1 | SUBROUTINE ice_ikaite(nlay_i) |
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2 | |
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3 | !------------------------------------------------------------------------------! |
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4 | ! *** ice_ikaite *** |
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5 | ! |
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6 | ! This routine computes precipitation / dissolution of ikaite |
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7 | ! and impacts on DIC, Alk and Ca2+ |
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8 | ! |
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9 | ! Ref: Moreau et al (JGR2015) |
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10 | ! |
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11 | ! Original code: S. Moreau, M. Vancoppenolle, 2012-2015 |
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12 | ! Rewriting: M. Vancopppenolle, Nov 2015 |
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13 | ! |
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14 | ! Solubility product formulation is valid until -9C |
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15 | ! The fit is not monotonic below -9C, so we may experience problems |
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16 | ! with ikaite below -9C |
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17 | ! |
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18 | !------------------------------------------------------------------------------! |
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19 | |
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20 | INCLUDE 'type.com' |
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21 | INCLUDE 'para.com' |
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22 | INCLUDE 'const.com' |
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23 | INCLUDE 'ice.com' |
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24 | INCLUDE 'thermo.com' |
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25 | INCLUDE 'bio.com' |
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26 | |
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27 | REAL(8), DIMENSION(nlay_bio) :: |
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28 | & Kspi |
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29 | |
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30 | LOGICAL :: |
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31 | & ln_write_bio = .TRUE. |
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32 | |
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33 | !==============================================================================! |
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34 | |
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35 | ! |
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36 | !--------------------------------------------------------------------- |
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37 | ! 1) Starting the routine |
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38 | !--------------------------------------------------------------------- |
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39 | ! |
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40 | |
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41 | IF ( ln_write_bio ) THEN |
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42 | |
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43 | WRITE(numout,*) |
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44 | WRITE(numout,*) ' *** ice_ikaite : ' |
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45 | WRITE(numout,*) ' ~~~~~~~~~~~~~~~~~' |
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46 | WRITE(numout,*) |
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47 | WRITE(numout,*) ' *** Initial values before CaCO3 precip/diss ' |
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48 | WRITE(numout,*) ' at time step : ', numit |
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49 | |
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50 | ENDIF |
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51 | |
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52 | CALL ice_brine ! get brine salinity and density |
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53 | |
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54 | CALL ice_carb_chem ! get CO32m |
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55 | |
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56 | DO jn = 1, ntra_bio |
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57 | |
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58 | ! Brine / Total gas concentrations |
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59 | DO layer = 1, nlay_bio |
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60 | c_i_bio(jn,layer) = cbu_i_bio(jn,layer) / e_i_bio(layer) |
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61 | END DO |
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62 | |
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63 | IF ( ln_write_bio ) THEN |
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64 | |
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65 | WRITE(numout,*) |
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66 | WRITE(numout,*) ' Tracer : ', biotr_i_nam(jn) |
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67 | WRITE(numout,*) ' c_i_bio: ', ( c_i_bio(jn,layer), ! concentration of tracers in bulk ice |
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68 | & layer = 1, nlay_bio ) |
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69 | WRITE(numout,*) ' cbu_i_bio: ', ( cbu_i_bio(jn,layer), ! concentration of tracers in bulk ice |
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70 | & layer = 1, nlay_bio ) |
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71 | WRITE(numout,*) |
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72 | ENDIF |
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73 | END DO |
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74 | |
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75 | ! |
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76 | !------------------------------------------------------------------------------! |
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77 | ! 2) Solubility product |
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78 | !------------------------------------------------------------------------------! |
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79 | ! |
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80 | ! Ref: Papadimitriou et al. (GCA 2013) |
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81 | ! fit valid until -9 degC |
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82 | ! non monotonic (at all) below this value |
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83 | ! we may have to regularize this |
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84 | |
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85 | DO layer = 1, nlay_bio |
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86 | |
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87 | zT = t_i_bio(layer) |
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88 | |
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89 | IF ( zt .LE. 273.15-9.) zT = 273.15-9. ! asked stathys papadim what to do here |
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90 | |
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91 | zpKsp = - 15489.09608 + 623443.70216 / zT + |
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92 | & 2355.14596 * log(zT) |
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93 | |
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94 | Kspi(layer) = 10.**(-zpKsp) ! (mol/kg)^2 of brine |
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95 | |
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96 | ! Conversion into (mmol/m3)^2 |
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97 | Kspi(layer) = Kspi(layer) * 1.0e6 * |
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98 | & rhobr_bio(layer) * rhobr_bio(layer) |
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99 | |
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100 | END DO |
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101 | |
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102 | WRITE(numout,*) ' Kspi : ', Kspi(1:nlay_bio) |
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103 | |
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104 | ! |
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105 | !------------------------------------------------------------------------------! |
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106 | ! 3) Calcification / Dissolution |
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107 | !------------------------------------------------------------------------------! |
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108 | ! |
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109 | |
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110 | DO layer = 1, nlay_bio |
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111 | |
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112 | zcal = c_i_bio(jn_cal,layer) |
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113 | ! zcal = 311.765 * sbr_bio(layer) --> approach not valid because Ca2+ changes a lot in brine in winter |
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114 | |
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115 | ! Brine concentration of CO32- |
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116 | zco32m_br = co32m(layer) / e_i_bio(layer) |
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117 | zco32m_sat = Kspi(layer) / zcal |
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118 | |
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119 | ! Saturation state (omega) in brine |
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120 | zomega = zco32m_br * zcal / Kspi(layer) |
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121 | |
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122 | ! Precipitation / dissolution |
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123 | zd_ika = ddtb / caco3_time * ( zco32m_br - zco32m_sat ) |
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124 | zd_ika = MAX( MIN(zd_ika, zco32m_br), -c_i_bio(jn_ika,layer) ) ! calcification cannot exceed CO32- stock |
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125 | ! dissolution cannot exceed ikaite stock |
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126 | zd_ika = zd_ika * e_i_bio(layer) ! bulk calcification |
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127 | |
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128 | ! Update ikaite, dic, alk and calcium bulk concentrations |
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129 | cbu_i_bio(jn_ika,layer) = cbu_i_bio(jn_ika,layer) + zd_ika |
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130 | cbu_i_bio(jn_dic,layer) = cbu_i_bio(jn_dic,layer) - zd_ika |
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131 | cbu_i_bio(jn_alk,layer) = cbu_i_bio(jn_alk,layer) - 2.*zd_ika |
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132 | cbu_i_bio(jn_cal,layer) = cbu_i_bio(jn_cal,layer) - zd_ika |
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133 | |
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134 | ! Retrieve brine concentrations |
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135 | c_i_bio(jn_ika,layer) = cbu_i_bio(jn_ika,layer)/e_i_bio(layer) |
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136 | c_i_bio(jn_dic,layer) = cbu_i_bio(jn_dic,layer)/e_i_bio(layer) |
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137 | c_i_bio(jn_alk,layer) = cbu_i_bio(jn_alk,layer)/e_i_bio(layer) |
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138 | c_i_bio(jn_cal,layer) = cbu_i_bio(jn_cal,layer)/e_i_bio(layer) |
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139 | |
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140 | ! diagnostic rate of formation and saturation state |
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141 | ika_rate(layer) = zd_ika / ddtb |
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142 | ika_omega(layer) = zomega |
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143 | |
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144 | WRITE(numout,*) ' layer, zd_ika : ', layer, zd_ika |
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145 | |
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146 | END DO |
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147 | |
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148 | ! |
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149 | !------------------------------------------------------------------------------! |
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150 | ! 5) End of the routine |
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151 | !------------------------------------------------------------------------------! |
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152 | ! |
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153 | |
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154 | WRITE(numout,*) |
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155 | WRITE(numout,*) ' ** After CaCO3 precipitation : ' |
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156 | WRITE(numout,*) ' ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ' |
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157 | WRITE(numout,*) |
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158 | |
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159 | DO jn = 1, ntra_bio |
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160 | |
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161 | IF ( ( jn .EQ. jn_dic ) .OR. |
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162 | & ( jn .EQ. jn_alk ) .OR. |
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163 | & ( jn .EQ. jn_cal ) .OR. |
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164 | & ( jn .EQ. jn_ika ) ) THEN |
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165 | WRITE(numout,*) ' Tracer : ', biotr_i_nam(jn) |
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166 | WRITE(numout,*) ' c_i_bio : ', ( c_i_bio(jn,layer), ! concentration of tracers in brines (mmol m-3) |
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167 | & layer = 1, nlay_bio ) |
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168 | WRITE(numout,*) ' cbu_i_bio: ', ( cbu_i_bio(jn,layer), ! concentration of tracers in bulk ice |
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169 | & layer = 1, nlay_bio ) |
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170 | ENDIF |
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171 | |
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172 | END DO |
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173 | |
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174 | WRITE(numout,*) |
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175 | WRITE(numout,*) ' End of ice_ikaite ' |
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176 | WRITE(numout,*) '~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~' |
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177 | |
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178 | |
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179 | !==============================================================================| |
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180 | ! End of ice_ikaite |
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181 | |
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182 | WRITE(numout,*) |
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183 | END |
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