| 1 | MODULE solsor |
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| 2 | !!====================================================================== |
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| 3 | !! *** MODULE solsor |
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| 4 | !! Ocean solver : Successive Over-Relaxation solver |
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| 5 | !!===================================================================== |
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| 6 | |
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| 7 | !!---------------------------------------------------------------------- |
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| 8 | !! sol_sor : Successive Over-Relaxation solver |
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| 9 | !!---------------------------------------------------------------------- |
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| 10 | !! * Modules used |
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| 11 | USE oce ! ocean dynamics and tracers variables |
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| 12 | USE dom_oce ! ocean space and time domain variables |
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| 13 | USE zdf_oce ! ocean vertical physics variables |
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| 14 | USE sol_oce ! solver variables |
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| 15 | USE in_out_manager ! I/O manager |
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| 16 | USE lib_mpp ! distributed memory computing |
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| 17 | USE lbclnk ! ocean lateral boundary conditions (or mpp link) |
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| 18 | |
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| 19 | IMPLICIT NONE |
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| 20 | PRIVATE |
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| 21 | |
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| 22 | !! * Routine accessibility |
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| 23 | PUBLIC sol_sor ! ??? |
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| 24 | |
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| 25 | !!---------------------------------------------------------------------- |
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| 26 | !! OPA 9.0 , LODYC-IPSL (2003) |
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| 27 | !!---------------------------------------------------------------------- |
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| 28 | |
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| 29 | CONTAINS |
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| 30 | |
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| 31 | SUBROUTINE sol_sor( kindic ) |
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| 32 | !!---------------------------------------------------------------------- |
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| 33 | !! *** ROUTINE sol_sor *** |
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| 34 | !! |
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| 35 | !! ** Purpose : Solve the ellipic equation for the barotropic stream |
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| 36 | !! function system (lk_dynspg_rl=T) or the transport divergence |
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| 37 | !! system (lk_dynspg_fsc=T) using a successive-over-relaxation |
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| 38 | !! method. |
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| 39 | !! In the former case, the barotropic stream function trend has a |
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| 40 | !! zero boundary condition along all coastlines (i.e. continent |
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| 41 | !! as well as islands) while in the latter the boundary condition |
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| 42 | !! specification is not required. |
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| 43 | !! |
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| 44 | !! ** Method : Successive-over-relaxation method using the red-black |
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| 45 | !! technique. The former technique used was not compatible with |
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| 46 | !! the north-fold boundary condition used in orca configurations. |
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| 47 | !! |
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| 48 | !! References : |
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| 49 | !! Madec et al. 1988, Ocean Modelling, issue 78, 1-6. |
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| 50 | !! |
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| 51 | !! History : |
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| 52 | !! ! 90-10 (G. Madec) Original code |
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| 53 | !! ! 91-11 (G. Madec) |
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| 54 | !! 7.1 ! 93-04 (G. Madec) time filter |
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| 55 | !! ! 96-05 (G. Madec) merge sor and pcg formulations |
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| 56 | !! ! 96-11 (A. Weaver) correction to preconditioning |
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| 57 | !! 8.5 ! 02-08 (G. Madec) F90: Free form |
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| 58 | !! ! 03-02 (C. Deltel) Red-Black SOR <== Not done yet!!! |
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| 59 | !! ************* |
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| 60 | !!---------------------------------------------------------------------- |
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| 61 | !! * Arguments |
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| 62 | INTEGER, INTENT( inout ) :: kindic ! solver indicator, < 0 if the conver- |
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| 63 | ! ! gence is not reached: the model is |
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| 64 | ! ! stopped in step |
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| 65 | ! ! set to zero before the call of solsor |
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| 66 | |
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| 67 | !! * Local declarations |
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| 68 | INTEGER :: ji, jj, jn ! dummy loop indices |
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| 69 | !!---------------------------------------------------------------------- |
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| 70 | |
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| 71 | ! ! ============== |
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| 72 | DO jn = 1, nmax ! Iterative loop |
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| 73 | ! ! ============== |
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| 74 | |
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| 75 | CALL lbc_lnk( gcx, c_solver_pt, 1. ) ! applied the lateral boubary conditions |
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| 76 | |
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| 77 | ! Residus |
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| 78 | ! ------- |
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| 79 | DO jj = 2, jpjm1 |
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| 80 | DO ji = 2, jpim1 |
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| 81 | gcr(ji,jj) = gcb(ji,jj ) - gcx(ji ,jj ) & |
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| 82 | - gcp(ji,jj,1) * gcx(ji ,jj-1) & |
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| 83 | - gcp(ji,jj,2) * gcx(ji-1,jj ) & |
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| 84 | - gcp(ji,jj,3) * gcx(ji+1,jj ) & |
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| 85 | - gcp(ji,jj,4) * gcx(ji ,jj+1) |
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| 86 | END DO |
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| 87 | END DO |
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| 88 | CALL lbc_lnk( gcr, c_solver_pt, 1. ) ! applied the lateral boubary conditions |
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| 89 | |
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| 90 | ! Successive over relaxation |
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| 91 | DO jj = 2, jpj |
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| 92 | DO ji = 1, jpi |
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| 93 | gcr(ji,jj) = gcr(ji,jj) - sor * gcp(ji,jj,1) * gcr(ji,jj-1) |
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| 94 | END DO |
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| 95 | DO ji = 2, jpi |
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| 96 | gcr(ji,jj) = gcr(ji,jj) - sor * gcp(ji,jj,2) * gcr(ji-1,jj) |
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| 97 | END DO |
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| 98 | END DO |
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| 99 | |
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| 100 | ! gcx guess |
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| 101 | DO jj = 2, jpjm1 |
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| 102 | DO ji = 1, jpi |
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| 103 | gcx(ji,jj) = ( gcx(ji,jj) + sor * gcr(ji,jj) ) * bmask(ji,jj) |
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| 104 | END DO |
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| 105 | END DO |
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| 106 | CALL lbc_lnk( gcx, c_solver_pt, 1. ) |
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| 107 | |
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| 108 | ! relative precision |
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| 109 | rnorme = SUM( gcr(:,:) * gcdmat(:,:) * gcr(:,:) ) |
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| 110 | IF( lk_mpp ) CALL mpp_sum( rnorme ) ! sum over the global domain |
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| 111 | |
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| 112 | ! test of convergence |
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| 113 | ! old test (either res<resmax or jn=nmax) |
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| 114 | ! IF( res < resmax .OR. jn == nmax ) THEN |
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| 115 | ! relative precision |
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| 116 | IF( rnorme < epsr .OR. jn == nmax ) THEN |
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| 117 | res = SQRT( rnorme ) |
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| 118 | niter = jn |
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| 119 | ncut = 999 |
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| 120 | ENDIF |
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| 121 | |
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| 122 | !**** |
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| 123 | ! IF(lwp)WRITE(numsol,9300) jn, res, sqrt( epsr ) / eps |
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| 124 | 9300 FORMAT(' niter :',i4,' res :',e20.10,' b :',e20.10) |
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| 125 | !**** |
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| 126 | |
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| 127 | ! indicator of non-convergence or explosion |
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| 128 | IF( jn == nmax .OR. SQRT(epsr)/eps > 1.e+20 ) kindic = -2 |
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| 129 | IF( ncut == 999 ) GOTO 999 |
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| 130 | |
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| 131 | ! ! ===================== |
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| 132 | END DO ! END of iterative loop |
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| 133 | ! ! ===================== |
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| 134 | |
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| 135 | 999 CONTINUE |
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| 136 | |
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| 137 | |
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| 138 | ! Output in gcx |
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| 139 | ! ------------- |
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| 140 | |
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| 141 | CALL lbc_lnk( gcx, c_solver_pt, 1. ) ! boundary conditions (est-ce necessaire? je ne crois pas!!!!) |
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| 142 | |
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| 143 | END SUBROUTINE sol_sor |
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| 144 | |
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| 145 | !!===================================================================== |
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| 146 | END MODULE solsor |
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