[4] | 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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