1 | SUBROUTINE soil(ptimestep, indice, snow, ptsrf, ptsoil, |
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2 | s pcapcal, pfluxgrd) |
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3 | IMPLICIT NONE |
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4 | |
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5 | c======================================================================= |
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6 | c |
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7 | c Auteur: Frederic Hourdin 30/01/92 |
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8 | c ------- |
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9 | c |
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10 | c objet: computation of : the soil temperature evolution |
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11 | c ------ the surfacic heat capacity "Capcal" |
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12 | c the surface conduction flux pcapcal |
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13 | c |
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14 | c |
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15 | c Method: implicit time integration |
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16 | c ------- |
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17 | c Consecutive ground temperatures are related by: |
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18 | c T(k+1) = C(k) + D(k)*T(k) (1) |
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19 | c the coefficients C and D are computed at the t-dt time-step. |
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20 | c Routine structure: |
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21 | c 1)new temperatures are computed using (1) |
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22 | c 2)C and D coefficients are computed from the new temperature |
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23 | c profile for the t+dt time-step |
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24 | c 3)the coefficients A and B are computed where the diffusive |
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25 | c fluxes at the t+dt time-step is given by |
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26 | c Fdiff = A + B Ts(t+dt) |
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27 | c or Fdiff = F0 + Capcal (Ts(t+dt)-Ts(t))/dt |
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28 | c with F0 = A + B (Ts(t)) |
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29 | c Capcal = B*dt |
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30 | c |
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31 | c Interface: |
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32 | c ---------- |
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33 | c |
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34 | c Arguments: |
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35 | c ---------- |
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36 | c ptimestep physical timestep (s) |
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37 | c indice sub-surface index |
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38 | c snow(klon,nbsrf) snow |
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39 | c ptsrf(klon) surface temperature at time-step t (K) |
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40 | c ptsoil(klon,nsoilmx) temperature inside the ground (K) |
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41 | c pcapcal(klon) surfacic specific heat (W*m-2*s*K-1) |
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42 | c pfluxgrd(klon) surface diffusive flux from ground (Wm-2) |
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43 | c |
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44 | c======================================================================= |
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45 | c declarations: |
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46 | c ------------- |
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47 | |
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48 | #include "dimensions.h" |
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49 | #include "dimphy.h" |
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50 | #include "dimsoil.h" |
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51 | #include "indicesol.h" |
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52 | |
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53 | c----------------------------------------------------------------------- |
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54 | c arguments |
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55 | c --------- |
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56 | |
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57 | REAL ptimestep |
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58 | INTEGER indice |
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59 | REAL ptsrf(klon),ptsoil(klon,nsoilmx),snow(klon) |
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60 | REAL pcapcal(klon),pfluxgrd(klon) |
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61 | |
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62 | c----------------------------------------------------------------------- |
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63 | c local arrays |
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64 | c ------------ |
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65 | |
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66 | INTEGER ig,jk |
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67 | REAL zdz2(nsoilmx),z1(klon) |
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68 | REAL min_period,dalph_soil |
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69 | REAL ztherm_i(klon) |
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70 | |
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71 | c local saved variables: |
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72 | c ---------------------- |
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73 | REAL dz1(nsoilmx),dz2(nsoilmx) |
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74 | REAL zc(klon,nsoilmx),zd(klon,nsoilmx) |
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75 | REAL lambda |
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76 | SAVE dz1,dz2,zc,zd,lambda |
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77 | LOGICAL firstcall |
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78 | SAVE firstcall |
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79 | REAL isol,isno,iice |
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80 | SAVE isol,isno,iice |
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81 | |
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82 | DATA firstcall/.true./ |
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83 | |
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84 | DATA isol,isno,iice/2000.,2000.,2000./ |
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85 | |
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86 | c----------------------------------------------------------------------- |
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87 | c Depthts: |
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88 | c -------- |
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89 | |
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90 | REAL fz,rk,fz1,rk1,rk2 |
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91 | fz(rk)=fz1*(dalph_soil**rk-1.)/(dalph_soil-1.) |
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92 | |
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93 | c calcul de l'inertie thermique a partir de la variable rnat. |
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94 | c on initialise a iice meme au-dessus d'un point de mer au cas |
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95 | c ou le point de mer devienne point de glace au pas suivant |
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96 | c on corrige si on a un point de terre avec ou sans glace |
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97 | c |
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98 | IF (indice.EQ.is_sic) THEN |
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99 | DO ig = 1, klon |
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100 | ztherm_i(ig) = iice |
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101 | IF (snow(ig).GT.0.0) ztherm_i(ig) = isno |
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102 | ENDDO |
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103 | ELSE IF (indice.EQ.is_lic) THEN |
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104 | DO ig = 1, klon |
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105 | ztherm_i(ig) = iice |
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106 | IF (snow(ig).GT.0.0) ztherm_i(ig) = isno |
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107 | ENDDO |
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108 | ELSE IF (indice.EQ.is_ter) THEN |
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109 | DO ig = 1, klon |
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110 | ztherm_i(ig) = isol |
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111 | IF (snow(ig).GT.0.0) ztherm_i(ig) = isno |
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112 | ENDDO |
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113 | ELSE IF (indice.EQ.is_oce) THEN |
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114 | DO ig = 1, klon |
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115 | ztherm_i(ig) = iice |
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116 | ENDDO |
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117 | ELSE |
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118 | PRINT*, "valeur d indice non prevue", indice |
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119 | CALL abort |
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120 | ENDIF |
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121 | |
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122 | |
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123 | IF (firstcall) THEN |
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124 | |
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125 | c----------------------------------------------------------------------- |
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126 | c ground levels |
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127 | c grnd=z/l where l is the skin depth of the diurnal cycle: |
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128 | c -------------------------------------------------------- |
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129 | |
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130 | min_period=1800. ! en secondes |
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131 | dalph_soil=2. ! rapport entre les epaisseurs de 2 couches succ. |
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132 | |
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133 | OPEN(99,file='soil.def',status='old',form='formatted',err=9999) |
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134 | READ(99,*) min_period |
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135 | READ(99,*) dalph_soil |
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136 | PRINT*,'Discretization for the soil model' |
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137 | PRINT*,'First level e-folding depth',min_period, |
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138 | s ' dalph',dalph_soil |
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139 | CLOSE(99) |
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140 | 9999 CONTINUE |
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141 | |
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142 | c la premiere couche represente un dixieme de cycle diurne |
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143 | fz1=sqrt(min_period/3.14) |
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144 | |
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145 | DO jk=1,nsoilmx |
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146 | rk1=jk |
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147 | rk2=jk-1 |
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148 | dz2(jk)=fz(rk1)-fz(rk2) |
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149 | ENDDO |
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150 | DO jk=1,nsoilmx-1 |
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151 | rk1=jk+.5 |
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152 | rk2=jk-.5 |
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153 | dz1(jk)=1./(fz(rk1)-fz(rk2)) |
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154 | ENDDO |
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155 | lambda=fz(.5)*dz1(1) |
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156 | PRINT*,'full layers, intermediate layers (seconds)' |
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157 | DO jk=1,nsoilmx |
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158 | rk=jk |
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159 | rk1=jk+.5 |
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160 | rk2=jk-.5 |
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161 | PRINT *,'fz=', |
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162 | . fz(rk1)*fz(rk2)*3.14,fz(rk)*fz(rk)*3.14 |
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163 | ENDDO |
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164 | |
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165 | firstcall =.false. |
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166 | |
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167 | c Initialisations: |
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168 | c ---------------- |
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169 | |
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170 | ELSE !--not firstcall |
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171 | c----------------------------------------------------------------------- |
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172 | c Computation of the soil temperatures using the Cgrd and Dgrd |
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173 | c coefficient computed at the previous time-step: |
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174 | c ----------------------------------------------- |
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175 | |
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176 | c surface temperature |
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177 | DO ig=1,klon |
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178 | ptsoil(ig,1)=(lambda*zc(ig,1)+ptsrf(ig))/ |
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179 | s (lambda*(1.-zd(ig,1))+1.) |
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180 | ENDDO |
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181 | |
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182 | c other temperatures |
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183 | DO jk=1,nsoilmx-1 |
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184 | DO ig=1,klon |
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185 | ptsoil(ig,jk+1)=zc(ig,jk)+zd(ig,jk)*ptsoil(ig,jk) |
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186 | ENDDO |
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187 | ENDDO |
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188 | |
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189 | ENDIF !--not firstcall |
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190 | c----------------------------------------------------------------------- |
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191 | c Computation of the Cgrd and Dgrd coefficient for the next step: |
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192 | c --------------------------------------------------------------- |
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193 | |
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194 | DO jk=1,nsoilmx |
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195 | zdz2(jk)=dz2(jk)/ptimestep |
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196 | ENDDO |
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197 | |
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198 | DO ig=1,klon |
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199 | z1(ig)=zdz2(nsoilmx)+dz1(nsoilmx-1) |
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200 | zc(ig,nsoilmx-1)=zdz2(nsoilmx)*ptsoil(ig,nsoilmx)/z1(ig) |
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201 | zd(ig,nsoilmx-1)=dz1(nsoilmx-1)/z1(ig) |
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202 | ENDDO |
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203 | |
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204 | DO jk=nsoilmx-1,2,-1 |
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205 | DO ig=1,klon |
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206 | z1(ig)=1./(zdz2(jk)+dz1(jk-1)+dz1(jk)*(1.-zd(ig,jk))) |
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207 | zc(ig,jk-1)= |
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208 | s (ptsoil(ig,jk)*zdz2(jk)+dz1(jk)*zc(ig,jk))*z1(ig) |
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209 | zd(ig,jk-1)=dz1(jk-1)*z1(ig) |
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210 | ENDDO |
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211 | ENDDO |
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212 | |
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213 | c----------------------------------------------------------------------- |
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214 | c computation of the surface diffusive flux from ground and |
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215 | c calorific capacity of the ground: |
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216 | c --------------------------------- |
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217 | |
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218 | DO ig=1,klon |
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219 | pfluxgrd(ig)=ztherm_i(ig)*dz1(1)* |
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220 | s (zc(ig,1)+(zd(ig,1)-1.)*ptsoil(ig,1)) |
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221 | pcapcal(ig)=ztherm_i(ig)* |
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222 | s (dz2(1)+ptimestep*(1.-zd(ig,1))*dz1(1)) |
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223 | z1(ig)=lambda*(1.-zd(ig,1))+1. |
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224 | pcapcal(ig)=pcapcal(ig)/z1(ig) |
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225 | pfluxgrd(ig)=pfluxgrd(ig) |
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226 | s +pcapcal(ig)*(ptsoil(ig,1)*z1(ig)-lambda*zc(ig,1)-ptsrf(ig)) |
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227 | s /ptimestep |
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228 | ENDDO |
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229 | |
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230 | RETURN |
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231 | END |
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