[825] | 1 | MODULE limrhg |
---|
| 2 | !!====================================================================== |
---|
| 3 | !! *** MODULE limrhg *** |
---|
[834] | 4 | !! Ice rheology : sea ice rheology |
---|
[825] | 5 | !!====================================================================== |
---|
[1244] | 6 | !! History : - ! 2007-03 (M.A. Morales Maqueda, S. Bouillon) Original code |
---|
| 7 | !! 3.0 ! 2008-03 (M. Vancoppenolle) LIM3 |
---|
| 8 | !! - ! 2008-11 (M. Vancoppenolle, S. Bouillon, Y. Aksenov) add surface tilt in ice rheolohy |
---|
[2528] | 9 | !! 3.3 ! 2009-05 (G.Garric) addition of the lim2_evp cas |
---|
[3680] | 10 | !! 3.4 ! 2011-01 (A. Porter) dynamical allocation |
---|
[7646] | 11 | !! 3.5 ! 2012-08 (R. Benshila) AGRIF |
---|
| 12 | !! 3.6 ! 2016-06 (C. Rousset) Rewriting + landfast ice + possibility to use mEVP (Bouillon 2013) |
---|
[1244] | 13 | !!---------------------------------------------------------------------- |
---|
[7646] | 14 | #if defined key_lim3 |
---|
[825] | 15 | !!---------------------------------------------------------------------- |
---|
[7646] | 16 | !! 'key_lim3' LIM-3 sea-ice model |
---|
[825] | 17 | !!---------------------------------------------------------------------- |
---|
[3625] | 18 | !! lim_rhg : computes ice velocities |
---|
[825] | 19 | !!---------------------------------------------------------------------- |
---|
[3625] | 20 | USE phycst ! Physical constant |
---|
| 21 | USE oce , ONLY : snwice_mass, snwice_mass_b |
---|
| 22 | USE par_oce ! Ocean parameters |
---|
| 23 | USE dom_oce ! Ocean domain |
---|
| 24 | USE sbc_oce ! Surface boundary condition: ocean fields |
---|
| 25 | USE sbc_ice ! Surface boundary condition: ice fields |
---|
[7646] | 26 | USE ice ! ice variables |
---|
| 27 | USE limitd_me ! ice strength |
---|
[3625] | 28 | USE lbclnk ! Lateral Boundary Condition / MPP link |
---|
| 29 | USE lib_mpp ! MPP library |
---|
| 30 | USE wrk_nemo ! work arrays |
---|
| 31 | USE in_out_manager ! I/O manager |
---|
| 32 | USE prtctl ! Print control |
---|
| 33 | USE lib_fortran ! Fortran utilities (allows no signed zero when 'key_nosignedzero' defined) |
---|
[7646] | 34 | #if defined key_agrif |
---|
| 35 | USE agrif_lim3_interp |
---|
[3680] | 36 | #endif |
---|
[7646] | 37 | USE bdy_oce , ONLY: ln_bdy |
---|
| 38 | USE bdyice_lim |
---|
[825] | 39 | |
---|
| 40 | IMPLICIT NONE |
---|
| 41 | PRIVATE |
---|
| 42 | |
---|
[7646] | 43 | PUBLIC lim_rhg ! routine called by lim_dyn |
---|
[825] | 44 | |
---|
[868] | 45 | !! * Substitutions |
---|
| 46 | # include "vectopt_loop_substitute.h90" |
---|
[825] | 47 | !!---------------------------------------------------------------------- |
---|
[4161] | 48 | !! NEMO/LIM3 4.0 , UCL - NEMO Consortium (2011) |
---|
[1156] | 49 | !! $Id$ |
---|
[2528] | 50 | !! Software governed by the CeCILL licence (NEMOGCM/NEMO_CeCILL.txt) |
---|
[825] | 51 | !!---------------------------------------------------------------------- |
---|
| 52 | CONTAINS |
---|
| 53 | |
---|
[7646] | 54 | SUBROUTINE lim_rhg |
---|
[825] | 55 | !!------------------------------------------------------------------- |
---|
[834] | 56 | !! *** SUBROUTINE lim_rhg *** |
---|
| 57 | !! EVP-C-grid |
---|
[825] | 58 | !! |
---|
[834] | 59 | !! ** purpose : determines sea ice drift from wind stress, ice-ocean |
---|
[825] | 60 | !! stress and sea-surface slope. Ice-ice interaction is described by |
---|
[834] | 61 | !! a non-linear elasto-viscous-plastic (EVP) law including shear |
---|
| 62 | !! strength and a bulk rheology (Hunke and Dukowicz, 2002). |
---|
[825] | 63 | !! |
---|
[834] | 64 | !! The points in the C-grid look like this, dear reader |
---|
[825] | 65 | !! |
---|
[834] | 66 | !! (ji,jj) |
---|
| 67 | !! | |
---|
| 68 | !! | |
---|
| 69 | !! (ji-1,jj) | (ji,jj) |
---|
| 70 | !! --------- |
---|
| 71 | !! | | |
---|
| 72 | !! | (ji,jj) |------(ji,jj) |
---|
| 73 | !! | | |
---|
| 74 | !! --------- |
---|
| 75 | !! (ji-1,jj-1) (ji,jj-1) |
---|
[825] | 76 | !! |
---|
[834] | 77 | !! ** Inputs : - wind forcing (stress), oceanic currents |
---|
| 78 | !! ice total volume (vt_i) per unit area |
---|
| 79 | !! snow total volume (vt_s) per unit area |
---|
[825] | 80 | !! |
---|
[834] | 81 | !! ** Action : - compute u_ice, v_ice : the components of the |
---|
| 82 | !! sea-ice velocity vector |
---|
| 83 | !! - compute delta_i, shear_i, divu_i, which are inputs |
---|
| 84 | !! of the ice thickness distribution |
---|
[825] | 85 | !! |
---|
[834] | 86 | !! ** Steps : 1) Compute ice snow mass, ice strength |
---|
| 87 | !! 2) Compute wind, oceanic stresses, mass terms and |
---|
| 88 | !! coriolis terms of the momentum equation |
---|
| 89 | !! 3) Solve the momentum equation (iterative procedure) |
---|
| 90 | !! 4) Prevent high velocities if the ice is thin |
---|
| 91 | !! 5) Recompute invariants of the strain rate tensor |
---|
| 92 | !! which are inputs of the ITD, store stress |
---|
| 93 | !! for the next time step |
---|
| 94 | !! 6) Control prints of residual (convergence) |
---|
| 95 | !! and charge ellipse. |
---|
| 96 | !! The user should make sure that the parameters |
---|
[5123] | 97 | !! nn_nevp, elastic time scale and rn_creepl maintain stress state |
---|
[834] | 98 | !! on the charge ellipse for plastic flow |
---|
| 99 | !! e.g. in the Canadian Archipelago |
---|
| 100 | !! |
---|
[7646] | 101 | !! ** Notes : There is the possibility to use mEVP from Bouillon 2013 |
---|
| 102 | !! (by uncommenting some lines in part 3 and changing alpha and beta parameters) |
---|
| 103 | !! but this solution appears very unstable (see Kimmritz et al 2016) |
---|
| 104 | !! |
---|
[2528] | 105 | !! References : Hunke and Dukowicz, JPO97 |
---|
| 106 | !! Bouillon et al., Ocean Modelling 2009 |
---|
[7646] | 107 | !! Bouillon et al., Ocean Modelling 2013 |
---|
[2528] | 108 | !!------------------------------------------------------------------- |
---|
[7646] | 109 | INTEGER :: ji, jj ! dummy loop indices |
---|
| 110 | INTEGER :: jter ! local integers |
---|
[825] | 111 | CHARACTER (len=50) :: charout |
---|
| 112 | |
---|
[7646] | 113 | REAL(wp) :: zrhoco ! rau0 * rn_cio |
---|
| 114 | REAL(wp) :: zdtevp, z1_dtevp ! time step for subcycling |
---|
| 115 | REAL(wp) :: ecc2, z1_ecc2 ! square of yield ellipse eccenticity |
---|
| 116 | REAL(wp) :: zbeta, zalph1, z1_alph1, zalph2, z1_alph2 ! alpha and beta from Bouillon 2009 and 2013 |
---|
| 117 | REAL(wp) :: zm1, zm2, zm3, zmassU, zmassV ! ice/snow mass |
---|
| 118 | REAL(wp) :: zdelta, zp_delf, zds2, zdt, zdt2, zdiv, zdiv2 ! temporary scalars |
---|
| 119 | REAL(wp) :: zTauO, zTauB, zTauE, zCor, zvel ! temporary scalars |
---|
[825] | 120 | |
---|
[7646] | 121 | REAL(wp) :: zsig1, zsig2 ! internal ice stress |
---|
| 122 | REAL(wp) :: zresm ! Maximal error on ice velocity |
---|
| 123 | REAL(wp) :: zintb, zintn ! dummy argument |
---|
[3294] | 124 | |
---|
[7646] | 125 | REAL(wp), POINTER, DIMENSION(:,:) :: z1_e1t0, z1_e2t0 ! scale factors |
---|
| 126 | REAL(wp), POINTER, DIMENSION(:,:) :: zp_delt ! P/delta at T points |
---|
| 127 | ! |
---|
| 128 | REAL(wp), POINTER, DIMENSION(:,:) :: zaU , zaV ! ice fraction on U/V points |
---|
| 129 | REAL(wp), POINTER, DIMENSION(:,:) :: zmU_t, zmV_t ! ice/snow mass/dt on U/V points |
---|
| 130 | REAL(wp), POINTER, DIMENSION(:,:) :: zmf ! coriolis parameter at T points |
---|
| 131 | REAL(wp), POINTER, DIMENSION(:,:) :: zTauU_ia , ztauV_ia ! ice-atm. stress at U-V points |
---|
| 132 | REAL(wp), POINTER, DIMENSION(:,:) :: zspgU , zspgV ! surface pressure gradient at U/V points |
---|
| 133 | REAL(wp), POINTER, DIMENSION(:,:) :: v_oceU, u_oceV, v_iceU, u_iceV ! ocean/ice u/v component on V/U points |
---|
| 134 | REAL(wp), POINTER, DIMENSION(:,:) :: zfU , zfV ! internal stresses |
---|
| 135 | |
---|
| 136 | REAL(wp), POINTER, DIMENSION(:,:) :: zds ! shear |
---|
| 137 | REAL(wp), POINTER, DIMENSION(:,:) :: zs1, zs2, zs12 ! stress tensor components |
---|
| 138 | REAL(wp), POINTER, DIMENSION(:,:) :: zu_ice, zv_ice, zresr ! check convergence |
---|
| 139 | REAL(wp), POINTER, DIMENSION(:,:) :: zpice ! array used for the calculation of ice surface slope: |
---|
| 140 | ! ocean surface (ssh_m) if ice is not embedded |
---|
| 141 | ! ice top surface if ice is embedded |
---|
| 142 | REAL(wp), POINTER, DIMENSION(:,:) :: zswitchU, zswitchV ! dummy arrays |
---|
| 143 | REAL(wp), POINTER, DIMENSION(:,:) :: zmaskU, zmaskV ! mask for ice presence |
---|
| 144 | REAL(wp), POINTER, DIMENSION(:,:) :: zfmask, zwf ! mask at F points for the ice |
---|
[5123] | 145 | |
---|
[7646] | 146 | REAL(wp), PARAMETER :: zepsi = 1.0e-20_wp ! tolerance parameter |
---|
| 147 | REAL(wp), PARAMETER :: zmmin = 1._wp ! ice mass (kg/m2) below which ice velocity equals ocean velocity |
---|
| 148 | REAL(wp), PARAMETER :: zshlat = 2._wp ! boundary condition for sea-ice velocity (2=no slip ; 0=free slip) |
---|
[2528] | 149 | !!------------------------------------------------------------------- |
---|
[3294] | 150 | |
---|
[7646] | 151 | CALL wrk_alloc( jpi,jpj, z1_e1t0, z1_e2t0, zp_delt ) |
---|
| 152 | CALL wrk_alloc( jpi,jpj, zaU, zaV, zmU_t, zmV_t, zmf, zTauU_ia, ztauV_ia ) |
---|
| 153 | CALL wrk_alloc( jpi,jpj, zspgU, zspgV, v_oceU, u_oceV, v_iceU, u_iceV, zfU, zfV ) |
---|
| 154 | CALL wrk_alloc( jpi,jpj, zds, zs1, zs2, zs12, zu_ice, zv_ice, zresr, zpice ) |
---|
| 155 | CALL wrk_alloc( jpi,jpj, zswitchU, zswitchV, zmaskU, zmaskV, zfmask, zwf ) |
---|
[3294] | 156 | |
---|
[7646] | 157 | #if defined key_agrif |
---|
| 158 | CALL agrif_interp_lim3( 'U', 0, nn_nevp ) ! First interpolation of coarse values |
---|
| 159 | CALL agrif_interp_lim3( 'V', 0, nn_nevp ) |
---|
[2528] | 160 | #endif |
---|
[921] | 161 | ! |
---|
| 162 | !------------------------------------------------------------------------------! |
---|
[7646] | 163 | ! 0) mask at F points for the ice |
---|
[921] | 164 | !------------------------------------------------------------------------------! |
---|
[7646] | 165 | ! ocean/land mask |
---|
| 166 | DO jj = 1, jpjm1 |
---|
| 167 | DO ji = 1, jpim1 ! NO vector opt. |
---|
| 168 | zfmask(ji,jj) = tmask(ji,jj,1) * tmask(ji+1,jj,1) * tmask(ji,jj+1,1) * tmask(ji+1,jj+1,1) |
---|
| 169 | END DO |
---|
| 170 | END DO |
---|
| 171 | CALL lbc_lnk( zfmask, 'F', 1._wp ) |
---|
[825] | 172 | |
---|
[7646] | 173 | ! Lateral boundary conditions on velocity (modify zfmask) |
---|
[7753] | 174 | zwf(:,:) = zfmask(:,:) |
---|
[7646] | 175 | DO jj = 2, jpjm1 |
---|
| 176 | DO ji = fs_2, fs_jpim1 ! vector opt. |
---|
| 177 | IF( zfmask(ji,jj) == 0._wp ) THEN |
---|
| 178 | zfmask(ji,jj) = zshlat * MIN( 1._wp , MAX( zwf(ji+1,jj), zwf(ji,jj+1), zwf(ji-1,jj), zwf(ji,jj-1) ) ) |
---|
| 179 | ENDIF |
---|
[825] | 180 | END DO |
---|
| 181 | END DO |
---|
[7646] | 182 | DO jj = 2, jpjm1 |
---|
| 183 | IF( zfmask(1,jj) == 0._wp ) THEN |
---|
| 184 | zfmask(1 ,jj) = zshlat * MIN( 1._wp , MAX( zwf(2,jj), zwf(1,jj+1), zwf(1,jj-1) ) ) |
---|
| 185 | ENDIF |
---|
| 186 | IF( zfmask(jpi,jj) == 0._wp ) THEN |
---|
| 187 | zfmask(jpi,jj) = zshlat * MIN( 1._wp , MAX( zwf(jpi,jj+1), zwf(jpim1,jj), zwf(jpi,jj-1) ) ) |
---|
| 188 | ENDIF |
---|
| 189 | END DO |
---|
| 190 | DO ji = 2, jpim1 |
---|
| 191 | IF( zfmask(ji,1) == 0._wp ) THEN |
---|
| 192 | zfmask(ji,1 ) = zshlat * MIN( 1._wp , MAX( zwf(ji+1,1), zwf(ji,2), zwf(ji-1,1) ) ) |
---|
| 193 | ENDIF |
---|
| 194 | IF( zfmask(ji,jpj) == 0._wp ) THEN |
---|
| 195 | zfmask(ji,jpj) = zshlat * MIN( 1._wp , MAX( zwf(ji+1,jpj), zwf(ji-1,jpj), zwf(ji,jpjm1) ) ) |
---|
| 196 | ENDIF |
---|
| 197 | END DO |
---|
| 198 | CALL lbc_lnk( zfmask, 'F', 1._wp ) |
---|
[825] | 199 | |
---|
[7646] | 200 | !------------------------------------------------------------------------------! |
---|
| 201 | ! 1) define some variables and initialize arrays |
---|
| 202 | !------------------------------------------------------------------------------! |
---|
| 203 | zrhoco = rau0 * rn_cio |
---|
| 204 | |
---|
| 205 | ! ecc2: square of yield ellipse eccenticrity |
---|
| 206 | ecc2 = rn_ecc * rn_ecc |
---|
| 207 | z1_ecc2 = 1._wp / ecc2 |
---|
| 208 | |
---|
| 209 | ! Time step for subcycling |
---|
| 210 | zdtevp = rdt_ice / REAL( nn_nevp ) |
---|
| 211 | z1_dtevp = 1._wp / zdtevp |
---|
| 212 | |
---|
| 213 | ! alpha parameters (Bouillon 2009) |
---|
| 214 | zalph1 = ( 2._wp * rn_relast * rdt_ice ) * z1_dtevp |
---|
| 215 | zalph2 = zalph1 * z1_ecc2 |
---|
| 216 | |
---|
| 217 | ! alpha and beta parameters (Bouillon 2013) |
---|
| 218 | !!zalph1 = 40. |
---|
| 219 | !!zalph2 = 40. |
---|
| 220 | !!zbeta = 3000. |
---|
| 221 | !!zbeta = REAL( nn_nevp ) ! close to classical EVP of Hunke (2001) |
---|
| 222 | |
---|
| 223 | z1_alph1 = 1._wp / ( zalph1 + 1._wp ) |
---|
| 224 | z1_alph2 = 1._wp / ( zalph2 + 1._wp ) |
---|
| 225 | |
---|
| 226 | ! Initialise stress tensor |
---|
[7753] | 227 | zs1 (:,:) = stress1_i (:,:) |
---|
| 228 | zs2 (:,:) = stress2_i (:,:) |
---|
| 229 | zs12(:,:) = stress12_i(:,:) |
---|
[7646] | 230 | |
---|
| 231 | ! Ice strength |
---|
| 232 | CALL lim_itd_me_icestrength( nn_icestr ) |
---|
| 233 | |
---|
| 234 | ! scale factors |
---|
| 235 | DO jj = 2, jpjm1 |
---|
| 236 | DO ji = fs_2, fs_jpim1 |
---|
| 237 | z1_e1t0(ji,jj) = 1._wp / ( e1t(ji+1,jj ) + e1t(ji,jj ) ) |
---|
| 238 | z1_e2t0(ji,jj) = 1._wp / ( e2t(ji ,jj+1) + e2t(ji,jj ) ) |
---|
[825] | 239 | END DO |
---|
| 240 | END DO |
---|
[7646] | 241 | |
---|
[921] | 242 | ! |
---|
| 243 | !------------------------------------------------------------------------------! |
---|
| 244 | ! 2) Wind / ocean stress, mass terms, coriolis terms |
---|
| 245 | !------------------------------------------------------------------------------! |
---|
| 246 | |
---|
[3625] | 247 | IF( nn_ice_embd == 2 ) THEN !== embedded sea ice: compute representative ice top surface ==! |
---|
[5123] | 248 | ! |
---|
| 249 | ! average interpolation coeff as used in dynspg = (1/nn_fsbc) * {SUM[n/nn_fsbc], n=0,nn_fsbc-1} |
---|
| 250 | ! = (1/nn_fsbc)^2 * {SUM[n], n=0,nn_fsbc-1} |
---|
[3625] | 251 | zintn = REAL( nn_fsbc - 1 ) / REAL( nn_fsbc ) * 0.5_wp |
---|
[5123] | 252 | ! |
---|
| 253 | ! average interpolation coeff as used in dynspg = (1/nn_fsbc) * {SUM[1-n/nn_fsbc], n=0,nn_fsbc-1} |
---|
| 254 | ! = (1/nn_fsbc)^2 * (nn_fsbc^2 - {SUM[n], n=0,nn_fsbc-1}) |
---|
[3625] | 255 | zintb = REAL( nn_fsbc + 1 ) / REAL( nn_fsbc ) * 0.5_wp |
---|
[5123] | 256 | ! |
---|
[7753] | 257 | zpice(:,:) = ssh_m(:,:) + ( zintn * snwice_mass(:,:) + zintb * snwice_mass_b(:,:) ) * r1_rau0 |
---|
[5123] | 258 | ! |
---|
[3625] | 259 | ELSE !== non-embedded sea ice: use ocean surface for slope calculation ==! |
---|
[7753] | 260 | zpice(:,:) = ssh_m(:,:) |
---|
[3625] | 261 | ENDIF |
---|
| 262 | |
---|
[7646] | 263 | DO jj = 2, jpjm1 |
---|
[868] | 264 | DO ji = fs_2, fs_jpim1 |
---|
[825] | 265 | |
---|
[7646] | 266 | ! ice fraction at U-V points |
---|
| 267 | zaU(ji,jj) = 0.5_wp * ( at_i(ji,jj) * e1e2t(ji,jj) + at_i(ji+1,jj) * e1e2t(ji+1,jj) ) * r1_e1e2u(ji,jj) * umask(ji,jj,1) |
---|
| 268 | zaV(ji,jj) = 0.5_wp * ( at_i(ji,jj) * e1e2t(ji,jj) + at_i(ji,jj+1) * e1e2t(ji,jj+1) ) * r1_e1e2v(ji,jj) * vmask(ji,jj,1) |
---|
[4990] | 269 | |
---|
[7646] | 270 | ! Ice/snow mass at U-V points |
---|
| 271 | zm1 = ( rhosn * vt_s(ji ,jj ) + rhoic * vt_i(ji ,jj ) ) |
---|
| 272 | zm2 = ( rhosn * vt_s(ji+1,jj ) + rhoic * vt_i(ji+1,jj ) ) |
---|
| 273 | zm3 = ( rhosn * vt_s(ji ,jj+1) + rhoic * vt_i(ji ,jj+1) ) |
---|
| 274 | zmassU = 0.5_wp * ( zm1 * e1e2t(ji,jj) + zm2 * e1e2t(ji+1,jj) ) * r1_e1e2u(ji,jj) * umask(ji,jj,1) |
---|
| 275 | zmassV = 0.5_wp * ( zm1 * e1e2t(ji,jj) + zm3 * e1e2t(ji,jj+1) ) * r1_e1e2v(ji,jj) * vmask(ji,jj,1) |
---|
[825] | 276 | |
---|
[7646] | 277 | ! Ocean currents at U-V points |
---|
| 278 | v_oceU(ji,jj) = 0.5_wp * ( ( v_oce(ji ,jj) + v_oce(ji ,jj-1) ) * e1t(ji+1,jj) & |
---|
| 279 | & + ( v_oce(ji+1,jj) + v_oce(ji+1,jj-1) ) * e1t(ji ,jj) ) * z1_e1t0(ji,jj) * umask(ji,jj,1) |
---|
| 280 | |
---|
| 281 | u_oceV(ji,jj) = 0.5_wp * ( ( u_oce(ji,jj ) + u_oce(ji-1,jj ) ) * e2t(ji,jj+1) & |
---|
| 282 | & + ( u_oce(ji,jj+1) + u_oce(ji-1,jj+1) ) * e2t(ji,jj ) ) * z1_e2t0(ji,jj) * vmask(ji,jj,1) |
---|
[825] | 283 | |
---|
[7646] | 284 | ! Coriolis at T points (m*f) |
---|
| 285 | zmf(ji,jj) = zm1 * ff_t(ji,jj) |
---|
[825] | 286 | |
---|
[7646] | 287 | ! m/dt |
---|
| 288 | zmU_t(ji,jj) = zmassU * z1_dtevp |
---|
| 289 | zmV_t(ji,jj) = zmassV * z1_dtevp |
---|
[825] | 290 | |
---|
[7646] | 291 | ! Drag ice-atm. |
---|
| 292 | zTauU_ia(ji,jj) = zaU(ji,jj) * utau_ice(ji,jj) |
---|
| 293 | zTauV_ia(ji,jj) = zaV(ji,jj) * vtau_ice(ji,jj) |
---|
[825] | 294 | |
---|
[7646] | 295 | ! Surface pressure gradient (- m*g*GRAD(ssh)) at U-V points |
---|
| 296 | zspgU(ji,jj) = - zmassU * grav * ( zpice(ji+1,jj) - zpice(ji,jj) ) * r1_e1u(ji,jj) |
---|
| 297 | zspgV(ji,jj) = - zmassV * grav * ( zpice(ji,jj+1) - zpice(ji,jj) ) * r1_e2v(ji,jj) |
---|
[825] | 298 | |
---|
[7646] | 299 | ! masks |
---|
| 300 | zmaskU(ji,jj) = 1._wp - MAX( 0._wp, SIGN( 1._wp, -zmassU ) ) ! 0 if no ice |
---|
| 301 | zmaskV(ji,jj) = 1._wp - MAX( 0._wp, SIGN( 1._wp, -zmassV ) ) ! 0 if no ice |
---|
[834] | 302 | |
---|
[7646] | 303 | ! switches |
---|
| 304 | zswitchU(ji,jj) = MAX( 0._wp, SIGN( 1._wp, zmassU - zmmin ) ) ! 0 if ice mass < zmmin |
---|
| 305 | zswitchV(ji,jj) = MAX( 0._wp, SIGN( 1._wp, zmassV - zmmin ) ) ! 0 if ice mass < zmmin |
---|
[825] | 306 | |
---|
| 307 | END DO |
---|
| 308 | END DO |
---|
[7646] | 309 | CALL lbc_lnk( zmf, 'T', 1. ) |
---|
[921] | 310 | ! |
---|
| 311 | !------------------------------------------------------------------------------! |
---|
| 312 | ! 3) Solution of the momentum equation, iterative procedure |
---|
| 313 | !------------------------------------------------------------------------------! |
---|
| 314 | ! |
---|
[2528] | 315 | ! !----------------------! |
---|
[5123] | 316 | DO jter = 1 , nn_nevp ! loop over jter ! |
---|
[2528] | 317 | ! !----------------------! |
---|
[7646] | 318 | IF(ln_ctl) THEN ! Convergence test |
---|
| 319 | DO jj = 1, jpjm1 |
---|
[7753] | 320 | zu_ice(:,jj) = u_ice(:,jj) ! velocity at previous time step |
---|
| 321 | zv_ice(:,jj) = v_ice(:,jj) |
---|
[7646] | 322 | END DO |
---|
| 323 | ENDIF |
---|
[825] | 324 | |
---|
[7646] | 325 | ! --- divergence, tension & shear (Appendix B of Hunke & Dukowicz, 2002) --- ! |
---|
| 326 | DO jj = 1, jpjm1 ! loops start at 1 since there is no boundary condition (lbc_lnk) at i=1 and j=1 for F points |
---|
| 327 | DO ji = 1, jpim1 |
---|
[825] | 328 | |
---|
[7646] | 329 | ! shear at F points |
---|
[5123] | 330 | zds(ji,jj) = ( ( u_ice(ji,jj+1) * r1_e1u(ji,jj+1) - u_ice(ji,jj) * r1_e1u(ji,jj) ) * e1f(ji,jj) * e1f(ji,jj) & |
---|
| 331 | & + ( v_ice(ji+1,jj) * r1_e2v(ji+1,jj) - v_ice(ji,jj) * r1_e2v(ji,jj) ) * e2f(ji,jj) * e2f(ji,jj) & |
---|
[7646] | 332 | & ) * r1_e1e2f(ji,jj) * zfmask(ji,jj) |
---|
[825] | 333 | |
---|
[7646] | 334 | END DO |
---|
| 335 | END DO |
---|
| 336 | CALL lbc_lnk( zds, 'F', 1. ) |
---|
[825] | 337 | |
---|
[7646] | 338 | DO jj = 2, jpjm1 |
---|
| 339 | DO ji = 2, jpim1 ! no vector loop |
---|
[825] | 340 | |
---|
[7646] | 341 | ! shear**2 at T points (doc eq. A16) |
---|
| 342 | zds2 = ( zds(ji,jj ) * zds(ji,jj ) * e1e2f(ji,jj ) + zds(ji-1,jj ) * zds(ji-1,jj ) * e1e2f(ji-1,jj ) & |
---|
| 343 | & + zds(ji,jj-1) * zds(ji,jj-1) * e1e2f(ji,jj-1) + zds(ji-1,jj-1) * zds(ji-1,jj-1) * e1e2f(ji-1,jj-1) & |
---|
| 344 | & ) * 0.25_wp * r1_e1e2t(ji,jj) |
---|
| 345 | |
---|
| 346 | ! divergence at T points |
---|
| 347 | zdiv = ( e2u(ji,jj) * u_ice(ji,jj) - e2u(ji-1,jj) * u_ice(ji-1,jj) & |
---|
| 348 | & + e1v(ji,jj) * v_ice(ji,jj) - e1v(ji,jj-1) * v_ice(ji,jj-1) & |
---|
| 349 | & ) * r1_e1e2t(ji,jj) |
---|
| 350 | zdiv2 = zdiv * zdiv |
---|
| 351 | |
---|
| 352 | ! tension at T points |
---|
| 353 | zdt = ( ( u_ice(ji,jj) * r1_e2u(ji,jj) - u_ice(ji-1,jj) * r1_e2u(ji-1,jj) ) * e2t(ji,jj) * e2t(ji,jj) & |
---|
| 354 | & - ( v_ice(ji,jj) * r1_e1v(ji,jj) - v_ice(ji,jj-1) * r1_e1v(ji,jj-1) ) * e1t(ji,jj) * e1t(ji,jj) & |
---|
| 355 | & ) * r1_e1e2t(ji,jj) |
---|
| 356 | zdt2 = zdt * zdt |
---|
| 357 | |
---|
| 358 | ! delta at T points |
---|
| 359 | zdelta = SQRT( zdiv2 + ( zdt2 + zds2 ) * z1_ecc2 ) |
---|
| 360 | |
---|
| 361 | ! P/delta at T points |
---|
| 362 | zp_delt(ji,jj) = strength(ji,jj) / ( zdelta + rn_creepl ) |
---|
| 363 | |
---|
| 364 | ! stress at T points |
---|
| 365 | zs1(ji,jj) = ( zs1(ji,jj) * zalph1 + zp_delt(ji,jj) * ( zdiv - zdelta ) ) * z1_alph1 |
---|
| 366 | zs2(ji,jj) = ( zs2(ji,jj) * zalph2 + zp_delt(ji,jj) * ( zdt * z1_ecc2 ) ) * z1_alph2 |
---|
| 367 | |
---|
[921] | 368 | END DO |
---|
| 369 | END DO |
---|
[7646] | 370 | CALL lbc_lnk( zp_delt, 'T', 1. ) |
---|
[921] | 371 | |
---|
[7646] | 372 | DO jj = 1, jpjm1 |
---|
| 373 | DO ji = 1, jpim1 |
---|
[825] | 374 | |
---|
[7646] | 375 | ! P/delta at F points |
---|
| 376 | zp_delf = 0.25_wp * ( zp_delt(ji,jj) + zp_delt(ji+1,jj) + zp_delt(ji,jj+1) + zp_delt(ji+1,jj+1) ) |
---|
| 377 | |
---|
| 378 | ! stress at F points |
---|
| 379 | zs12(ji,jj)= ( zs12(ji,jj) * zalph2 + zp_delf * ( zds(ji,jj) * z1_ecc2 ) * 0.5_wp ) * z1_alph2 |
---|
[825] | 380 | |
---|
[7646] | 381 | END DO |
---|
| 382 | END DO |
---|
| 383 | CALL lbc_lnk_multi( zs1, 'T', 1., zs2, 'T', 1., zs12, 'F', 1. ) |
---|
| 384 | |
---|
[4205] | 385 | |
---|
[7646] | 386 | ! --- Ice internal stresses (Appendix C of Hunke and Dukowicz, 2002) --- ! |
---|
| 387 | DO jj = 2, jpjm1 |
---|
| 388 | DO ji = fs_2, fs_jpim1 |
---|
[825] | 389 | |
---|
[7646] | 390 | ! U points |
---|
| 391 | zfU(ji,jj) = 0.5_wp * ( ( zs1(ji+1,jj) - zs1(ji,jj) ) * e2u(ji,jj) & |
---|
| 392 | & + ( zs2(ji+1,jj) * e2t(ji+1,jj) * e2t(ji+1,jj) - zs2(ji,jj) * e2t(ji,jj) * e2t(ji,jj) & |
---|
| 393 | & ) * r1_e2u(ji,jj) & |
---|
| 394 | & + ( zs12(ji,jj) * e1f(ji,jj) * e1f(ji,jj) - zs12(ji,jj-1) * e1f(ji,jj-1) * e1f(ji,jj-1) & |
---|
| 395 | & ) * 2._wp * r1_e1u(ji,jj) & |
---|
| 396 | & ) * r1_e1e2u(ji,jj) |
---|
[825] | 397 | |
---|
[7646] | 398 | ! V points |
---|
| 399 | zfV(ji,jj) = 0.5_wp * ( ( zs1(ji,jj+1) - zs1(ji,jj) ) * e1v(ji,jj) & |
---|
| 400 | & - ( zs2(ji,jj+1) * e1t(ji,jj+1) * e1t(ji,jj+1) - zs2(ji,jj) * e1t(ji,jj) * e1t(ji,jj) & |
---|
| 401 | & ) * r1_e1v(ji,jj) & |
---|
| 402 | & + ( zs12(ji,jj) * e2f(ji,jj) * e2f(ji,jj) - zs12(ji-1,jj) * e2f(ji-1,jj) * e2f(ji-1,jj) & |
---|
| 403 | & ) * 2._wp * r1_e2v(ji,jj) & |
---|
| 404 | & ) * r1_e1e2v(ji,jj) |
---|
[825] | 405 | |
---|
[7646] | 406 | ! u_ice at V point |
---|
| 407 | u_iceV(ji,jj) = 0.5_wp * ( ( u_ice(ji,jj ) + u_ice(ji-1,jj ) ) * e2t(ji,jj+1) & |
---|
| 408 | & + ( u_ice(ji,jj+1) + u_ice(ji-1,jj+1) ) * e2t(ji,jj ) ) * z1_e2t0(ji,jj) * vmask(ji,jj,1) |
---|
| 409 | |
---|
| 410 | ! v_ice at U point |
---|
| 411 | v_iceU(ji,jj) = 0.5_wp * ( ( v_ice(ji ,jj) + v_ice(ji ,jj-1) ) * e1t(ji+1,jj) & |
---|
| 412 | & + ( v_ice(ji+1,jj) + v_ice(ji+1,jj-1) ) * e1t(ji ,jj) ) * z1_e1t0(ji,jj) * umask(ji,jj,1) |
---|
[4205] | 413 | |
---|
[5123] | 414 | END DO |
---|
| 415 | END DO |
---|
[825] | 416 | ! |
---|
[7646] | 417 | ! --- Computation of ice velocity --- ! |
---|
| 418 | ! Bouillon et al. 2013 (eq 47-48) => unstable unless alpha, beta are chosen wisely and large nn_nevp |
---|
| 419 | ! Bouillon et al. 2009 (eq 34-35) => stable |
---|
| 420 | IF( MOD(jter,2) .EQ. 0 ) THEN ! even iterations |
---|
| 421 | |
---|
| 422 | DO jj = 2, jpjm1 |
---|
[921] | 423 | DO ji = fs_2, fs_jpim1 |
---|
[825] | 424 | |
---|
[7646] | 425 | ! tau_io/(v_oce - v_ice) |
---|
| 426 | zTauO = zaV(ji,jj) * zrhoco * SQRT( ( v_ice (ji,jj) - v_oce (ji,jj) ) * ( v_ice (ji,jj) - v_oce (ji,jj) ) & |
---|
| 427 | & + ( u_iceV(ji,jj) - u_oceV(ji,jj) ) * ( u_iceV(ji,jj) - u_oceV(ji,jj) ) ) |
---|
| 428 | |
---|
| 429 | ! tau_bottom/v_ice |
---|
| 430 | zvel = MAX( zepsi, SQRT( v_ice(ji,jj) * v_ice(ji,jj) + u_iceV(ji,jj) * u_iceV(ji,jj) ) ) |
---|
| 431 | zTauB = - tau_icebfr(ji,jj) / zvel |
---|
| 432 | |
---|
| 433 | ! Coriolis at V-points (energy conserving formulation) |
---|
| 434 | zCor = - 0.25_wp * r1_e2v(ji,jj) * & |
---|
| 435 | & ( zmf(ji,jj ) * ( e2u(ji,jj ) * u_ice(ji,jj ) + e2u(ji-1,jj ) * u_ice(ji-1,jj ) ) & |
---|
| 436 | & + zmf(ji,jj+1) * ( e2u(ji,jj+1) * u_ice(ji,jj+1) + e2u(ji-1,jj+1) * u_ice(ji-1,jj+1) ) ) |
---|
| 437 | |
---|
| 438 | ! Sum of external forces (explicit solution) = F + tau_ia + Coriolis + spg + tau_io |
---|
| 439 | zTauE = zfV(ji,jj) + zTauV_ia(ji,jj) + zCor + zspgV(ji,jj) + zTauO * ( v_oce(ji,jj) - v_ice(ji,jj) ) |
---|
| 440 | |
---|
| 441 | ! landfast switch => 0 = static friction ; 1 = sliding friction |
---|
| 442 | rswitch = 1._wp - MIN( 1._wp, ABS( SIGN( 1._wp, ztauE - tau_icebfr(ji,jj) ) - SIGN( 1._wp, zTauE ) ) ) |
---|
| 443 | |
---|
| 444 | ! ice velocity using implicit formulation (cf Madec doc & Bouillon 2009) |
---|
| 445 | v_ice(ji,jj) = ( ( rswitch * ( zmV_t(ji,jj) * v_ice(ji,jj) & ! previous velocity |
---|
| 446 | & + zTauE + zTauO * v_ice(ji,jj) & ! F + tau_ia + Coriolis + spg + tau_io(only ocean part) |
---|
| 447 | & ) / MAX( zepsi, zmV_t(ji,jj) + zTauO - zTauB ) & ! m/dt + tau_io(only ice part) + landfast |
---|
| 448 | & + ( 1._wp - rswitch ) * v_ice(ji,jj) * MAX( 0._wp, 1._wp - zdtevp * rn_lfrelax ) & ! static friction => slow decrease to v=0 |
---|
| 449 | & ) * zswitchV(ji,jj) + v_oce(ji,jj) * ( 1._wp - zswitchV(ji,jj) ) & ! v_ice = v_oce if mass < zmmin |
---|
| 450 | & ) * zmaskV(ji,jj) |
---|
| 451 | ! Bouillon 2013 |
---|
| 452 | !!v_ice(ji,jj) = ( zmV_t(ji,jj) * ( zbeta * v_ice(ji,jj) + v_ice_b(ji,jj) ) & |
---|
| 453 | !! & + zfV(ji,jj) + zCor + zTauV_ia(ji,jj) + zTauO * v_oce(ji,jj) + zspgV(ji,jj) & |
---|
| 454 | !! & ) / MAX( zmV_t(ji,jj) * ( zbeta + 1._wp ) + zTauO - zTauB, zepsi ) * zswitchV(ji,jj) |
---|
| 455 | |
---|
[921] | 456 | END DO |
---|
| 457 | END DO |
---|
[7646] | 458 | CALL lbc_lnk( v_ice, 'V', -1. ) |
---|
| 459 | |
---|
| 460 | #if defined key_agrif |
---|
| 461 | !! CALL agrif_interp_lim3( 'V', jter, nn_nevp ) |
---|
| 462 | CALL agrif_interp_lim3( 'V' ) |
---|
[3680] | 463 | #endif |
---|
[7646] | 464 | IF( ln_bdy ) CALL bdy_ice_lim_dyn( 'V' ) |
---|
[825] | 465 | |
---|
[7646] | 466 | DO jj = 2, jpjm1 |
---|
[921] | 467 | DO ji = fs_2, fs_jpim1 |
---|
[7646] | 468 | |
---|
| 469 | ! tau_io/(u_oce - u_ice) |
---|
| 470 | zTauO = zaU(ji,jj) * zrhoco * SQRT( ( u_ice (ji,jj) - u_oce (ji,jj) ) * ( u_ice (ji,jj) - u_oce (ji,jj) ) & |
---|
| 471 | & + ( v_iceU(ji,jj) - v_oceU(ji,jj) ) * ( v_iceU(ji,jj) - v_oceU(ji,jj) ) ) |
---|
[834] | 472 | |
---|
[7646] | 473 | ! tau_bottom/u_ice |
---|
| 474 | zvel = MAX( zepsi, SQRT( v_iceU(ji,jj) * v_iceU(ji,jj) + u_ice(ji,jj) * u_ice(ji,jj) ) ) |
---|
| 475 | zTauB = - tau_icebfr(ji,jj) / zvel |
---|
| 476 | |
---|
| 477 | ! Coriolis at U-points (energy conserving formulation) |
---|
| 478 | zCor = 0.25_wp * r1_e1u(ji,jj) * & |
---|
| 479 | & ( zmf(ji ,jj) * ( e1v(ji ,jj) * v_ice(ji ,jj) + e1v(ji ,jj-1) * v_ice(ji ,jj-1) ) & |
---|
| 480 | & + zmf(ji+1,jj) * ( e1v(ji+1,jj) * v_ice(ji+1,jj) + e1v(ji+1,jj-1) * v_ice(ji+1,jj-1) ) ) |
---|
| 481 | |
---|
| 482 | ! Sum of external forces (explicit solution) = F + tau_ia + Coriolis + spg + tau_io |
---|
| 483 | zTauE = zfU(ji,jj) + zTauU_ia(ji,jj) + zCor + zspgU(ji,jj) + zTauO * ( u_oce(ji,jj) - u_ice(ji,jj) ) |
---|
| 484 | |
---|
| 485 | ! landfast switch => 0 = static friction ; 1 = sliding friction |
---|
| 486 | rswitch = 1._wp - MIN( 1._wp, ABS( SIGN( 1._wp, ztauE - tau_icebfr(ji,jj) ) - SIGN( 1._wp, zTauE ) ) ) |
---|
| 487 | |
---|
| 488 | ! ice velocity using implicit formulation (cf Madec doc & Bouillon 2009) |
---|
| 489 | u_ice(ji,jj) = ( ( rswitch * ( zmU_t(ji,jj) * u_ice(ji,jj) & ! previous velocity |
---|
| 490 | & + zTauE + zTauO * u_ice(ji,jj) & ! F + tau_ia + Coriolis + spg + tau_io(only ocean part) |
---|
| 491 | & ) / MAX( zepsi, zmU_t(ji,jj) + zTauO - zTauB ) & ! m/dt + tau_io(only ice part) + landfast |
---|
| 492 | & + ( 1._wp - rswitch ) * u_ice(ji,jj) * MAX( 0._wp, 1._wp - zdtevp * rn_lfrelax ) & ! static friction => slow decrease to v=0 |
---|
| 493 | & ) * zswitchU(ji,jj) + u_oce(ji,jj) * ( 1._wp - zswitchU(ji,jj) ) & ! v_ice = v_oce if mass < zmmin |
---|
| 494 | & ) * zmaskU(ji,jj) |
---|
| 495 | ! Bouillon 2013 |
---|
| 496 | !!u_ice(ji,jj) = ( zmU_t(ji,jj) * ( zbeta * u_ice(ji,jj) + u_ice_b(ji,jj) ) & |
---|
| 497 | !! & + zfU(ji,jj) + zCor + zTauU_ia(ji,jj) + zTauO * u_oce(ji,jj) + zspgU(ji,jj) & |
---|
| 498 | !! & ) / MAX( zmU_t(ji,jj) * ( zbeta + 1._wp ) + zTauO - zTauB, zepsi ) * zswitchU(ji,jj) |
---|
[921] | 499 | END DO |
---|
| 500 | END DO |
---|
[7646] | 501 | CALL lbc_lnk( u_ice, 'U', -1. ) |
---|
| 502 | |
---|
| 503 | #if defined key_agrif |
---|
| 504 | !! CALL agrif_interp_lim3( 'U', jter, nn_nevp ) |
---|
| 505 | CALL agrif_interp_lim3( 'U' ) |
---|
[3680] | 506 | #endif |
---|
[7646] | 507 | IF( ln_bdy ) CALL bdy_ice_lim_dyn( 'U' ) |
---|
[825] | 508 | |
---|
[7646] | 509 | ELSE ! odd iterations |
---|
| 510 | |
---|
| 511 | DO jj = 2, jpjm1 |
---|
[921] | 512 | DO ji = fs_2, fs_jpim1 |
---|
[825] | 513 | |
---|
[7646] | 514 | ! tau_io/(u_oce - u_ice) |
---|
| 515 | zTauO = zaU(ji,jj) * zrhoco * SQRT( ( u_ice (ji,jj) - u_oce (ji,jj) ) * ( u_ice (ji,jj) - u_oce (ji,jj) ) & |
---|
| 516 | & + ( v_iceU(ji,jj) - v_oceU(ji,jj) ) * ( v_iceU(ji,jj) - v_oceU(ji,jj) ) ) |
---|
| 517 | |
---|
| 518 | ! tau_bottom/u_ice |
---|
| 519 | zvel = MAX( zepsi, SQRT( v_iceU(ji,jj) * v_iceU(ji,jj) + u_ice(ji,jj) * u_ice(ji,jj) ) ) |
---|
| 520 | zTauB = - tau_icebfr(ji,jj) / zvel |
---|
| 521 | |
---|
| 522 | ! Coriolis at U-points (energy conserving formulation) |
---|
| 523 | zCor = 0.25_wp * r1_e1u(ji,jj) * & |
---|
| 524 | & ( zmf(ji ,jj) * ( e1v(ji ,jj) * v_ice(ji ,jj) + e1v(ji ,jj-1) * v_ice(ji ,jj-1) ) & |
---|
| 525 | & + zmf(ji+1,jj) * ( e1v(ji+1,jj) * v_ice(ji+1,jj) + e1v(ji+1,jj-1) * v_ice(ji+1,jj-1) ) ) |
---|
| 526 | |
---|
| 527 | ! Sum of external forces (explicit solution) = F + tau_ia + Coriolis + spg + tau_io |
---|
| 528 | zTauE = zfU(ji,jj) + zTauU_ia(ji,jj) + zCor + zspgU(ji,jj) + zTauO * ( u_oce(ji,jj) - u_ice(ji,jj) ) |
---|
| 529 | |
---|
| 530 | ! landfast switch => 0 = static friction ; 1 = sliding friction |
---|
| 531 | rswitch = 1._wp - MIN( 1._wp, ABS( SIGN( 1._wp, ztauE - tau_icebfr(ji,jj) ) - SIGN( 1._wp, zTauE ) ) ) |
---|
| 532 | |
---|
| 533 | ! ice velocity using implicit formulation (cf Madec doc & Bouillon 2009) |
---|
| 534 | u_ice(ji,jj) = ( ( rswitch * ( zmU_t(ji,jj) * u_ice(ji,jj) & ! previous velocity |
---|
| 535 | & + zTauE + zTauO * u_ice(ji,jj) & ! F + tau_ia + Coriolis + spg + tau_io(only ocean part) |
---|
| 536 | & ) / MAX( zepsi, zmU_t(ji,jj) + zTauO - zTauB ) & ! m/dt + tau_io(only ice part) + landfast |
---|
| 537 | & + ( 1._wp - rswitch ) * u_ice(ji,jj) * MAX( 0._wp, 1._wp - zdtevp * rn_lfrelax ) & ! static friction => slow decrease to v=0 |
---|
| 538 | & ) * zswitchU(ji,jj) + u_oce(ji,jj) * ( 1._wp - zswitchU(ji,jj) ) & ! v_ice = v_oce if mass < zmmin |
---|
| 539 | & ) * zmaskU(ji,jj) |
---|
| 540 | ! Bouillon 2013 |
---|
| 541 | !!u_ice(ji,jj) = ( zmU_t(ji,jj) * ( zbeta * u_ice(ji,jj) + u_ice_b(ji,jj) ) & |
---|
| 542 | !! & + zfU(ji,jj) + zCor + zTauU_ia(ji,jj) + zTauO * u_oce(ji,jj) + zspgU(ji,jj) & |
---|
| 543 | !! & ) / MAX( zmU_t(ji,jj) * ( zbeta + 1._wp ) + zTauO - zTauB, zepsi ) * zswitchU(ji,jj) |
---|
[921] | 544 | END DO |
---|
| 545 | END DO |
---|
[7646] | 546 | CALL lbc_lnk( u_ice, 'U', -1. ) |
---|
| 547 | |
---|
| 548 | #if defined key_agrif |
---|
| 549 | !! CALL agrif_interp_lim3( 'U', jter, nn_nevp ) |
---|
| 550 | CALL agrif_interp_lim3( 'U' ) |
---|
[3680] | 551 | #endif |
---|
[7646] | 552 | IF( ln_bdy ) CALL bdy_ice_lim_dyn( 'U' ) |
---|
[825] | 553 | |
---|
[7646] | 554 | DO jj = 2, jpjm1 |
---|
[921] | 555 | DO ji = fs_2, fs_jpim1 |
---|
[7646] | 556 | |
---|
| 557 | ! tau_io/(v_oce - v_ice) |
---|
| 558 | zTauO = zaV(ji,jj) * zrhoco * SQRT( ( v_ice (ji,jj) - v_oce (ji,jj) ) * ( v_ice (ji,jj) - v_oce (ji,jj) ) & |
---|
| 559 | & + ( u_iceV(ji,jj) - u_oceV(ji,jj) ) * ( u_iceV(ji,jj) - u_oceV(ji,jj) ) ) |
---|
[825] | 560 | |
---|
[7646] | 561 | ! tau_bottom/v_ice |
---|
| 562 | zvel = MAX( zepsi, SQRT( v_ice(ji,jj) * v_ice(ji,jj) + u_iceV(ji,jj) * u_iceV(ji,jj) ) ) |
---|
| 563 | ztauB = - tau_icebfr(ji,jj) / zvel |
---|
| 564 | |
---|
| 565 | ! Coriolis at V-points (energy conserving formulation) |
---|
| 566 | zCor = - 0.25_wp * r1_e2v(ji,jj) * & |
---|
| 567 | & ( zmf(ji,jj ) * ( e2u(ji,jj ) * u_ice(ji,jj ) + e2u(ji-1,jj ) * u_ice(ji-1,jj ) ) & |
---|
| 568 | & + zmf(ji,jj+1) * ( e2u(ji,jj+1) * u_ice(ji,jj+1) + e2u(ji-1,jj+1) * u_ice(ji-1,jj+1) ) ) |
---|
| 569 | |
---|
| 570 | ! Sum of external forces (explicit solution) = F + tau_ia + Coriolis + spg + tau_io |
---|
| 571 | zTauE = zfV(ji,jj) + zTauV_ia(ji,jj) + zCor + zspgV(ji,jj) + zTauO * ( v_oce(ji,jj) - v_ice(ji,jj) ) |
---|
| 572 | |
---|
| 573 | ! landfast switch => 0 = static friction (tau_icebfr > zTauE); 1 = sliding friction |
---|
| 574 | rswitch = 1._wp - MIN( 1._wp, ABS( SIGN( 1._wp, zTauE - tau_icebfr(ji,jj) ) - SIGN( 1._wp, zTauE ) ) ) |
---|
| 575 | |
---|
| 576 | ! ice velocity using implicit formulation (cf Madec doc & Bouillon 2009) |
---|
| 577 | v_ice(ji,jj) = ( ( rswitch * ( zmV_t(ji,jj) * v_ice(ji,jj) & ! previous velocity |
---|
| 578 | & + zTauE + zTauO * v_ice(ji,jj) & ! F + tau_ia + Coriolis + spg + tau_io(only ocean part) |
---|
| 579 | & ) / MAX( zepsi, zmV_t(ji,jj) + zTauO - zTauB ) & ! m/dt + tau_io(only ice part) + landfast |
---|
| 580 | & + ( 1._wp - rswitch ) * v_ice(ji,jj) * MAX( 0._wp, 1._wp - zdtevp * rn_lfrelax ) & ! static friction => slow decrease to v=0 |
---|
| 581 | & ) * zswitchV(ji,jj) + v_oce(ji,jj) * ( 1._wp - zswitchV(ji,jj) ) & ! v_ice = v_oce if mass < zmmin |
---|
| 582 | & ) * zmaskV(ji,jj) |
---|
| 583 | ! Bouillon 2013 |
---|
| 584 | !!v_ice(ji,jj) = ( zmV_t(ji,jj) * ( zbeta * v_ice(ji,jj) + v_ice_b(ji,jj) ) & |
---|
| 585 | !! & + zfV(ji,jj) + zCor + zTauV_ia(ji,jj) + zTauO * v_oce(ji,jj) + zspgV(ji,jj) & |
---|
| 586 | !! & ) / MAX( zmV_t(ji,jj) * ( zbeta + 1._wp ) + zTauO - zTauB, zepsi ) * zswitchV(ji,jj) |
---|
[5123] | 587 | END DO |
---|
| 588 | END DO |
---|
[7646] | 589 | CALL lbc_lnk( v_ice, 'V', -1. ) |
---|
| 590 | |
---|
| 591 | #if defined key_agrif |
---|
| 592 | !! CALL agrif_interp_lim3( 'V', jter, nn_nevp ) |
---|
| 593 | CALL agrif_interp_lim3( 'V' ) |
---|
[3680] | 594 | #endif |
---|
[7646] | 595 | IF( ln_bdy ) CALL bdy_ice_lim_dyn( 'V' ) |
---|
[825] | 596 | |
---|
[921] | 597 | ENDIF |
---|
[4161] | 598 | |
---|
[7646] | 599 | IF(ln_ctl) THEN ! Convergence test |
---|
| 600 | DO jj = 2 , jpjm1 |
---|
[7753] | 601 | zresr(:,jj) = MAX( ABS( u_ice(:,jj) - zu_ice(:,jj) ), ABS( v_ice(:,jj) - zv_ice(:,jj) ) ) |
---|
[921] | 602 | END DO |
---|
[7646] | 603 | zresm = MAXVAL( zresr( 1:jpi, 2:jpjm1 ) ) |
---|
[921] | 604 | IF( lk_mpp ) CALL mpp_max( zresm ) ! max over the global domain |
---|
| 605 | ENDIF |
---|
[7646] | 606 | ! |
---|
[4161] | 607 | ! ! ==================== ! |
---|
[868] | 608 | END DO ! end loop over jter ! |
---|
[825] | 609 | ! ! ==================== ! |
---|
[921] | 610 | ! |
---|
| 611 | !------------------------------------------------------------------------------! |
---|
[7646] | 612 | ! 4) Recompute delta, shear and div (inputs for mechanical redistribution) |
---|
[921] | 613 | !------------------------------------------------------------------------------! |
---|
[7646] | 614 | DO jj = 1, jpjm1 |
---|
| 615 | DO ji = 1, jpim1 |
---|
[866] | 616 | |
---|
[7646] | 617 | ! shear at F points |
---|
| 618 | zds(ji,jj) = ( ( u_ice(ji,jj+1) * r1_e1u(ji,jj+1) - u_ice(ji,jj) * r1_e1u(ji,jj) ) * e1f(ji,jj) * e1f(ji,jj) & |
---|
| 619 | & + ( v_ice(ji+1,jj) * r1_e2v(ji+1,jj) - v_ice(ji,jj) * r1_e2v(ji,jj) ) * e2f(ji,jj) * e2f(ji,jj) & |
---|
| 620 | & ) * r1_e1e2f(ji,jj) * zfmask(ji,jj) |
---|
[5429] | 621 | |
---|
[868] | 622 | END DO |
---|
[7646] | 623 | END DO |
---|
| 624 | CALL lbc_lnk( zds, 'F', 1. ) |
---|
| 625 | |
---|
| 626 | DO jj = 2, jpjm1 |
---|
| 627 | DO ji = 2, jpim1 ! no vector loop |
---|
| 628 | |
---|
| 629 | ! tension**2 at T points |
---|
| 630 | zdt = ( ( u_ice(ji,jj) * r1_e2u(ji,jj) - u_ice(ji-1,jj) * r1_e2u(ji-1,jj) ) * e2t(ji,jj) * e2t(ji,jj) & |
---|
| 631 | & - ( v_ice(ji,jj) * r1_e1v(ji,jj) - v_ice(ji,jj-1) * r1_e1v(ji,jj-1) ) * e1t(ji,jj) * e1t(ji,jj) & |
---|
| 632 | & ) * r1_e1e2t(ji,jj) |
---|
| 633 | zdt2 = zdt * zdt |
---|
| 634 | |
---|
| 635 | ! shear**2 at T points (doc eq. A16) |
---|
| 636 | zds2 = ( zds(ji,jj ) * zds(ji,jj ) * e1e2f(ji,jj ) + zds(ji-1,jj ) * zds(ji-1,jj ) * e1e2f(ji-1,jj ) & |
---|
| 637 | & + zds(ji,jj-1) * zds(ji,jj-1) * e1e2f(ji,jj-1) + zds(ji-1,jj-1) * zds(ji-1,jj-1) * e1e2f(ji-1,jj-1) & |
---|
| 638 | & ) * 0.25_wp * r1_e1e2t(ji,jj) |
---|
| 639 | |
---|
| 640 | ! shear at T points |
---|
| 641 | shear_i(ji,jj) = SQRT( zdt2 + zds2 ) |
---|
[868] | 642 | |
---|
[7646] | 643 | ! divergence at T points |
---|
| 644 | divu_i(ji,jj) = ( e2u(ji,jj) * u_ice(ji,jj) - e2u(ji-1,jj) * u_ice(ji-1,jj) & |
---|
| 645 | & + e1v(ji,jj) * v_ice(ji,jj) - e1v(ji,jj-1) * v_ice(ji,jj-1) & |
---|
| 646 | & ) * r1_e1e2t(ji,jj) |
---|
| 647 | |
---|
| 648 | ! delta at T points |
---|
| 649 | zdelta = SQRT( divu_i(ji,jj) * divu_i(ji,jj) + ( zdt2 + zds2 ) * z1_ecc2 ) |
---|
| 650 | rswitch = 1._wp - MAX( 0._wp, SIGN( 1._wp, -zdelta ) ) ! 0 if delta=0 |
---|
| 651 | delta_i(ji,jj) = zdelta + rn_creepl * rswitch |
---|
[868] | 652 | |
---|
[5123] | 653 | END DO |
---|
| 654 | END DO |
---|
[7646] | 655 | CALL lbc_lnk_multi( shear_i, 'T', 1., divu_i, 'T', 1., delta_i, 'T', 1. ) |
---|
| 656 | |
---|
| 657 | ! --- Store the stress tensor for the next time step --- ! |
---|
[7753] | 658 | stress1_i (:,:) = zs1 (:,:) |
---|
| 659 | stress2_i (:,:) = zs2 (:,:) |
---|
| 660 | stress12_i(:,:) = zs12(:,:) |
---|
[7646] | 661 | ! |
---|
[868] | 662 | |
---|
[921] | 663 | !------------------------------------------------------------------------------! |
---|
[7646] | 664 | ! 5) Control prints of residual and charge ellipse |
---|
[921] | 665 | !------------------------------------------------------------------------------! |
---|
| 666 | ! |
---|
[834] | 667 | ! print the residual for convergence |
---|
| 668 | IF(ln_ctl) THEN |
---|
[868] | 669 | WRITE(charout,FMT="('lim_rhg : res =',D23.16, ' iter =',I4)") zresm, jter |
---|
[834] | 670 | CALL prt_ctl_info(charout) |
---|
| 671 | CALL prt_ctl(tab2d_1=u_ice, clinfo1=' lim_rhg : u_ice :', tab2d_2=v_ice, clinfo2=' v_ice :') |
---|
| 672 | ENDIF |
---|
[825] | 673 | |
---|
[834] | 674 | ! print charge ellipse |
---|
| 675 | ! This can be desactivated once the user is sure that the stress state |
---|
| 676 | ! lie on the charge ellipse. See Bouillon et al. 08 for more details |
---|
[825] | 677 | IF(ln_ctl) THEN |
---|
| 678 | CALL prt_ctl_info('lim_rhg : numit :',ivar1=numit) |
---|
| 679 | CALL prt_ctl_info('lim_rhg : nwrite :',ivar1=nwrite) |
---|
| 680 | CALL prt_ctl_info('lim_rhg : MOD :',ivar1=MOD(numit,nwrite)) |
---|
| 681 | IF( MOD(numit,nwrite) .EQ. 0 ) THEN |
---|
| 682 | WRITE(charout,FMT="('lim_rhg :', I4, I6, I1, I1, A10)") 1000, numit, 0, 0, ' ch. ell. ' |
---|
| 683 | CALL prt_ctl_info(charout) |
---|
[7646] | 684 | DO jj = 2, jpjm1 |
---|
[825] | 685 | DO ji = 2, jpim1 |
---|
[7646] | 686 | IF (strength(ji,jj) > 1.0) THEN |
---|
| 687 | zsig1 = ( zs1(ji,jj) + SQRT(zs2(ji,jj)**2 + 4*zs12(ji,jj)**2 ) ) / ( 2*strength(ji,jj) ) |
---|
| 688 | zsig2 = ( zs1(ji,jj) - SQRT(zs2(ji,jj)**2 + 4*zs12(ji,jj)**2 ) ) / ( 2*strength(ji,jj) ) |
---|
[825] | 689 | WRITE(charout,FMT="('lim_rhg :', I4, I4, D23.16, D23.16, D23.16, D23.16, A10)") |
---|
| 690 | CALL prt_ctl_info(charout) |
---|
| 691 | ENDIF |
---|
| 692 | END DO |
---|
| 693 | END DO |
---|
| 694 | WRITE(charout,FMT="('lim_rhg :', I4, I6, I1, I1, A10)") 2000, numit, 0, 0, ' ch. ell. ' |
---|
| 695 | CALL prt_ctl_info(charout) |
---|
| 696 | ENDIF |
---|
| 697 | ENDIF |
---|
[7646] | 698 | ! |
---|
| 699 | |
---|
| 700 | CALL wrk_dealloc( jpi,jpj, z1_e1t0, z1_e2t0, zp_delt ) |
---|
| 701 | CALL wrk_dealloc( jpi,jpj, zaU, zaV, zmU_t, zmV_t, zmf, zTauU_ia, ztauV_ia ) |
---|
| 702 | CALL wrk_dealloc( jpi,jpj, zspgU, zspgV, v_oceU, u_oceV, v_iceU, u_iceV, zfU, zfV ) |
---|
| 703 | CALL wrk_dealloc( jpi,jpj, zds, zs1, zs2, zs12, zu_ice, zv_ice, zresr, zpice ) |
---|
| 704 | CALL wrk_dealloc( jpi,jpj, zswitchU, zswitchV, zmaskU, zmaskV, zfmask, zwf ) |
---|
[3294] | 705 | |
---|
[825] | 706 | END SUBROUTINE lim_rhg |
---|
| 707 | |
---|
| 708 | #else |
---|
| 709 | !!---------------------------------------------------------------------- |
---|
| 710 | !! Default option Dummy module NO LIM sea-ice model |
---|
| 711 | !!---------------------------------------------------------------------- |
---|
| 712 | CONTAINS |
---|
[7646] | 713 | SUBROUTINE lim_rhg ! Dummy routine |
---|
| 714 | WRITE(*,*) 'lim_rhg: You should not have seen this print! error?' |
---|
[825] | 715 | END SUBROUTINE lim_rhg |
---|
| 716 | #endif |
---|
| 717 | |
---|
| 718 | !!============================================================================== |
---|
| 719 | END MODULE limrhg |
---|