| 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 | c----------------------------------------------------------------------- |
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| 15 | c declarations: |
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| 16 | c ------------- |
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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 | c |
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| 22 | c arguments: |
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| 23 | c ---------- |
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| 24 | |
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| 25 | INTEGER ngrid,nlay,naersize |
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| 26 | REAL ptimestep ! pas de temps physique (s) |
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| 27 | REAL pplev(ngrid,nlay+1) ! pression aux inter-couches (Pa) |
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| 28 | REAL pt(ngrid,nlay) ! temperature au centre des couches (K) |
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| 29 | real masse (ngrid,nlay) ! masse d'une couche (kg) |
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| 30 | real epaisseur (ngrid,nlay) ! epaisseur d'une couche (m) |
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| 31 | real rd(naersize) ! particle radius (m) |
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| 32 | real rho ! particle density (kg.m-3) |
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| 33 | |
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| 34 | |
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| 35 | c Traceurs : |
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| 36 | real pqi(ngrid,nlay) ! traceur (e.g. ?/kg) |
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| 37 | real wq(ngridmx,nlay+1) ! flux de traceur durant 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 firstcall |
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| 46 | SAVE firstcall |
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| 47 | |
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| 48 | c Traceurs : |
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| 49 | c ~~~~~~~~ |
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| 50 | real traversee (ngridmx,nlayermx) |
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| 51 | real vstokes(ngridmx,nlayermx) |
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| 52 | real w(ngridmx,nlayermx) |
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| 53 | real ptop, dztop, Ep, Stra |
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| 54 | |
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| 55 | DATA firstcall/.true./ |
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| 56 | |
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| 57 | c Physical constant |
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| 58 | c ~~~~~~~~~~~~~~~~~ |
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| 59 | ! REAL visc, molrad |
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| 60 | c Gas molecular viscosity (N.s.m-2) |
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| 61 | ! data visc/1.e-5/ ! CO2 |
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| 62 | c Effective gas molecular radius (m) |
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| 63 | ! data molrad/2.2e-10/ ! CO2 |
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| 64 | |
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| 65 | c local and saved variable |
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| 66 | real a,b |
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| 67 | save a,b |
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| 68 | |
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| 69 | c ** un petit test de coherence |
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| 70 | c -------------------------- |
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| 71 | |
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| 72 | IF (firstcall) THEN |
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| 73 | IF(ngrid.NE.ngridmx) THEN |
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| 74 | PRINT*,'STOP dans newsedim' |
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| 75 | PRINT*,'probleme de dimensions :' |
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| 76 | PRINT*,'ngrid =',ngrid |
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| 77 | PRINT*,'ngridmx =',ngridmx |
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| 78 | STOP |
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| 79 | ENDIF |
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| 80 | firstcall=.false. |
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| 81 | |
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| 82 | |
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| 83 | !======================================================================= |
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| 84 | ! Preliminary calculations for sedimenation velocity |
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| 85 | |
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| 86 | ! - Constant to compute stokes speed simple formulae |
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| 87 | ! (Vstokes = b * rho* r**2 avec b= (2/9) * rho * g / visc |
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| 88 | b = 2./9. * g / visc |
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| 89 | |
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| 90 | ! - Constant to compute gas mean free path |
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| 91 | ! l= (T/P)*a, avec a = ( 0.707*8.31/(4*pi*molrad**2 * avogadro)) |
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| 92 | a = 0.707*8.31/(4*3.1416* molrad**2 * 6.023e23) |
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| 93 | |
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| 94 | c - Correction to account for non-spherical shape (Murphy et al. 1990) |
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| 95 | c (correction = 0.85 for irregular particles, 0.5 for disk shaped particles) |
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| 96 | c a = a * 0.85 |
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| 97 | ENDIF |
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| 98 | |
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| 99 | |
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| 100 | |
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| 101 | |
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| 102 | |
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| 103 | c----------------------------------------------------------------------- |
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| 104 | c 1. initialisation |
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| 105 | c ----------------- |
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| 106 | |
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| 107 | c Sedimentation velocity (m/s) |
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| 108 | c ~~~~~~~~~~~~~~~~~~~~~~ |
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| 109 | c (stokes law corrected for low pressure by the Cunningham |
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| 110 | c slip-flow correction according to Rossow (Icarus 36, 1-50, 1978) |
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| 111 | |
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| 112 | do l=1,nlay |
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| 113 | do ig=1, ngrid |
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| 114 | if (naersize.eq.1) then |
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| 115 | rfall=rd(1) |
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| 116 | else |
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| 117 | i=ngrid*(l-1)+ig |
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| 118 | rfall=rd(i) |
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| 119 | endif |
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| 120 | vstokes(ig,l) = b * rho * rfall**2 * |
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| 121 | & (1 + 1.333* ( a*pt(ig,l)/pplev(ig,l) )/rfall) |
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| 122 | |
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| 123 | c Layer crossing time (s) : |
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| 124 | traversee(ig,l)= epaisseur(ig,l)/vstokes(ig,l) |
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| 125 | end do |
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| 126 | end do |
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| 127 | |
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| 128 | |
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| 129 | c Calcul de la masse d'atmosphere correspondant a q transferee |
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| 130 | c ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 131 | c (e.g. on recherche le niveau en dessous de laquelle le traceur |
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| 132 | c va traverser le niveau intercouche l : "dztop" est sa hauteur |
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| 133 | c au dessus de l (m), "ptop" est sa pression (Pa)) |
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| 134 | |
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| 135 | do l=1,nlay |
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| 136 | do ig=1, ngrid |
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| 137 | |
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| 138 | dztop = vstokes(ig,l)* ptimestep |
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| 139 | Ep=0 |
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| 140 | k=0 |
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| 141 | |
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| 142 | c ************************************************************** |
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| 143 | c Simple Method |
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| 144 | w(ig,l) = |
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| 145 | & (1- exp(-dztop*g/(r*pt(ig,l))))*pplev(ig,l) / g |
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| 146 | cc write(*,*) 'OK simple method l,w =', l, w(ig,l) |
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| 147 | cc write(*,*) 'OK simple method dztop =', dztop |
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| 148 | c ************************************************************** |
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| 149 | cccc Complex method : |
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| 150 | if (dztop.gt.epaisseur(ig,l)) then |
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| 151 | cccc Cas ou on "epuise" la couche l : On calcule le flux |
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| 152 | cccc Venant de dessus en tenant compte de la variation de Vstokes |
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| 153 | |
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| 154 | Ep= epaisseur(ig,l) |
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| 155 | Stra= traversee(ig,l) |
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| 156 | do while(dztop.gt.Ep.and.l+k+1.le.nlay) |
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| 157 | k=k+1 |
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| 158 | dztop= Ep + vstokes(ig,l+k)*(ptimestep -Stra) |
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| 159 | Ep = Ep + epaisseur(ig,l+k) |
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| 160 | Stra = Stra + traversee(ig,l+k) |
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| 161 | enddo |
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| 162 | Ep = Ep - epaisseur(ig,l+k) |
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| 163 | end if |
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| 164 | ptop=pplev(ig,l+k)*exp(-(dztop-Ep)*g/(r*pt(ig,l+k))) |
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| 165 | w(ig,l) = (pplev(ig,l) -Ptop)/g |
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| 166 | c |
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| 167 | cc write(*,*) 'OK new method l,w =', l, w(ig,l) |
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| 168 | cc write(*,*) 'OK new method dztop =', dztop |
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| 169 | cc if(l.eq.7)write(*,*)'l=7,k,pplev,Ptop',pplev(ig,l),Ptop |
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| 170 | cc if(l.eq.7)write(*,*)'l=7,dztop,Ep',dztop,Ep |
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| 171 | cc if(l.eq.6)write(*,*)'l=6,k, w',k, w(1,l) |
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| 172 | cc if(l.eq.7)write(*,*)'l=7,k, w',k, w(1,l) |
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| 173 | cc if(l.eq.8)write(*,*)'l=8,k, w',k, w(1,l) |
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| 174 | c ************************************************************** |
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| 175 | end do |
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| 176 | end do |
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| 177 | |
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| 178 | call vlz_fi(ngrid,pqi,2.,masse,w,wq) |
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| 179 | c write(*,*) ' newsed: wq(6), wq(7), q(6)', |
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| 180 | c & wq(1,6),wq(1,7),pqi(1,6) |
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| 181 | |
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| 182 | |
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| 183 | RETURN |
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| 184 | END |
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| 185 | |
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