1 | SUBROUTINE newsedim(ngrid,nlay,naersize,ptimestep, |
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2 | & pplev,masse,epaisseur,pt,rd,rho,pqi,wq) |
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3 | IMPLICIT NONE |
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4 | |
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5 | !================================================================== |
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6 | ! |
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7 | ! Purpose |
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8 | ! ------- |
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9 | ! Calculates sedimentation of 1 tracer |
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10 | ! of radius rd (m) and density rho (kg.m-3) |
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11 | ! |
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12 | !================================================================== |
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13 | |
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14 | !----------------------------------------------------------------------- |
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15 | ! declarations |
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16 | ! ------------ |
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17 | |
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18 | !#include "dimensions.h" |
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19 | !#include "dimphys.h" |
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20 | #include "comcstfi.h" |
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21 | |
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22 | ! arguments |
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23 | ! --------- |
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24 | |
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25 | integer,intent(in) :: ngrid ! number of atmospheric columns |
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26 | integer,intent(in) :: nlay ! number of atmospheric layers |
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27 | integer,intent(in) :: naersize ! number of particle sizes (1 or number |
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28 | ! of grid boxes) |
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29 | real,intent(in) :: ptimestep ! physics time step (s) |
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30 | real,intent(in) :: pplev(ngrid,nlay+1) ! inter-layer pressures (Pa) |
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31 | real,intent(in) :: pt(ngrid,nlay) ! mid-layer temperatures (K) |
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32 | real,intent(in) :: masse (ngrid,nlay) ! atmospheric mass (kg) |
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33 | real,intent(in) :: epaisseur (ngrid,nlay) ! thickness of atm. layers (m) |
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34 | real,intent(in) :: rd(naersize) ! particle radius (m) |
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35 | real,intent(in) :: rho ! particle density (kg.m-3) |
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36 | real,intent(inout) :: pqi(ngrid,nlay) ! tracer (e.g. ?/kg) |
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37 | real,intent(out) :: wq(ngrid,nlay+1) ! flux of tracer during timestep (?/m-2) |
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38 | |
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39 | c local: |
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40 | c ------ |
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41 | |
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42 | INTEGER l,ig, k, i |
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43 | REAL rfall |
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44 | |
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45 | LOGICAL,SAVE :: firstcall=.true. |
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46 | |
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47 | c Traceurs : |
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48 | c ~~~~~~~~ |
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49 | real traversee (ngrid,nlay) |
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50 | real vstokes(ngrid,nlay) |
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51 | real w(ngrid,nlay) |
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52 | real ptop, dztop, Ep, Stra |
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53 | |
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54 | |
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55 | c Physical constant |
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56 | c ~~~~~~~~~~~~~~~~~ |
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57 | c Gas molecular viscosity (N.s.m-2) |
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58 | real,parameter :: visc=1.e-5 ! CO2 |
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59 | c Effective gas molecular radius (m) |
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60 | real,parameter :: molrad=2.2e-10 ! CO2 |
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61 | |
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62 | c local and saved variable |
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63 | real,save :: a,b |
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64 | |
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65 | c ** un petit test de coherence |
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66 | c -------------------------- |
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67 | |
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68 | |
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69 | !print*,'temporary fixed particle rad in newsedim!!' |
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70 | |
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71 | IF (firstcall) THEN |
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72 | firstcall=.false. |
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73 | |
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74 | |
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75 | |
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76 | !======================================================================= |
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77 | ! Preliminary calculations for sedimenation velocity |
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78 | |
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79 | ! - Constant to compute stokes speed simple formulae |
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80 | ! (Vstokes = b * rho* r**2 avec b= (2/9) * rho * g / visc |
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81 | b = 2./9. * g / visc |
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82 | |
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83 | ! - Constant to compute gas mean free path |
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84 | ! l= (T/P)*a, avec a = ( 0.707*8.31/(4*pi*molrad**2 * avogadro)) |
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85 | a = 0.707*8.31/(4*3.1416* molrad**2 * 6.023e23) |
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86 | |
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87 | c - Correction to account for non-spherical shape (Murphy et al. 1990) |
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88 | c (correction = 0.85 for irregular particles, 0.5 for disk shaped particles) |
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89 | c a = a * 0.85 |
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90 | |
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91 | |
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92 | ENDIF |
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93 | |
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94 | c----------------------------------------------------------------------- |
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95 | c 1. initialisation |
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96 | c ----------------- |
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97 | |
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98 | c Sedimentation velocity (m/s) |
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99 | c ~~~~~~~~~~~~~~~~~~~~~~ |
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100 | c (stokes law corrected for low pressure by the Cunningham |
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101 | c slip-flow correction according to Rossow (Icarus 36, 1-50, 1978) |
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102 | |
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103 | do l=1,nlay |
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104 | do ig=1, ngrid |
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105 | if (naersize.eq.1) then |
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106 | rfall=rd(1) |
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107 | else |
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108 | i=ngrid*(l-1)+ig |
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109 | rfall=rd(i) ! how can this be correct!!? |
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110 | endif |
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111 | |
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112 | vstokes(ig,l) = b * rho * rfall**2 * |
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113 | & (1 + 1.333* ( a*pt(ig,l)/pplev(ig,l) )/rfall) |
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114 | |
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115 | c Layer crossing time (s) : |
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116 | traversee(ig,l)= epaisseur(ig,l)/vstokes(ig,l) |
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117 | end do |
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118 | end do |
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119 | |
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120 | |
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121 | c Calcul de la masse d'atmosphere correspondant a q transferee |
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122 | c ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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123 | c (e.g. on recherche le niveau en dessous de laquelle le traceur |
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124 | c va traverser le niveau intercouche l : "dztop" est sa hauteur |
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125 | c au dessus de l (m), "ptop" est sa pression (Pa)) |
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126 | do l=1,nlay |
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127 | do ig=1, ngrid |
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128 | |
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129 | dztop = vstokes(ig,l)* ptimestep |
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130 | Ep=0 |
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131 | k=0 |
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132 | w(ig,l) = 0. !! JF+AS ajout initialisation (LK MARS) |
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133 | c ************************************************************** |
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134 | c Simple Method |
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135 | cc w(ig,l) = |
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136 | cc & (1- exp(-dztop*g/(r*pt(ig,l))))*pplev(ig,l) / g |
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137 | cc write(*,*) 'OK simple method l,w =', l, w(ig,l) |
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138 | cc write(*,*) 'OK simple method dztop =', dztop |
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139 | w(ig,l) = 1. - exp(-dztop*g/(r*pt(ig,l))) |
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140 | !!! Diagnostic: JF. Fix: AS. Date: 05/11 |
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141 | !!! Probleme arrondi avec la quantite ci-dessus |
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142 | !!! ---> vaut 0 pour -dztop*g/(r*pt(ig,l)) trop petit |
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143 | !!! ---> dans ce cas on utilise le developpement limite ! |
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144 | !!! ---> exp(-x) = 1 - x lorsque x --> 0 avec une erreur de x^2 / 2 |
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145 | |
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146 | IF ( w(ig,l) .eq. 0. ) THEN |
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147 | w(ig,l) = ( dztop*g/(r*pt(ig,l)) ) * pplev(ig,l) / g |
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148 | ELSE |
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149 | w(ig,l) = w(ig,l) * pplev(ig,l) / g |
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150 | ENDIF |
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151 | ! LK borrowed simple method from Mars model (AS/JF) |
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152 | |
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153 | !************************************************************** |
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154 | cccc Complex method : |
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155 | if (dztop.gt.epaisseur(ig,l)) then |
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156 | cccc Cas ou on "epuise" la couche l : On calcule le flux |
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157 | cccc Venant de dessus en tenant compte de la variation de Vstokes |
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158 | |
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159 | Ep= epaisseur(ig,l) |
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160 | Stra= traversee(ig,l) |
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161 | do while(dztop.gt.Ep.and.l+k+1.le.nlay) |
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162 | k=k+1 |
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163 | dztop= Ep + vstokes(ig,l+k)*(ptimestep -Stra) |
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164 | Ep = Ep + epaisseur(ig,l+k) |
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165 | Stra = Stra + traversee(ig,l+k) |
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166 | enddo |
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167 | Ep = Ep - epaisseur(ig,l+k) |
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168 | ! ptop=pplev(ig,l+k)*exp(-(dztop-Ep)*g/(r*pt(ig,l+k))) |
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169 | ptop=exp(-(dztop-Ep)*g/(r*pt(ig,l+k))) |
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170 | IF ( ptop .eq. 1. ) THEN |
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171 | !PRINT*, 'newsedim: exposant trop petit ', ig, l |
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172 | ptop=pplev(ig,l+k) * ( 1. - (dztop-Ep)*g/(r*pt(ig,l+k))) |
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173 | ELSE |
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174 | ptop=pplev(ig,l+k) * ptop |
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175 | ENDIF |
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176 | |
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177 | w(ig,l) = (pplev(ig,l) - ptop)/g |
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178 | |
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179 | endif !!! complex method |
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180 | c |
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181 | cc write(*,*) 'OK new method l,w =', l, w(ig,l) |
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182 | cc write(*,*) 'OK new method dztop =', dztop |
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183 | cc if(l.eq.7)write(*,*)'l=7,k,pplev,Ptop',pplev(ig,l),Ptop |
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184 | cc if(l.eq.7)write(*,*)'l=7,dztop,Ep',dztop,Ep |
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185 | cc if(l.eq.6)write(*,*)'l=6,k, w',k, w(1,l) |
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186 | cc if(l.eq.7)write(*,*)'l=7,k, w',k, w(1,l) |
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187 | cc if(l.eq.8)write(*,*)'l=8,k, w',k, w(1,l) |
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188 | c ************************************************************** |
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189 | |
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190 | end do |
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191 | end do |
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192 | |
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193 | call vlz_fi(ngrid,nlay,pqi,2.,masse,w,wq) |
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194 | c write(*,*) ' newsed: wq(6), wq(7), q(6)', |
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195 | c & wq(1,6),wq(1,7),pqi(1,6) |
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196 | |
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197 | END |
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