| 1 | MODULE limsbc_2 |
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| 2 | !!====================================================================== |
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| 3 | !! *** MODULE limsbc_2 *** |
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| 4 | !! LIM-2 : updates the fluxes at the ocean surface with ice-ocean fluxes |
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| 5 | !!====================================================================== |
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| 6 | !! History : LIM ! 2000-01 (H. Goosse) Original code |
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| 7 | !! 1.0 ! 2002-07 (C. Ethe, G. Madec) re-writing F90 |
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| 8 | !! 3.0 ! 2006-07 (G. Madec) surface module |
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| 9 | !! 3.3 ! 2009-05 (G. Garric, C. Bricaud) addition of the lim2_evp case |
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| 10 | !! - ! 2010-11 (G. Madec) ice-ocean stress computed at each ocean time-step |
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| 11 | !!---------------------------------------------------------------------- |
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| 12 | #if defined key_lim2 |
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| 13 | !!---------------------------------------------------------------------- |
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| 14 | !! 'key_lim2' LIM 2.0 sea-ice model |
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| 15 | !!---------------------------------------------------------------------- |
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| 16 | !! lim_sbc_flx_2 : update mass, heat and salt fluxes at the ocean surface |
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| 17 | !! lim_sbc_tau_2 : update i- and j-stresses, and its modulus at the ocean surface |
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| 18 | !!---------------------------------------------------------------------- |
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| 19 | USE par_oce ! ocean parameters |
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| 20 | USE phycst ! physical constants |
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| 21 | USE dom_oce ! ocean domain |
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| 22 | USE dom_ice_2 ! LIM-2: ice domain |
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| 23 | USE ice_2 ! LIM-2: ice variables |
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| 24 | USE sbc_ice ! surface boundary condition: ice |
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| 25 | USE sbc_oce ! surface boundary condition: ocean |
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| 26 | |
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| 27 | USE lbclnk ! ocean lateral boundary condition - MPP exchanges |
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| 28 | USE in_out_manager ! I/O manager |
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| 29 | USE diaar5, ONLY : lk_diaar5 |
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| 30 | USE iom ! I/O library |
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| 31 | USE albedo ! albedo parameters |
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| 32 | USE prtctl ! Print control |
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| 33 | USE cpl_oasis3, ONLY : lk_cpl |
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| 34 | |
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| 35 | IMPLICIT NONE |
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| 36 | PRIVATE |
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| 37 | |
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| 38 | PUBLIC lim_sbc_flx_2 ! called by sbc_ice_lim_2 |
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| 39 | PUBLIC lim_sbc_tau_2 ! called by sbc_ice_lim_2 |
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| 40 | |
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| 41 | REAL(wp) :: r1_rdtice ! = 1. / rdt_ice |
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| 42 | REAL(wp) :: epsi16 = 1.e-16_wp ! constant values |
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| 43 | REAL(wp) :: rzero = 0._wp ! - - |
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| 44 | REAL(wp) :: rone = 1._wp ! - - |
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| 45 | ! |
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| 46 | REAL(wp), DIMENSION(jpi,jpj) :: soce_0, sice_0 ! constant SSS and ice salinity used in levitating sea-ice case |
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| 47 | |
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| 48 | REAL(wp), DIMENSION(jpi,jpj) :: utau_oce, vtau_oce ! air-ocean surface i- & j-stress [N/m2] |
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| 49 | REAL(wp), DIMENSION(jpi,jpj) :: tmod_io ! modulus of the ice-ocean relative velocity [m/s] |
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| 50 | |
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| 51 | !! * Substitutions |
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| 52 | # include "vectopt_loop_substitute.h90" |
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| 53 | !!---------------------------------------------------------------------- |
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| 54 | !! NEMO/LIM2 3.3 , UCL - NEMO Consortium (2010) |
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| 55 | !! $Id$ |
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| 56 | !! Software governed by the CeCILL licence (NEMOGCM/NEMO_CeCILL.txt) |
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| 57 | !!---------------------------------------------------------------------- |
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| 58 | CONTAINS |
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| 59 | |
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| 60 | SUBROUTINE lim_sbc_flx_2( kt ) |
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| 61 | !!------------------------------------------------------------------- |
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| 62 | !! *** ROUTINE lim_sbc_2 *** |
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| 63 | !! |
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| 64 | !! ** Purpose : Update surface ocean boundary condition over areas |
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| 65 | !! that are at least partially covered by sea-ice |
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| 66 | !! |
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| 67 | !! ** Action : - comput. of the momentum, heat and freshwater/salt |
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| 68 | !! fluxes at the ice-ocean interface. |
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| 69 | !! - Update |
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| 70 | !! |
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| 71 | !! ** Outputs : - qsr : sea heat flux: solar |
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| 72 | !! - qns : sea heat flux: non solar |
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| 73 | !! - emp : freshwater budget: volume flux |
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| 74 | !! - emps : freshwater budget: concentration/dillution |
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| 75 | !! - utau : sea surface i-stress (ocean referential) |
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| 76 | !! - vtau : sea surface j-stress (ocean referential) |
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| 77 | !! - fr_i : ice fraction |
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| 78 | !! - tn_ice : sea-ice surface temperature |
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| 79 | !! - alb_ice : sea-ice alberdo (lk_cpl=T) |
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| 80 | !! |
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| 81 | !! References : Goosse, H. et al. 1996, Bul. Soc. Roy. Sc. Liege, 65, 87-90. |
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| 82 | !! Tartinville et al. 2001 Ocean Modelling, 3, 95-108. |
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| 83 | !!--------------------------------------------------------------------- |
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| 84 | INTEGER, INTENT(in) :: kt ! number of iteration |
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| 85 | !! |
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| 86 | INTEGER :: ji, jj ! dummy loop indices |
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| 87 | INTEGER :: ii0, ii1, ij0, ij1 ! local integers |
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| 88 | INTEGER :: ifvt, i1mfr, idfr, iflt ! - - |
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| 89 | INTEGER :: ial, iadv, ifral, ifrdv ! - - |
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| 90 | REAL(wp) :: zqsr, zqns, zfm ! local scalars |
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| 91 | REAL(wp) :: zinda, zfons, zemp ! - - |
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| 92 | REAL(wp), DIMENSION(jpi,jpj) :: zqnsoce ! 2D workspace |
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| 93 | REAL(wp), DIMENSION(jpi,jpj,1) :: zalb, zalbp ! 2D/3D workspace |
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| 94 | !!--------------------------------------------------------------------- |
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| 95 | |
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| 96 | IF( kt == nit000 ) THEN |
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| 97 | IF(lwp) WRITE(numout,*) |
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| 98 | IF(lwp) WRITE(numout,*) 'lim_sbc_flx_2 : LIM-2 sea-ice - surface boundary condition - Mass, heat & salt fluxes' |
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| 99 | IF(lwp) WRITE(numout,*) '~~~~~~~~~~~~~ ' |
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| 100 | ! |
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| 101 | r1_rdtice = 1. / rdt_ice |
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| 102 | ! |
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| 103 | soce_0(:,:) = soce ! constant SSS and ice salinity used in levitating sea-ice case |
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| 104 | sice_0(:,:) = sice |
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| 105 | ! |
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| 106 | IF( cp_cfg == "orca" ) THEN ! decrease ocean & ice reference salinities in the Baltic sea |
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| 107 | WHERE( 14._wp <= glamt(:,:) .AND. glamt(:,:) <= 32._wp .AND. & |
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| 108 | & 54._wp <= gphit(:,:) .AND. gphit(:,:) <= 66._wp ) |
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| 109 | soce_0(:,:) = 4._wp |
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| 110 | sice_0(:,:) = 2._wp |
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| 111 | END WHERE |
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| 112 | ENDIF |
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| 113 | ! |
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| 114 | ENDIF |
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| 115 | |
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| 116 | !------------------------------------------! |
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| 117 | ! heat flux at the ocean surface ! |
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| 118 | !------------------------------------------! |
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| 119 | |
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| 120 | zqnsoce(:,:) = qns(:,:) |
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| 121 | DO jj = 1, jpj |
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| 122 | DO ji = 1, jpi |
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| 123 | zinda = 1.0 - MAX( rzero , SIGN( rone, - ( 1.0 - pfrld(ji,jj) ) ) ) |
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| 124 | ifvt = zinda * MAX( rzero , SIGN( rone, - phicif(ji,jj) ) ) |
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| 125 | i1mfr = 1.0 - MAX( rzero , SIGN( rone, - ( 1.0 - frld(ji,jj) ) ) ) |
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| 126 | idfr = 1.0 - MAX( rzero , SIGN( rone, frld(ji,jj) - pfrld(ji,jj) ) ) |
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| 127 | iflt = zinda * (1 - i1mfr) * (1 - ifvt ) |
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| 128 | ial = ifvt * i1mfr + ( 1 - ifvt ) * idfr |
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| 129 | iadv = ( 1 - i1mfr ) * zinda |
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| 130 | ifral = ( 1 - i1mfr * ( 1 - ial ) ) |
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| 131 | ifrdv = ( 1 - ifral * ( 1 - ial ) ) * iadv |
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| 132 | |
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| 133 | !!$ zinda = 1.0 - AINT( pfrld(ji,jj) ) ! = 0. if pure ocean else 1. (at previous time) |
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| 134 | !!$ |
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| 135 | !!$ i1mfr = 1.0 - AINT( frld(ji,jj) ) ! = 0. if pure ocean else 1. (at current time) |
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| 136 | !!$ |
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| 137 | !!$ IF( phicif(ji,jj) <= 0. ) THEN ; ifvt = zinda ! = 1. if (snow and no ice at previous time) else 0. ??? |
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| 138 | !!$ ELSE ; ifvt = 0. |
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| 139 | !!$ ENDIF |
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| 140 | !!$ |
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| 141 | !!$ IF( frld(ji,jj) >= pfrld(ji,jj) ) THEN ; idfr = 0. ! = 0. if lead fraction increases from previous to current |
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| 142 | !!$ ELSE ; idfr = 1. |
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| 143 | !!$ ENDIF |
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| 144 | !!$ |
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| 145 | !!$ iflt = zinda * (1 - i1mfr) * (1 - ifvt ) ! = 1. if ice (not only snow) at previous and pure ocean at current |
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| 146 | !!$ |
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| 147 | !!$ ial = ifvt * i1mfr + ( 1 - ifvt ) * idfr |
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| 148 | !!$! snow no ice ice ice or nothing lead fraction increases |
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| 149 | !!$! at previous now at previous |
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| 150 | !!$! -> ice aera increases ??? -> ice aera decreases ??? |
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| 151 | !!$ |
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| 152 | !!$ iadv = ( 1 - i1mfr ) * zinda |
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| 153 | !!$! pure ocean ice at |
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| 154 | !!$! at current previous |
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| 155 | !!$! -> = 1. if ice disapear between previous and current |
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| 156 | !!$ |
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| 157 | !!$ ifral = ( 1 - i1mfr * ( 1 - ial ) ) |
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| 158 | !!$! ice at ??? |
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| 159 | !!$! current |
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| 160 | !!$! -> ??? |
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| 161 | !!$ |
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| 162 | !!$ ifrdv = ( 1 - ifral * ( 1 - ial ) ) * iadv |
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| 163 | !!$! ice disapear |
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| 164 | !!$ |
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| 165 | !!$ |
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| 166 | |
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| 167 | ! computation the solar flux at ocean surface |
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| 168 | #if defined key_coupled |
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| 169 | zqsr = qsr_tot(ji,jj) + ( fstric(ji,jj) - qsr_ice(ji,jj,1) ) * ( 1.0 - pfrld(ji,jj) ) |
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| 170 | #else |
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| 171 | zqsr = pfrld(ji,jj) * qsr(ji,jj) + ( 1. - pfrld(ji,jj) ) * fstric(ji,jj) |
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| 172 | #endif |
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| 173 | ! computation the non solar heat flux at ocean surface |
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| 174 | zqns = - ( 1. - thcm(ji,jj) ) * zqsr & ! part of the solar energy used in leads |
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| 175 | & + iflt * ( fscmbq(ji,jj) + ffltbif(ji,jj) ) & |
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| 176 | & + ifral * ( ial * qcmif(ji,jj) + (1 - ial) * qldif(ji,jj) ) * r1_rdtice & |
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| 177 | & + ifrdv * ( qfvbq(ji,jj) + qdtcn(ji,jj) ) * r1_rdtice |
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| 178 | |
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| 179 | fsbbq(ji,jj) = ( 1.0 - ( ifvt + iflt ) ) * fscmbq(ji,jj) ! ??? |
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| 180 | ! |
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| 181 | qsr (ji,jj) = zqsr ! solar heat flux |
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| 182 | qns (ji,jj) = zqns - fdtcn(ji,jj) ! non solar heat flux |
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| 183 | END DO |
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| 184 | END DO |
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| 185 | |
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| 186 | CALL iom_put( 'hflx_ice_cea', - fdtcn(:,:) ) |
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| 187 | CALL iom_put( 'qns_io_cea', qns(:,:) - zqnsoce(:,:) * pfrld(:,:) ) |
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| 188 | CALL iom_put( 'qsr_io_cea', fstric(:,:) * (1.e0 - pfrld(:,:)) ) |
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| 189 | |
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| 190 | !------------------------------------------! |
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| 191 | ! mass flux at the ocean surface ! |
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| 192 | !------------------------------------------! |
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| 193 | DO jj = 1, jpj |
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| 194 | DO ji = 1, jpi |
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| 195 | ! |
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| 196 | #if defined key_coupled |
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| 197 | ! freshwater exchanges at the ice-atmosphere / ocean interface (coupled mode) |
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| 198 | zemp = emp_tot(ji,jj) - emp_ice(ji,jj) * ( 1. - pfrld(ji,jj) ) & ! |
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| 199 | & + rdmsnif(ji,jj) * r1_rdtice ! freshwaterflux due to snow melting |
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| 200 | #else |
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| 201 | ! computing freshwater exchanges at the ice/ocean interface |
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| 202 | zemp = + emp(ji,jj) * frld(ji,jj) & ! e-p budget over open ocean fraction |
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| 203 | & - tprecip(ji,jj) * ( 1. - frld(ji,jj) ) & ! liquid precipitation reaches directly the ocean |
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| 204 | & + sprecip(ji,jj) * ( 1. - pfrld(ji,jj) ) & ! taking into account change in ice cover within the time step |
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| 205 | & + rdmsnif(ji,jj) * r1_rdtice ! freshwaterflux due to snow melting |
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| 206 | ! ! ice-covered fraction: |
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| 207 | #endif |
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| 208 | ! |
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| 209 | ! computing salt exchanges at the ice/ocean interface |
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| 210 | zfons = ( soce_0(ji,jj) - sice_0(ji,jj) ) * ( rdmicif(ji,jj) * r1_rdtice ) |
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| 211 | ! |
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| 212 | ! converting the salt flux from ice to a freshwater flux from ocean |
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| 213 | zfm = zfons / ( sss_m(ji,jj) + epsi16 ) |
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| 214 | ! |
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| 215 | emps(ji,jj) = zemp + zfm ! surface ocean concentration/dilution effect (use on SSS evolution) |
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| 216 | emp (ji,jj) = zemp ! surface ocean volume flux (use on sea-surface height evolution) |
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| 217 | ! |
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| 218 | END DO |
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| 219 | END DO |
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| 220 | |
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| 221 | IF( lk_diaar5 ) THEN ! AR5 diagnostics |
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| 222 | CALL iom_put( 'isnwmlt_cea' , rdmsnif(:,:) * r1_rdtice ) |
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| 223 | CALL iom_put( 'fsal_virt_cea', soce_0(:,:) * rdmicif(:,:) * r1_rdtice ) |
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| 224 | CALL iom_put( 'fsal_real_cea', - sice_0(:,:) * rdmicif(:,:) * r1_rdtice ) |
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| 225 | ENDIF |
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| 226 | |
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| 227 | !-----------------------------------------------! |
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| 228 | ! Coupling variables ! |
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| 229 | !-----------------------------------------------! |
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| 230 | |
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| 231 | IF( lk_cpl ) THEN ! coupled case |
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| 232 | ! Ice surface temperature |
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| 233 | tn_ice(:,:,1) = sist(:,:) ! sea-ice surface temperature |
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| 234 | ! Computation of snow/ice and ocean albedo |
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| 235 | CALL albedo_ice( tn_ice, reshape( hicif, (/jpi,jpj,1/) ), reshape( hsnif, (/jpi,jpj,1/) ), zalbp, zalb ) |
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| 236 | alb_ice(:,:,1) = 0.5 * ( zalbp(:,:,1) + zalb (:,:,1) ) ! Ice albedo (mean clear and overcast skys) |
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| 237 | CALL iom_put( "icealb_cea", alb_ice(:,:,1) * fr_i(:,:) ) ! ice albedo |
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| 238 | ENDIF |
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| 239 | |
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| 240 | IF(ln_ctl) THEN ! control print |
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| 241 | CALL prt_ctl(tab2d_1=qsr , clinfo1=' lim_sbc: qsr : ', tab2d_2=qns , clinfo2=' qns : ') |
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| 242 | CALL prt_ctl(tab2d_1=emp , clinfo1=' lim_sbc: emp : ', tab2d_2=emps , clinfo2=' emps : ') |
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| 243 | CALL prt_ctl(tab2d_1=utau , clinfo1=' lim_sbc: utau : ', mask1=umask, & |
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| 244 | & tab2d_2=vtau , clinfo2=' vtau : ' , mask2=vmask ) |
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| 245 | CALL prt_ctl(tab2d_1=fr_i , clinfo1=' lim_sbc: fr_i : ', tab2d_2=tn_ice(:,:,1), clinfo2=' tn_ice : ') |
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| 246 | ENDIF |
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| 247 | ! |
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| 248 | END SUBROUTINE lim_sbc_flx_2 |
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| 249 | |
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| 250 | |
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| 251 | SUBROUTINE lim_sbc_tau_2( kt , pu_oce, pv_oce ) |
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| 252 | !!------------------------------------------------------------------- |
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| 253 | !! *** ROUTINE lim_sbc_tau *** |
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| 254 | !! |
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| 255 | !! ** Purpose : Update the ocean surface stresses due to the ice |
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| 256 | !! |
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| 257 | !! ** Action : * at each ice time step (every nn_fsbc time step): |
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| 258 | !! - compute the modulus of ice-ocean relative velocity |
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| 259 | !! at T-point (C-grid) or I-point (B-grid) |
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| 260 | !! tmod_io = rhoco * | U_ice-U_oce | |
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| 261 | !! - update the modulus of stress at ocean surface |
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| 262 | !! taum = frld * taum + (1-frld) * tmod_io * | U_ice-U_oce | |
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| 263 | !! * at each ocean time step (each kt): |
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| 264 | !! compute linearized ice-ocean stresses as |
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| 265 | !! Utau = tmod_io * | U_ice - pU_oce | |
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| 266 | !! using instantaneous current ocean velocity (usually before) |
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| 267 | !! |
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| 268 | !! NB: - the averaging operator used depends on the ice dynamics grid (cp_ice_msh='I' or 'C') |
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| 269 | !! - ice-ocean rotation angle only allowed in cp_ice_msh='I' case |
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| 270 | !! - here we make an approximation: taum is only computed every ice time step |
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| 271 | !! This avoids mutiple average to pass from T -> U,V grids and next from U,V grids |
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| 272 | !! to T grid. taum is used in TKE and GLS, which should not be too sensitive to this approximaton... |
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| 273 | !! |
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| 274 | !! ** Outputs : - utau, vtau : surface ocean i- and j-stress (u- & v-pts) updated with ice-ocean fluxes |
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| 275 | !! - taum : modulus of the surface ocean stress (T-point) updated with ice-ocean fluxes |
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| 276 | !!--------------------------------------------------------------------- |
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| 277 | INTEGER , INTENT(in) :: kt ! ocean time-step index |
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| 278 | REAL(wp), DIMENSION(jpi,jpj), INTENT(in) :: pu_oce, pv_oce ! surface ocean currents |
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| 279 | !! |
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| 280 | INTEGER :: ji, jj ! dummy loop indices |
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| 281 | REAL(wp) :: zfrldu, zat_u, zu_i, zutau_ice, zu_t, zmodt ! local scalar |
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| 282 | REAL(wp) :: zfrldv, zat_v, zv_i, zvtau_ice, zv_t, zmodi ! - - |
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| 283 | REAL(wp) :: zsang, zumt ! - - |
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| 284 | REAL(wp), DIMENSION(jpi,jpj) :: ztio_u, ztio_v ! ocean stress below sea-ice |
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| 285 | !!--------------------------------------------------------------------- |
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| 286 | ! |
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| 287 | IF( kt == nit000 .AND. lwp ) THEN ! control print |
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| 288 | WRITE(numout,*) |
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| 289 | WRITE(numout,*) 'lim_sbc_tau_2 : LIM 2.0 sea-ice - surface ocean momentum fluxes' |
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| 290 | WRITE(numout,*) '~~~~~~~~~~~~~ ' |
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| 291 | IF( lk_lim2_vp ) THEN ; WRITE(numout,*) ' VP rheology - B-grid case' |
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| 292 | ELSE ; WRITE(numout,*) ' EVP rheology - C-grid case' |
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| 293 | ENDIF |
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| 294 | ENDIF |
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| 295 | ! |
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| 296 | SELECT CASE( cp_ice_msh ) |
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| 297 | ! !-----------------------! |
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| 298 | CASE( 'I' ) ! B-grid ice dynamics ! I-point (i.e. F-point with sea-ice indexation) |
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| 299 | ! !--=--------------------! |
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| 300 | ! |
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| 301 | IF( MOD( kt-1, nn_fsbc ) == 0 ) THEN !== Ice time-step only ==! (i.e. surface module time-step) |
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| 302 | !CDIR NOVERRCHK |
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| 303 | DO jj = 1, jpj !* modulus of ice-ocean relative velocity at I-point |
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| 304 | !CDIR NOVERRCHK |
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| 305 | DO ji = 1, jpi |
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| 306 | zu_i = u_ice(ji,jj) - u_oce(ji,jj) ! ice-ocean relative velocity at I-point |
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| 307 | zv_i = v_ice(ji,jj) - v_oce(ji,jj) |
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| 308 | tmod_io(ji,jj) = SQRT( zu_i * zu_i + zv_i * zv_i ) ! modulus of this velocity (at I-point) |
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| 309 | END DO |
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| 310 | END DO |
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| 311 | !CDIR NOVERRCHK |
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| 312 | DO jj = 1, jpjm1 !* update the modulus of stress at ocean surface (T-point) |
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| 313 | !CDIR NOVERRCHK |
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| 314 | DO ji = 1, jpim1 ! NO vector opt. |
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| 315 | ! ! modulus of U_ice-U_oce at T-point |
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| 316 | zumt = 0.25_wp * ( tmod_io(ji+1,jj) + tmod_io(ji+1,jj+1) & |
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| 317 | & + tmod_io(ji,jj+1) + tmod_io(ji+1,jj+1) ) |
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| 318 | ! ! update the modulus of stress at ocean surface |
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| 319 | taum(ji,jj) = frld(ji,jj) * taum(ji,jj) + ( 1._wp - frld(ji,jj) ) * rhoco * zumt * zumt |
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| 320 | END DO |
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| 321 | END DO |
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| 322 | CALL lbc_lnk( taum, 'T', 1. ) |
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| 323 | ! |
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| 324 | utau_oce(:,:) = utau(:,:) !* save the air-ocean stresses at ice time-step |
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| 325 | vtau_oce(:,:) = vtau(:,:) |
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| 326 | ! |
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| 327 | ENDIF |
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| 328 | ! |
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| 329 | ! !== at each ocean time-step ==! |
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| 330 | ! |
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| 331 | ! !* ice/ocean stress WITH a ice-ocean rotation angle at I-point |
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| 332 | DO jj = 2, jpj |
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| 333 | zsang = SIGN( 1._wp, gphif(1,jj) ) * sangvg ! change the cosine angle sign in the SH |
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| 334 | DO ji = 2, jpi ! NO vect. opt. possible |
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| 335 | ! ... ice-ocean relative velocity at I-point using instantaneous surface ocean current at u- & v-pts |
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| 336 | zu_i = u_ice(ji,jj) - 0.5_wp * ( pu_oce(ji-1,jj ) + pu_oce(ji-1,jj-1) ) * tmu(ji,jj) |
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| 337 | zv_i = v_ice(ji,jj) - 0.5_wp * ( pv_oce(ji ,jj-1) + pv_oce(ji-1,jj-1) ) * tmu(ji,jj) |
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| 338 | ! ... components of stress with a ice-ocean rotation angle |
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| 339 | zmodi = rhoco * tmod_io(ji,jj) |
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| 340 | ztio_u(ji,jj) = zmodi * ( cangvg * zu_i - zsang * zv_i ) |
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| 341 | ztio_v(ji,jj) = zmodi * ( cangvg * zv_i + zsang * zu_i ) |
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| 342 | END DO |
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| 343 | END DO |
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| 344 | ! !* surface ocean stresses at u- and v-points |
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| 345 | DO jj = 2, jpjm1 |
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| 346 | DO ji = 2, jpim1 ! NO vector opt. |
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| 347 | ! ! ice-ocean stress at U and V-points (from I-point values) |
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| 348 | zutau_ice = 0.5_wp * ( ztio_u(ji+1,jj) + ztio_u(ji+1,jj+1) ) |
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| 349 | zvtau_ice = 0.5_wp * ( ztio_v(ji,jj+1) + ztio_v(ji+1,jj+1) ) |
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| 350 | ! ! open-ocean (lead) fraction at U- & V-points (from T-point values) |
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| 351 | zfrldu = 0.5_wp * ( frld(ji,jj) + frld(ji+1,jj ) ) |
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| 352 | zfrldv = 0.5_wp * ( frld(ji,jj) + frld(ji ,jj+1) ) |
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| 353 | ! ! update the surface ocean stress (ice-cover wheighted) |
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| 354 | utau(ji,jj) = zfrldu * utau_oce(ji,jj) + ( 1._wp - zfrldu ) * zutau_ice |
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| 355 | vtau(ji,jj) = zfrldv * vtau_oce(ji,jj) + ( 1._wp - zfrldv ) * zvtau_ice |
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| 356 | END DO |
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| 357 | END DO |
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| 358 | CALL lbc_lnk( utau, 'U', -1. ) ; CALL lbc_lnk( vtau, 'V', -1. ) ! lateral boundary condition |
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| 359 | ! |
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| 360 | ! |
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| 361 | ! !-----------------------! |
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| 362 | CASE( 'C' ) ! C-grid ice dynamics ! U & V-points (same as in the ocean) |
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| 363 | ! !--=--------------------! |
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| 364 | ! |
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| 365 | IF( MOD( kt-1, nn_fsbc ) == 0 ) THEN !== Ice time-step only ==! (i.e. surface module time-step) |
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| 366 | !CDIR NOVERRCHK |
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| 367 | DO jj = 2, jpjm1 !* modulus of the ice-ocean velocity at T-point |
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| 368 | !CDIR NOVERRCHK |
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| 369 | DO ji = fs_2, fs_jpim1 |
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| 370 | zu_t = u_ice(ji,jj) + u_ice(ji-1,jj) - u_oce(ji,jj) - u_oce(ji-1,jj) ! 2*(U_ice-U_oce) at T-point |
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| 371 | zv_t = v_ice(ji,jj) + v_ice(ji,jj-1) - v_oce(ji,jj) - v_oce(ji,jj-1) |
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| 372 | zmodt = 0.25_wp * ( zu_t * zu_t + zv_t * zv_t ) ! |U_ice-U_oce|^2 |
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| 373 | ! ! update the modulus of stress at ocean surface |
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| 374 | taum (ji,jj) = frld(ji,jj) * taum(ji,jj) + ( 1._wp - frld(ji,jj) ) * rhoco * zmodt |
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| 375 | tmod_io(ji,jj) = SQRT( zmodt ) * rhoco ! rhoco*|Uice-Uoce| |
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| 376 | END DO |
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| 377 | END DO |
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| 378 | CALL lbc_lnk( taum, 'T', 1. ) ; CALL lbc_lnk( tmod_io, 'T', 1. ) |
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| 379 | ! |
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| 380 | utau_oce(:,:) = utau(:,:) !* save the air-ocean stresses at ice time-step |
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| 381 | vtau_oce(:,:) = vtau(:,:) |
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| 382 | ! |
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| 383 | ENDIF |
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| 384 | ! |
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| 385 | ! !== at each ocean time-step ==! |
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| 386 | ! |
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| 387 | DO jj = 2, jpjm1 !* ice stress over ocean WITHOUT a ice-ocean rotation angle |
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| 388 | DO ji = fs_2, fs_jpim1 |
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| 389 | ! ! ocean area at u- & v-points |
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| 390 | zfrldu = 0.5_wp * ( frld(ji,jj) + frld(ji+1,jj ) ) |
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| 391 | zfrldv = 0.5_wp * ( frld(ji,jj) + frld(ji ,jj+1) ) |
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| 392 | ! ! quadratic drag formulation without rotation |
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| 393 | ! ! using instantaneous surface ocean current |
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| 394 | zutau_ice = 0.5 * ( tmod_io(ji,jj) + tmod_io(ji+1,jj) ) * ( u_ice(ji,jj) - pu_oce(ji,jj) ) |
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| 395 | zvtau_ice = 0.5 * ( tmod_io(ji,jj) + tmod_io(ji,jj+1) ) * ( v_ice(ji,jj) - pv_oce(ji,jj) ) |
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| 396 | ! ! update the surface ocean stress (ice-cover wheighted) |
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| 397 | utau(ji,jj) = zfrldu * utau_oce(ji,jj) + ( 1._wp - zfrldu ) * zutau_ice |
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| 398 | vtau(ji,jj) = zfrldv * vtau_oce(ji,jj) + ( 1._wp - zfrldv ) * zvtau_ice |
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| 399 | END DO |
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| 400 | END DO |
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| 401 | CALL lbc_lnk( utau, 'U', -1. ) ; CALL lbc_lnk( vtau, 'V', -1. ) ! lateral boundary condition |
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| 402 | ! |
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| 403 | END SELECT |
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| 404 | |
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| 405 | IF(ln_ctl) CALL prt_ctl( tab2d_1=utau, clinfo1=' lim_sbc: utau : ', mask1=umask, & |
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| 406 | & tab2d_2=vtau, clinfo2=' vtau : ' , mask2=vmask ) |
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| 407 | ! |
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| 408 | END SUBROUTINE lim_sbc_tau_2 |
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| 409 | |
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| 410 | #else |
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| 411 | !!---------------------------------------------------------------------- |
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| 412 | !! Default option Empty module NO LIM 2.0 sea-ice model |
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| 413 | !!---------------------------------------------------------------------- |
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| 414 | #endif |
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| 415 | |
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| 416 | !!====================================================================== |
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| 417 | END MODULE limsbc_2 |
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