| 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,nlayermx) |
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| 50 | real vstokes(ngrid,nlayermx) |
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| 51 | real w(ngrid,nlayermx) |
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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,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 | RETURN |
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| 198 | END |
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