call preconditioner |
| 232 |
CALL SEAICE_PRECONDITIONER( |
| 233 |
U duIce, dvIce, |
| 234 |
I zetaPre, etaPre, dwatPre, pressPre, |
| 235 |
I newtonIter, krylovIter, myTime, myIter, myThid ) |
| 236 |
ELSEIF (iCode.GE.2) THEN |
| 237 |
C Compute Jacobian times vector |
| 238 |
CALL SEAICE_JACVEC( |
| 239 |
I uIce, vIce, uIceRes, vIceRes, |
| 240 |
U duIce, dvIce, |
| 241 |
I newtonIter, krylovIter, myTime, myIter, myThid ) |
| 242 |
ENDIF |
| 243 |
krylovConverged = iCode.EQ.0 |
| 244 |
C End of Krylov iterate |
| 245 |
ENDDO |
| 246 |
totalKrylovIter = totalKrylovIter + krylovIter |
| 247 |
C some output diagnostics |
| 248 |
IF ( debugLevel.GE.debLevA ) THEN |
| 249 |
WRITE(msgBuf,'(3(A,I6))') |
| 250 |
& ' S/R SEAICE_JFNK: Newton iterate / total = ', newtonIter, |
| 251 |
& ' / ', SEAICEnewtonIterMax*myIter+newtonIter, |
| 252 |
& ', Nb. of FGMRES iterations = ', krylovIter |
| 253 |
CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, |
| 254 |
& SQUEEZE_RIGHT, myThid ) |
| 255 |
ENDIF |
| 256 |
IF ( krylovIter.EQ.SEAICEkrylovIterMax ) THEN |
| 257 |
krylovIterFail = krylovIterFail + 1 |
| 258 |
ENDIF |
| 259 |
C Update linear solution vector and return to Newton iteration |
| 260 |
DO bj=myByLo(myThid),myByHi(myThid) |
| 261 |
DO bi=myBxLo(myThid),myBxHi(myThid) |
| 262 |
DO J=1-Oly,sNy+Oly |
| 263 |
DO I=1-Olx,sNx+Olx |
| 264 |
uIce(I,J,bi,bj) = uIce(I,J,bi,bj)+duIce(I,J,bi,bj) |
| 265 |
vIce(I,J,bi,bj) = vIce(I,J,bi,bj)+dvIce(I,J,bi,bj) |
| 266 |
ENDDO |
| 267 |
ENDDO |
| 268 |
ENDDO |
| 269 |
ENDDO |
| 270 |
C Set the stopping criterion for the Newton iteration |
| 271 |
IF ( newtonIter .EQ. 1 ) JFNKtol=JFNKgamma_nonlin*JFNKresidual |
| 272 |
ENDIF |
| 273 |
C end of Newton iterate |
| 274 |
ENDDO |
| 275 |
C some output diagnostics |
| 276 |
IF ( debugLevel.GE.debLevA ) THEN |
| 277 |
C Record failure |
| 278 |
IF ( newtonIter .EQ. SEAICEnewtonIterMax ) THEN |
| 279 |
newtonIterFail = newtonIterFail + 1 |
| 280 |
WRITE(msgBuf,'(A,I10)') |
| 281 |
& ' S/R SEAICE_JFNK: JFNK did not converge in timestep ', |
| 282 |
& myIter |
| 283 |
CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, |
| 284 |
& SQUEEZE_RIGHT, myThid ) |
| 285 |
ENDIF |
| 286 |
IF ( krylovIterFail .GT. 0 ) THEN |
| 287 |
WRITE(msgBuf,'(A,I4,A,I10)') |
| 288 |
& ' S/R SEAICE_JFNK: FGMRES did not converge ', |
| 289 |
& krylovIterFail, ' times in timestep ', myIter |
| 290 |
CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, |
| 291 |
& SQUEEZE_RIGHT, myThid ) |
| 292 |
ENDIF |
| 293 |
WRITE(msgBuf,'(A,I6)') |
| 294 |
& ' S/R SEAICE_JFNK: Total number FGMRES iterations = ', |
| 295 |
& totalKrylovIter |
| 296 |
CALL PRINT_MESSAGE( msgBuf, standardMessageUnit, |
| 297 |
& SQUEEZE_RIGHT, myThid ) |
| 298 |
|
| 299 |
ENDIF |
| 300 |
|
| 301 |
#endif /* SEAICE_ALLOW_DYNAMICS and SEAICE_CGRID and SEAICE_ALLOW_JFNK */ |
| 302 |
|
| 303 |
RETURN |
| 304 |
END |
Parent Directory
| 
Revision Log
| 
Revision Graph