1 | MODULE limthd_sal |
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2 | !!====================================================================== |
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3 | !! *** MODULE limthd_sal *** |
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4 | !! LIM-3 sea-ice : computation of salinity variations in the ice |
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5 | !!====================================================================== |
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6 | !! History : - ! 2003-05 (M. Vancoppenolle) UCL-ASTR first coding for LIM3-1D |
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7 | !! 3.0 ! 2005-12 (M. Vancoppenolle) adapted to the 3-D version |
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8 | !!--------------------------------------------------------------------- |
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9 | #if defined key_lim3 |
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10 | !!---------------------------------------------------------------------- |
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11 | !! 'key_lim3' LIM-3 sea-ice model |
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12 | !!---------------------------------------------------------------------- |
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13 | !! lim_thd_sal : salinity variations in the ice |
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14 | !!---------------------------------------------------------------------- |
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15 | USE par_oce ! ocean parameters |
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16 | USE phycst ! physical constants (ocean directory) |
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17 | USE sbc_oce ! Surface boundary condition: ocean fields |
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18 | USE ice ! LIM: sea-ice variables |
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19 | USE par_ice ! LIM: sea-ice parameters |
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20 | USE thd_ice ! LIM: sea-ice thermodynamics |
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21 | USE limvar ! LIM: sea-ice variables |
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22 | USE in_out_manager ! I/O manager |
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23 | |
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24 | IMPLICIT NONE |
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25 | PRIVATE |
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26 | |
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27 | PUBLIC lim_thd_sal ! called by limthd module |
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28 | PUBLIC lim_thd_sal_init ! called by iceini module |
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29 | |
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30 | !!---------------------------------------------------------------------- |
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31 | !! NEMO/LIM3 3.3 , UCL - NEMO Consortium (2010) |
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32 | !! $Id$ |
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33 | !! Software governed by the CeCILL licence (NEMOGCM/NEMO_CeCILL.txt) |
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34 | !!---------------------------------------------------------------------- |
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35 | CONTAINS |
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36 | |
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37 | SUBROUTINE lim_thd_sal( kideb, kiut ) |
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38 | !!------------------------------------------------------------------- |
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39 | !! *** ROUTINE lim_thd_sal *** |
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40 | !! |
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41 | !! ** Purpose : computes new salinities in the ice |
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42 | !! |
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43 | !! ** Method : 4 possibilities |
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44 | !! -> num_sal = 1 -> constant salinity for z,t |
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45 | !! -> num_sal = 2 -> S = S(z,t) [simple Vancoppenolle et al 2005] |
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46 | !! -> num_sal = 3 -> S = S(z) [multiyear ice] |
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47 | !! -> num_sal = 4 -> S = S(h) [Cox and Weeks 74] |
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48 | !!--------------------------------------------------------------------- |
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49 | INTEGER, INTENT(in) :: kideb, kiut ! thickness category index |
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50 | ! |
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51 | INTEGER :: ji, jk ! dummy loop indices |
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52 | INTEGER :: zji, zjj ! local integers |
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53 | REAL(wp) :: zsold, zeps, iflush, iaccrbo, igravdr, isnowic, i_ice_switch, ztmelts ! local scalars |
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54 | REAL(wp) :: zaaa, zbbb, zccc, zdiscrim ! local scalars |
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55 | REAL(wp), DIMENSION(jpij) :: ze_init, zhiold, zsiold ! 1D workspace |
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56 | !!--------------------------------------------------------------------- |
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57 | |
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58 | zeps=1.0e-06_wp |
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59 | |
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60 | !------------------------------------------------------------------------------| |
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61 | ! 1) Constant salinity, constant in time | |
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62 | !------------------------------------------------------------------------------| |
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63 | |
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64 | IF( num_sal == 1 ) THEN |
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65 | DO jk = 1, nlay_i |
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66 | DO ji = kideb, kiut |
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67 | s_i_b(ji,jk) = bulk_sal |
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68 | END DO ! ji |
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69 | END DO ! jk |
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70 | ! |
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71 | DO ji = kideb, kiut |
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72 | sm_i_b(ji) = bulk_sal |
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73 | END DO ! ji |
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74 | ! |
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75 | ENDIF |
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76 | |
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77 | !------------------------------------------------------------------------------| |
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78 | ! Module 2 : Constant salinity varying in time | |
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79 | !------------------------------------------------------------------------------| |
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80 | |
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81 | IF ( ( num_sal .EQ. 2 ) .OR. ( num_sal .EQ. 4 ) ) THEN |
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82 | |
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83 | ! WRITE(numout,*) |
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84 | ! WRITE(numout,*) 'lim_thd_sal : Ice salinity computation module ', & |
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85 | ! num_sal |
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86 | ! WRITE(numout,*) '~~~~~~~~~~~' |
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87 | ! WRITE(numout,*) |
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88 | |
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89 | !--------------------------------- |
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90 | ! Thickness at previous time step |
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91 | !--------------------------------- |
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92 | DO ji = kideb, kiut |
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93 | zhiold(ji) = ht_i_b(ji) - dh_i_bott(ji) - dh_snowice(ji) - & |
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94 | dh_i_surf(ji) |
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95 | END DO ! ji |
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96 | |
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97 | !--------------------- |
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98 | ! Global heat content |
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99 | !--------------------- |
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100 | |
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101 | ze_init(:) = 0.0 |
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102 | DO jk = 1, nlay_i |
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103 | DO ji = kideb, kiut |
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104 | ze_init(ji) = ze_init(ji) + q_i_b(ji,jk) * ht_i_b(ji) / nlay_i |
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105 | END DO ! ji |
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106 | END DO ! jk |
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107 | |
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108 | DO ji = kideb, kiut |
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109 | |
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110 | !---------- |
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111 | ! Switches |
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112 | !---------- |
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113 | |
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114 | ! iflush : 1 if summer |
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115 | iflush = MAX( 0.0 , SIGN ( 1.0 , t_su_b(ji) - rtt ) ) |
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116 | ! igravdr : 1 if t_su lt t_bo |
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117 | igravdr = MAX( 0.0 , SIGN ( 1.0 , t_bo_b(ji) - t_su_b(ji) ) ) |
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118 | ! iaccrbo : 1 if bottom accretion |
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119 | iaccrbo = MAX( 0.0 , SIGN ( 1.0 , dh_i_bott(ji) ) ) |
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120 | ! isnowic : 1 if snow ice formation |
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121 | i_ice_switch = 1.0 - MAX ( 0.0 , SIGN ( 1.0 , - ht_i_b(ji) + 1.0e-2 ) ) |
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122 | isnowic = 1.0 - MAX ( 0.0 , SIGN ( 1.0 , - dh_snowice(ji) ) ) * i_ice_switch |
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123 | |
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124 | !--------------------- |
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125 | ! Salinity tendencies |
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126 | !--------------------- |
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127 | |
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128 | ! drainage by gravity drainage |
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129 | dsm_i_gd_1d(ji) = - igravdr * MAX( sm_i_b(ji) - sal_G , 0._wp ) / time_G * rdt_ice |
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130 | |
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131 | ! drainage by flushing |
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132 | dsm_i_fl_1d(ji) = - iflush * MAX( sm_i_b(ji) - sal_F , 0._wp ) / time_F * rdt_ice |
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133 | |
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134 | !----------------- |
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135 | ! Update salinity |
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136 | !----------------- |
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137 | |
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138 | ! only drainage terms ( gravity drainage and flushing ) |
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139 | ! snow ice / bottom sources are added in lim_thd_ent |
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140 | ! to conserve energy |
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141 | zsiold(ji) = sm_i_b(ji) |
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142 | sm_i_b(ji) = sm_i_b(ji) + dsm_i_fl_1d(ji) + dsm_i_gd_1d(ji) |
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143 | |
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144 | ! if no ice, salinity eq 0.1 |
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145 | i_ice_switch = 1._wp - MAX ( 0._wp, SIGN( 1._wp , - ht_i_b(ji) ) ) |
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146 | sm_i_b(ji) = i_ice_switch*sm_i_b(ji) + s_i_min * ( 1._wp - i_ice_switch ) |
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147 | END DO ! ji |
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148 | |
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149 | ! Salinity profile |
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150 | CALL lim_var_salprof1d( kideb, kiut ) |
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151 | |
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152 | !---------------------------- |
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153 | ! Heat flux - brine drainage |
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154 | !---------------------------- |
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155 | |
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156 | DO ji = kideb, kiut |
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157 | ! iflush : 1 if summer |
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158 | iflush = MAX( 0._wp , SIGN ( 1._wp , t_su_b(ji) - rtt ) ) |
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159 | ! igravdr : 1 if t_su lt t_bo |
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160 | igravdr = MAX( 0._wp , SIGN ( 1._wp , t_bo_b(ji) - t_su_b(ji) ) ) |
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161 | ! iaccrbo : 1 if bottom accretion |
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162 | iaccrbo = MAX( 0._wp , SIGN ( 1._wp , dh_i_bott(ji) ) ) |
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163 | ! |
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164 | fhbri_1d(ji) = 0._wp |
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165 | END DO ! ji |
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166 | |
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167 | !---------------------------- |
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168 | ! Salt flux - brine drainage |
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169 | !---------------------------- |
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170 | DO ji = kideb, kiut |
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171 | i_ice_switch = 1._wp - MAX ( 0._wp, SIGN( 1._wp , - ht_i_b(ji) ) ) |
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172 | fsbri_1d(ji) = fsbri_1d(ji) - i_ice_switch * rhoic * a_i_b(ji) * ht_i_b(ji) & |
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173 | & * ( MAX(dsm_i_gd_1d(ji) + dsm_i_fl_1d(ji), sm_i_b(ji) - zsiold(ji) ) ) / rdt_ice |
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174 | IF( num_sal == 4 ) fsbri_1d(ji) = 0._wp |
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175 | END DO ! ji |
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176 | |
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177 | ! Only necessary for conservation check since salinity is modified |
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178 | !-------------------- |
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179 | ! Temperature update |
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180 | !-------------------- |
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181 | DO jk = 1, nlay_i |
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182 | DO ji = kideb, kiut |
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183 | ztmelts = -tmut*s_i_b(ji,jk) + rtt |
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184 | !Conversion q(S,T) -> T (second order equation) |
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185 | zaaa = cpic |
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186 | zbbb = ( rcp - cpic ) * ( ztmelts - rtt ) + q_i_b(ji,jk) / rhoic - lfus |
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187 | zccc = lfus * ( ztmelts - rtt ) |
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188 | zdiscrim = SQRT( MAX(zbbb*zbbb - 4.0*zaaa*zccc,0.0) ) |
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189 | t_i_b(ji,jk) = rtt - ( zbbb + zdiscrim ) / ( 2.0 *zaaa ) |
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190 | END DO !ji |
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191 | END DO !jk |
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192 | ! |
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193 | ENDIF ! num_sal .EQ. 2 |
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194 | |
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195 | !------------------------------------------------------------------------------| |
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196 | ! Module 3 : Profile of salinity, constant in time | |
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197 | !------------------------------------------------------------------------------| |
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198 | |
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199 | IF( num_sal .EQ. 3 ) THEN |
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200 | |
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201 | WRITE(numout,*) |
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202 | WRITE(numout,*) 'lim_thd_sal : Ice salinity computation module ', & |
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203 | num_sal |
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204 | WRITE(numout,*) '~~~~~~~~~~~~' |
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205 | |
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206 | CALL lim_var_salprof1d(kideb,kiut) |
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207 | |
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208 | ENDIF ! num_sal .EQ. 3 |
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209 | |
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210 | !------------------------------------------------------------------------------| |
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211 | ! Module 4 : Constant salinity varying in time | |
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212 | !------------------------------------------------------------------------------| |
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213 | |
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214 | ! Cox and Weeks, 1974 |
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215 | IF (num_sal.eq.5) THEN |
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216 | |
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217 | WRITE(numout,*) |
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218 | WRITE(numout,*) 'lim_thd_sal : Ice salinity computation module ', & |
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219 | num_sal |
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220 | WRITE(numout,*) '~~~~~~~~~~~~' |
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221 | |
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222 | DO ji = kideb, kiut |
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223 | |
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224 | zsold = sm_i_b(ji) |
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225 | |
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226 | IF (ht_i_b(ji).lt.0.4) THEN |
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227 | sm_i_b(ji) = 14.24 - 19.39*ht_i_b(ji) |
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228 | ELSE |
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229 | sm_i_b(ji) = 7.88 - 1.59*ht_i_b(ji) |
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230 | sm_i_b(ji) = MIN(sm_i_b(ji),zsold) |
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231 | ENDIF |
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232 | |
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233 | IF ( ht_i_b(ji) .GT. 3.06918239 ) THEN |
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234 | sm_i_b(ji) = 3.0 |
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235 | ENDIF |
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236 | |
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237 | DO jk = 1, nlay_i |
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238 | s_i_b(ji,jk) = sm_i_b(ji) |
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239 | END DO |
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240 | |
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241 | END DO ! ji |
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242 | |
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243 | ENDIF ! num_sal |
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244 | |
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245 | !------------------------------------------------------------------------------| |
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246 | ! 5) Computation of salt flux due to Bottom growth |
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247 | !------------------------------------------------------------------------------| |
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248 | |
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249 | IF ( num_sal .EQ. 4 ) THEN |
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250 | DO ji = kideb, kiut |
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251 | zji = MOD( npb(ji) - 1, jpi ) + 1 |
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252 | zjj = ( npb(ji) - 1 ) / jpi + 1 |
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253 | fseqv_1d(ji) = fseqv_1d(ji) + ( sss_m(zji,zjj) - bulk_sal ) & |
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254 | & * rhoic * a_i_b(ji) * MAX( dh_i_bott(ji) , 0.0 ) / rdt_ice |
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255 | END DO |
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256 | ELSE |
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257 | DO ji = kideb, kiut |
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258 | zji = MOD( npb(ji) - 1, jpi ) + 1 |
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259 | zjj = ( npb(ji) - 1 ) / jpi + 1 |
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260 | fseqv_1d(ji) = fseqv_1d(ji) + ( sss_m(zji,zjj) - s_i_new(ji) ) & |
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261 | & * rhoic * a_i_b(ji) * MAX( dh_i_bott(ji) , 0.0 ) / rdt_ice |
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262 | END DO ! ji |
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263 | ENDIF |
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264 | ! |
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265 | END SUBROUTINE lim_thd_sal |
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266 | |
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267 | |
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268 | SUBROUTINE lim_thd_sal_init |
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269 | !!------------------------------------------------------------------- |
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270 | !! *** ROUTINE lim_thd_sal_init *** |
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271 | !! |
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272 | !! ** Purpose : initialization of ice salinity parameters |
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273 | !! |
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274 | !! ** Method : Read the namicesal namelist and check the parameter |
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275 | !! values called at the first timestep (nit000) |
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276 | !! |
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277 | !! ** input : Namelist namicesal |
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278 | !!------------------------------------------------------------------- |
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279 | NAMELIST/namicesal/ num_sal, bulk_sal, sal_G, time_G, sal_F, time_F, & |
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280 | & s_i_max, s_i_min, s_i_0, s_i_1 |
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281 | !!------------------------------------------------------------------- |
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282 | ! |
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283 | REWIND( numnam_ice ) ! Read Namelist namicesal |
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284 | READ ( numnam_ice , namicesal ) |
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285 | ! |
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286 | IF(lwp) THEN ! control print |
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287 | WRITE(numout,*) |
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288 | WRITE(numout,*) 'lim_thd_sal_init : Ice parameters for salinity ' |
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289 | WRITE(numout,*) '~~~~~~~~~~~~~~~~' |
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290 | WRITE(numout,*) ' switch for salinity num_sal : ', num_sal |
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291 | WRITE(numout,*) ' bulk salinity value if num_sal = 1 : ', bulk_sal |
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292 | WRITE(numout,*) ' restoring salinity for GD : ', sal_G |
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293 | WRITE(numout,*) ' restoring time for GD : ', time_G |
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294 | WRITE(numout,*) ' restoring salinity for flushing : ', sal_F |
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295 | WRITE(numout,*) ' restoring time for flushing : ', time_F |
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296 | WRITE(numout,*) ' Maximum tolerated ice salinity : ', s_i_max |
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297 | WRITE(numout,*) ' Minimum tolerated ice salinity : ', s_i_min |
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298 | WRITE(numout,*) ' 1st salinity for salinity profile : ', s_i_0 |
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299 | WRITE(numout,*) ' 2nd salinity for salinity profile : ', s_i_1 |
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300 | ENDIF |
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301 | ! |
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302 | END SUBROUTINE lim_thd_sal_init |
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303 | |
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304 | #else |
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305 | !!---------------------------------------------------------------------- |
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306 | !! Default option Dummy Module No LIM-3 sea-ice model |
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307 | !!---------------------------------------------------------------------- |
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308 | #endif |
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309 | !!====================================================================== |
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310 | END MODULE limthd_sal |
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