1 | ! |
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2 | ! $Id: friction.F 1907 2013-11-26 13:10:46Z adurocher $ |
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3 | ! |
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4 | c======================================================================= |
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5 | SUBROUTINE friction(ucov,vcov,pdt) |
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6 | |
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7 | USE control_mod |
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8 | #ifdef CPP_IOIPSL |
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9 | USE IOIPSL |
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10 | #else |
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11 | ! if not using IOIPSL, we still need to use (a local version of) getin |
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12 | USE ioipsl_getincom |
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13 | #endif |
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14 | |
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15 | IMPLICIT NONE |
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16 | |
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17 | !======================================================================= |
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18 | ! |
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19 | ! Friction for the Newtonian case: |
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20 | ! -------------------------------- |
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21 | ! 2 possibilities (depending on flag 'friction_type' |
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22 | ! friction_type=0 : A friction that is only applied to the lowermost |
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23 | ! atmospheric layer |
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24 | ! friction_type=1 : Friction applied on all atmospheric layer (but |
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25 | ! (default) with stronger magnitude near the surface; see |
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26 | ! iniacademic.F) |
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27 | !======================================================================= |
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28 | |
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29 | #include "dimensions.h" |
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30 | #include "paramet.h" |
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31 | #include "comgeom2.h" |
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32 | #include "comconst.h" |
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33 | #include "iniprint.h" |
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34 | #include "academic.h" |
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35 | |
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36 | ! arguments: |
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37 | REAL,INTENT(out) :: ucov( iip1,jjp1,llm ) |
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38 | REAL,INTENT(out) :: vcov( iip1,jjm,llm ) |
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39 | REAL,INTENT(in) :: pdt ! time step |
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40 | |
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41 | ! local variables: |
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42 | |
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43 | REAL modv(iip1,jjp1),zco,zsi |
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44 | REAL vpn,vps,upoln,upols,vpols,vpoln |
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45 | REAL u2(iip1,jjp1),v2(iip1,jjm) |
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46 | INTEGER i,j,l |
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47 | REAL,PARAMETER :: cfric=1.e-5 |
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48 | LOGICAL,SAVE :: firstcall=.true. |
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49 | INTEGER,SAVE :: friction_type=1 |
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50 | CHARACTER(len=20) :: modname="friction" |
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51 | CHARACTER(len=80) :: abort_message |
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52 | |
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53 | IF (firstcall) THEN |
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54 | ! set friction type |
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55 | call getin("friction_type",friction_type) |
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56 | if ((friction_type.lt.0).or.(friction_type.gt.1)) then |
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57 | abort_message="wrong friction type" |
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58 | write(lunout,*)'Friction: wrong friction type',friction_type |
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59 | call abort_gcm(modname,abort_message,42) |
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60 | endif |
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61 | firstcall=.false. |
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62 | ENDIF |
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63 | |
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64 | if (friction_type.eq.0) then |
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65 | c calcul des composantes au carre du vent naturel |
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66 | do j=1,jjp1 |
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67 | do i=1,iip1 |
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68 | u2(i,j)=ucov(i,j,1)*ucov(i,j,1)*unscu2(i,j) |
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69 | enddo |
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70 | enddo |
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71 | do j=1,jjm |
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72 | do i=1,iip1 |
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73 | v2(i,j)=vcov(i,j,1)*vcov(i,j,1)*unscv2(i,j) |
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74 | enddo |
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75 | enddo |
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76 | |
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77 | c calcul du module de V en dehors des poles |
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78 | do j=2,jjm |
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79 | do i=2,iip1 |
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80 | modv(i,j)=sqrt(0.5*(u2(i-1,j)+u2(i,j)+v2(i,j-1)+v2(i,j))) |
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81 | enddo |
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82 | modv(1,j)=modv(iip1,j) |
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83 | enddo |
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84 | |
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85 | c les deux composantes du vent au pole sont obtenues comme |
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86 | c premiers modes de fourier de v pres du pole |
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87 | upoln=0. |
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88 | vpoln=0. |
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89 | upols=0. |
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90 | vpols=0. |
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91 | do i=2,iip1 |
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92 | zco=cos(rlonv(i))*(rlonu(i)-rlonu(i-1)) |
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93 | zsi=sin(rlonv(i))*(rlonu(i)-rlonu(i-1)) |
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94 | vpn=vcov(i,1,1)/cv(i,1) |
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95 | vps=vcov(i,jjm,1)/cv(i,jjm) |
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96 | upoln=upoln+zco*vpn |
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97 | vpoln=vpoln+zsi*vpn |
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98 | upols=upols+zco*vps |
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99 | vpols=vpols+zsi*vps |
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100 | enddo |
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101 | vpn=sqrt(upoln*upoln+vpoln*vpoln)/pi |
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102 | vps=sqrt(upols*upols+vpols*vpols)/pi |
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103 | do i=1,iip1 |
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104 | c modv(i,1)=vpn |
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105 | c modv(i,jjp1)=vps |
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106 | modv(i,1)=modv(i,2) |
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107 | modv(i,jjp1)=modv(i,jjm) |
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108 | enddo |
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109 | |
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110 | c calcul du frottement au sol. |
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111 | do j=2,jjm |
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112 | do i=1,iim |
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113 | ucov(i,j,1)=ucov(i,j,1) |
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114 | s -cfric*pdt*0.5*(modv(i+1,j)+modv(i,j))*ucov(i,j,1) |
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115 | enddo |
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116 | ucov(iip1,j,1)=ucov(1,j,1) |
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117 | enddo |
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118 | do j=1,jjm |
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119 | do i=1,iip1 |
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120 | vcov(i,j,1)=vcov(i,j,1) |
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121 | s -cfric*pdt*0.5*(modv(i,j+1)+modv(i,j))*vcov(i,j,1) |
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122 | enddo |
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123 | vcov(iip1,j,1)=vcov(1,j,1) |
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124 | enddo |
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125 | endif ! of if (friction_type.eq.0) |
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126 | |
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127 | if (friction_type.eq.1) then |
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128 | do l=1,llm |
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129 | ucov(:,:,l)=ucov(:,:,l)*(1.-pdt*kfrict(l)) |
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130 | vcov(:,:,l)=vcov(:,:,l)*(1.-pdt*kfrict(l)) |
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131 | enddo |
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132 | endif |
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133 | |
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134 | RETURN |
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135 | END |
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136 | |
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