[2794] | 1 | subroutine soil_pem(ngrid,nsoil,firstcall, & |
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| 2 | therm_i, & |
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| 3 | timestep,tsurf,tsoil,alph_PEM,beta_PEM) |
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| 4 | |
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| 5 | |
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| 6 | use comsoil_h_PEM, only: layer_PEM, mlayer_PEM, & |
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| 7 | mthermdiff_PEM, thermdiff_PEM, coefq_PEM, & |
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| 8 | coefd_PEM, mu_PEM,fluxgeo |
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| 9 | use comsoil_h,only: volcapa |
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| 10 | implicit none |
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| 11 | |
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| 12 | !----------------------------------------------------------------------- |
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| 13 | ! Author: LL |
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| 14 | ! Purpose: Compute soil temperature using an implict 1st order scheme |
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| 15 | ! |
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| 16 | ! Note: depths of layers and mid-layers, soil thermal inertia and |
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| 17 | ! heat capacity are commons in comsoil_PEM.h |
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| 18 | ! A convergence loop is added until equilibrium |
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| 19 | !----------------------------------------------------------------------- |
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| 20 | |
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| 21 | #include "dimensions.h" |
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| 22 | !#include "dimphys.h" |
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| 23 | |
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| 24 | !#include"comsoil.h" |
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| 25 | |
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| 26 | |
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| 27 | !----------------------------------------------------------------------- |
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| 28 | ! arguments |
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| 29 | ! --------- |
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| 30 | ! inputs: |
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| 31 | integer,intent(in) :: ngrid ! number of (horizontal) grid-points |
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| 32 | integer,intent(in) :: nsoil ! number of soil layers |
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| 33 | logical,intent(in) :: firstcall ! identifier for initialization call |
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| 34 | real,intent(in) :: therm_i(ngrid,nsoil) ! thermal inertia |
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| 35 | real,intent(in) :: timestep ! time step |
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| 36 | real,intent(in) :: tsurf(ngrid) ! surface temperature |
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| 37 | |
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| 38 | ! outputs: |
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| 39 | real,intent(inout) :: tsoil(ngrid,nsoil) ! soil (mid-layer) temperature |
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| 40 | real,intent(inout) :: alph_PEM(ngrid,nsoil-1) |
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| 41 | real,intent(inout) :: beta_PEM(ngrid,nsoil-1) |
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| 42 | |
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| 43 | |
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| 44 | |
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| 45 | |
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| 46 | |
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| 47 | ! local variables: |
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| 48 | integer ig,ik |
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| 49 | |
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| 50 | |
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| 51 | |
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| 52 | |
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| 53 | ! 0. Initialisations and preprocessing step |
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| 54 | if (firstcall) then |
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| 55 | |
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| 56 | ! 0.1 Build mthermdiff_PEM(:), the mid-layer thermal diffusivities |
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| 57 | do ig=1,ngrid |
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| 58 | do ik=0,nsoil-1 |
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| 59 | mthermdiff_PEM(ig,ik)=therm_i(ig,ik+1)*therm_i(ig,ik+1)/volcapa |
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| 60 | |
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| 61 | enddo |
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| 62 | enddo |
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| 63 | |
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| 64 | |
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| 65 | ! 0.2 Build thermdiff(:), the "interlayer" thermal diffusivities |
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| 66 | do ig=1,ngrid |
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| 67 | do ik=1,nsoil-1 |
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| 68 | thermdiff_PEM(ig,ik)=((layer_PEM(ik)-mlayer_PEM(ik-1))*mthermdiff_PEM(ig,ik) & |
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| 69 | +(mlayer_PEM(ik)-layer_PEM(ik))*mthermdiff_PEM(ig,ik-1)) & |
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| 70 | /(mlayer_PEM(ik)-mlayer_PEM(ik-1)) |
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| 71 | |
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| 72 | enddo |
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| 73 | enddo |
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| 74 | |
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| 75 | ! 0.3 Build coefficients mu_PEM, q_{k+1/2}, d_k, alph_PEMa_k and capcal |
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| 76 | ! mu_PEM |
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| 77 | mu_PEM=mlayer_PEM(0)/(mlayer_PEM(1)-mlayer_PEM(0)) |
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| 78 | |
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| 79 | ! q_{1/2} |
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| 80 | coefq_PEM(0)=volcapa*layer_PEM(1)/timestep |
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| 81 | ! q_{k+1/2} |
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| 82 | do ik=1,nsoil-1 |
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| 83 | coefq_PEM(ik)=volcapa*(layer_PEM(ik+1)-layer_PEM(ik)) & |
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| 84 | /timestep |
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| 85 | enddo |
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| 86 | |
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| 87 | do ig=1,ngrid |
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| 88 | ! d_k |
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| 89 | do ik=1,nsoil-1 |
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| 90 | coefd_PEM(ig,ik)=thermdiff_PEM(ig,ik)/(mlayer_PEM(ik)-mlayer_PEM(ik-1)) |
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| 91 | enddo |
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| 92 | |
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| 93 | ! alph_PEM_{N-1} |
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| 94 | alph_PEM(ig,nsoil-1)=coefd_PEM(ig,nsoil-1)/ & |
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| 95 | (coefq_PEM(nsoil-1)+coefd_PEM(ig,nsoil-1)) |
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| 96 | ! alph_PEM_k |
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| 97 | do ik=nsoil-2,1,-1 |
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| 98 | alph_PEM(ig,ik)=coefd_PEM(ig,ik)/(coefq_PEM(ik)+coefd_PEM(ig,ik+1)* & |
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| 99 | (1.-alph_PEM(ig,ik+1))+coefd_PEM(ig,ik)) |
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| 100 | enddo |
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| 101 | |
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| 102 | |
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| 103 | enddo ! of do ig=1,ngrid |
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| 104 | |
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| 105 | |
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| 106 | |
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| 107 | endif ! of if (firstcall) |
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| 108 | |
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| 109 | |
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| 110 | |
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| 111 | IF (.not.firstcall) THEN |
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| 112 | ! 2. Compute soil temperatures |
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| 113 | ! First layer: |
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| 114 | |
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| 115 | |
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| 116 | |
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| 117 | |
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| 118 | do ig=1,ngrid |
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| 119 | tsoil(ig,1)=(tsurf(ig)+mu_PEM*beta_PEM(ig,1)* & |
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| 120 | thermdiff_PEM(ig,1)/mthermdiff_PEM(ig,0))/ & |
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| 121 | (1.+mu_PEM*(1.0-alph_PEM(ig,1))*& |
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| 122 | thermdiff_PEM(ig,1)/mthermdiff_PEM(ig,0)) |
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| 123 | |
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| 124 | |
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| 125 | |
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| 126 | |
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| 127 | |
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| 128 | ! Other layers: |
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| 129 | do ik=1,nsoil-1 |
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| 130 | |
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| 131 | tsoil(ig,ik+1)=alph_PEM(ig,ik)*tsoil(ig,ik)+beta_PEM(ig,ik) |
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| 132 | |
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| 133 | |
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| 134 | enddo |
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| 135 | |
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| 136 | enddo |
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| 137 | ENDIF |
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| 138 | |
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| 139 | |
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| 140 | |
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| 141 | |
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| 142 | ! 2. Compute beta_PEM coefficients (preprocessing for next time step) |
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| 143 | ! Bottom layer, beta_PEM_{N-1} |
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| 144 | do ig=1,ngrid |
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| 145 | beta_PEM(ig,nsoil-1)=coefq_PEM(nsoil-1)*tsoil(ig,nsoil) & |
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| 146 | /(coefq_PEM(nsoil-1)+coefd_PEM(ig,nsoil-1)) & |
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| 147 | + fluxgeo/(coefq_PEM(nsoil-1)+coefd_PEM(ig,nsoil-1)) |
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| 148 | enddo |
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| 149 | ! Other layers |
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| 150 | do ik=nsoil-2,1,-1 |
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| 151 | do ig=1,ngrid |
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| 152 | beta_PEM(ig,ik)=(coefq_PEM(ik)*tsoil(ig,ik+1)+ & |
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| 153 | coefd_PEM(ig,ik+1)*beta_PEM(ig,ik+1))/ & |
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| 154 | (coefq_PEM(ik)+coefd_PEM(ig,ik+1)*(1.0-alph_PEM(ig,ik+1)) & |
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| 155 | +coefd_PEM(ig,ik)) |
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| 156 | enddo |
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| 157 | enddo |
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| 158 | |
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| 159 | |
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| 160 | |
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| 161 | end |
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| 162 | |
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