1 | ! path: $Source$ |
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2 | ! author: $Author: miacono $ |
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3 | ! revision: $Revision: 23308 $ |
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4 | ! created: $Date: 2013-12-27 17:23:51 -0500 (Fri, 27 Dec 2013) $ |
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5 | |
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6 | module rrtmg_sw_cldprop |
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7 | |
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8 | ! -------------------------------------------------------------------------- |
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9 | ! | | |
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10 | ! | Copyright 2002-2009, Atmospheric & Environmental Research, Inc. (AER). | |
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11 | ! | This software may be used, copied, or redistributed as long as it is | |
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12 | ! | not sold and this copyright notice is reproduced on each copy made. | |
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13 | ! | This model is provided as is without any express or implied warranties. | |
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14 | ! | (http://www.rtweb.aer.com/) | |
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15 | ! | | |
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16 | ! -------------------------------------------------------------------------- |
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17 | |
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18 | ! ------- Modules ------- |
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19 | |
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20 | use parkind, only : im => kind_im, rb => kind_rb |
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21 | use parrrsw, only : nbndsw, jpband, jpb1, jpb2 |
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22 | use rrsw_cld, only : extliq1, ssaliq1, asyliq1, & |
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23 | extice2, ssaice2, asyice2, & |
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24 | extice3, ssaice3, asyice3, fdlice3, & |
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25 | abari, bbari, cbari, dbari, ebari, fbari |
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26 | use rrsw_wvn, only : wavenum1, wavenum2 |
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27 | use rrsw_vsn, only : hvrcld, hnamcld |
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28 | |
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29 | implicit none |
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30 | |
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31 | contains |
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32 | |
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33 | ! ---------------------------------------------------------------------------- |
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34 | subroutine cldprop_sw(nlayers, inflag, iceflag, liqflag, cldfrac, & |
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35 | tauc, ssac, asmc, fsfc, ciwp, clwp, rei, rel, & |
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36 | taucldorig, taucloud, ssacloud, asmcloud) |
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37 | ! ---------------------------------------------------------------------------- |
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38 | |
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39 | ! Purpose: Compute the cloud optical properties for each cloudy layer. |
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40 | ! Note: Only inflag = 0 and inflag=2/liqflag=1/iceflag=1,2,3 are available; |
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41 | ! (Hu & Stamnes, Ebert and Curry, Key, and Fu) are implemented. |
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42 | |
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43 | ! ------- Input ------- |
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44 | |
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45 | integer(kind=im), intent(in) :: nlayers ! total number of layers |
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46 | integer(kind=im), intent(in) :: inflag ! see definitions |
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47 | integer(kind=im), intent(in) :: iceflag ! see definitions |
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48 | integer(kind=im), intent(in) :: liqflag ! see definitions |
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49 | |
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50 | real(kind=rb), intent(in) :: cldfrac(:) ! cloud fraction |
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51 | ! Dimensions: (nlayers) |
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52 | real(kind=rb), intent(in) :: ciwp(:) ! cloud ice water path |
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53 | ! Dimensions: (nlayers) |
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54 | real(kind=rb), intent(in) :: clwp(:) ! cloud liquid water path |
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55 | ! Dimensions: (nlayers) |
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56 | real(kind=rb), intent(in) :: rei(:) ! cloud ice particle effective size (microns) |
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57 | ! Dimensions: (nlayers) |
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58 | ! specific definition of rei depends on setting of iceflag: |
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59 | ! iceflag = 0: (inactive) |
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60 | ! |
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61 | ! iceflag = 1: ice effective radius, r_ec, (Ebert and Curry, 1992), |
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62 | ! r_ec range is limited to 13.0 to 130.0 microns |
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63 | ! iceflag = 2: ice effective radius, r_k, (Key, Streamer Ref. Manual, 1996) |
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64 | ! r_k range is limited to 5.0 to 131.0 microns |
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65 | ! iceflag = 3: generalized effective size, dge, (Fu, 1996), |
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66 | ! dge range is limited to 5.0 to 140.0 microns |
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67 | ! [dge = 1.0315 * r_ec] |
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68 | real(kind=rb), intent(in) :: rel(:) ! cloud liquid particle effective radius (microns) |
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69 | ! Dimensions: (nlayers) |
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70 | real(kind=rb), intent(in) :: tauc(:,:) ! cloud optical depth |
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71 | ! Dimensions: (nbndsw,nlayers) |
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72 | real(kind=rb), intent(in) :: ssac(:,:) ! single scattering albedo |
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73 | ! Dimensions: (nbndsw,nlayers) |
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74 | real(kind=rb), intent(in) :: asmc(:,:) ! asymmetry parameter |
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75 | ! Dimensions: (nbndsw,nlayers) |
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76 | real(kind=rb), intent(in) :: fsfc(:,:) ! forward scattering fraction |
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77 | ! Dimensions: (nbndsw,nlayers) |
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78 | |
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79 | ! ------- Output ------- |
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80 | |
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81 | real(kind=rb), intent(out) :: taucloud(:,:) ! cloud optical depth (delta scaled) |
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82 | ! Dimensions: (nlayers,jpband) |
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83 | real(kind=rb), intent(out) :: taucldorig(:,:) ! cloud optical depth (non-delta scaled) |
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84 | ! Dimensions: (nlayers,jpband) |
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85 | real(kind=rb), intent(out) :: ssacloud(:,:) ! single scattering albedo (delta scaled) |
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86 | ! Dimensions: (nlayers,jpband) |
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87 | real(kind=rb), intent(out) :: asmcloud(:,:) ! asymmetry parameter (delta scaled) |
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88 | ! Dimensions: (nlayers,jpband) |
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89 | |
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90 | ! ------- Local ------- |
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91 | |
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92 | ! integer(kind=im) :: ncbands |
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93 | integer(kind=im) :: ib, ib1, ib2, lay, istr, index, icx |
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94 | |
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95 | real(kind=rb), parameter :: eps = 1.e-06_rb ! epsilon |
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96 | real(kind=rb), parameter :: cldmin = 1.e-20_rb ! minimum value for cloud quantities |
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97 | real(kind=rb) :: cwp ! total cloud water path |
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98 | real(kind=rb) :: radliq ! cloud liquid droplet radius (microns) |
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99 | real(kind=rb) :: radice ! cloud ice effective size (microns) |
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100 | real(kind=rb) :: factor |
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101 | real(kind=rb) :: fint |
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102 | real(kind=rb) :: tauctot(nlayers) ! band integrated cloud optical depth |
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103 | |
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104 | real(kind=rb) :: taucldorig_a, ssacloud_a, taucloud_a, ffp, ffp1, ffpssa |
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105 | real(kind=rb) :: tauiceorig, scatice, ssaice, tauice, tauliqorig, scatliq, ssaliq, tauliq |
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106 | |
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107 | real(kind=rb) :: fdelta(jpb1:jpb2) |
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108 | real(kind=rb) :: extcoice(jpb1:jpb2), gice(jpb1:jpb2) |
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109 | real(kind=rb) :: ssacoice(jpb1:jpb2), forwice(jpb1:jpb2) |
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110 | real(kind=rb) :: extcoliq(jpb1:jpb2), gliq(jpb1:jpb2) |
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111 | real(kind=rb) :: ssacoliq(jpb1:jpb2), forwliq(jpb1:jpb2) |
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112 | |
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113 | ! Initialize |
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114 | |
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115 | hvrcld = '$Revision: 23308 $' |
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116 | |
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117 | ! ncbands = 29 |
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118 | ib1 = jpb1 |
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119 | ib2 = jpb2 |
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120 | tauctot(:) = 0._rb |
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121 | |
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122 | do lay = 1, nlayers |
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123 | do ib = ib1 , ib2 |
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124 | taucldorig(lay,ib) = tauc(ib-15,lay) |
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125 | taucloud(lay,ib) = 0.0_rb |
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126 | ssacloud(lay,ib) = 1.0_rb |
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127 | asmcloud(lay,ib) = 0.0_rb |
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128 | tauctot(lay) = tauctot(lay) + tauc(ib-15,lay) |
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129 | enddo |
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130 | enddo |
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131 | |
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132 | ! Main layer loop |
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133 | do lay = 1, nlayers |
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134 | |
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135 | cwp = ciwp(lay) + clwp(lay) |
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136 | if (cldfrac(lay) .ge. cldmin .and. & |
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137 | (cwp .ge. cldmin .or. tauctot(lay) .ge. cldmin)) then |
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138 | |
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139 | ! (inflag=0): Cloud optical properties input directly |
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140 | ! Cloud optical properties already defined in tauc, ssac, asmc are unscaled; |
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141 | ! Apply delta-M scaling here |
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142 | if (inflag .eq. 0) then |
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143 | |
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144 | do ib = ib1 , ib2 |
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145 | taucldorig_a = tauc(ib-15,lay) |
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146 | ffp = fsfc(ib-15,lay) |
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147 | ffp1 = 1.0_rb - ffp |
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148 | ffpssa = 1.0_rb - ffp * ssac(ib-15,lay) |
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149 | ssacloud_a = ffp1 * ssac(ib-15,lay) / ffpssa |
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150 | taucloud_a = ffpssa * taucldorig_a |
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151 | |
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152 | taucldorig(lay,ib) = taucldorig_a |
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153 | ssacloud(lay,ib) = ssacloud_a |
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154 | taucloud(lay,ib) = taucloud_a |
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155 | asmcloud(lay,ib) = (asmc(ib-15,lay) - ffp) / (ffp1) |
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156 | enddo |
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157 | |
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158 | ! (inflag=2): Separate treatement of ice clouds and water clouds. |
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159 | elseif (inflag .eq. 2) then |
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160 | radice = rei(lay) |
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161 | |
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162 | ! Calculation of absorption coefficients due to ice clouds. |
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163 | if (ciwp(lay) .eq. 0.0_rb) then |
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164 | do ib = ib1 , ib2 |
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165 | extcoice(ib) = 0.0_rb |
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166 | ssacoice(ib) = 0.0_rb |
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167 | gice(ib) = 0.0_rb |
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168 | forwice(ib) = 0.0_rb |
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169 | enddo |
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170 | |
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171 | ! (iceflag = 1): |
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172 | ! Note: This option uses Ebert and Curry approach for all particle sizes similar to |
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173 | ! CAM3 implementation, though this is somewhat ineffective for large ice particles |
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174 | elseif (iceflag .eq. 1) then |
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175 | if (radice .lt. 13.0_rb .or. radice .gt. 130._rb) stop & |
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176 | 'ICE RADIUS OUT OF BOUNDS' |
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177 | do ib = ib1, ib2 |
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178 | if (wavenum2(ib) .gt. 1.43e04_rb) then |
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179 | icx = 1 |
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180 | elseif (wavenum2(ib) .gt. 7.7e03_rb) then |
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181 | icx = 2 |
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182 | elseif (wavenum2(ib) .gt. 5.3e03_rb) then |
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183 | icx = 3 |
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184 | elseif (wavenum2(ib) .gt. 4.0e03_rb) then |
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185 | icx = 4 |
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186 | elseif (wavenum2(ib) .ge. 2.5e03_rb) then |
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187 | icx = 5 |
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188 | endif |
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189 | extcoice(ib) = abari(icx) + bbari(icx)/radice |
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190 | ssacoice(ib) = 1._rb - cbari(icx) - dbari(icx) * radice |
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191 | gice(ib) = ebari(icx) + fbari(icx) * radice |
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192 | |
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193 | ! Check to ensure upper limit of gice is within physical limits for large particles |
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194 | if (gice(ib) .ge. 1.0_rb) gice(ib) = 1.0_rb - eps |
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195 | forwice(ib) = gice(ib)*gice(ib) |
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196 | ! Check to ensure all calculated quantities are within physical limits. |
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197 | if (extcoice(ib) .lt. 0.0_rb) stop 'ICE EXTINCTION LESS THAN 0.0' |
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198 | if (ssacoice(ib) .gt. 1.0_rb) stop 'ICE SSA GRTR THAN 1.0' |
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199 | if (ssacoice(ib) .lt. 0.0_rb) stop 'ICE SSA LESS THAN 0.0' |
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200 | if (gice(ib) .gt. 1.0_rb) stop 'ICE ASYM GRTR THAN 1.0' |
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201 | if (gice(ib) .lt. 0.0_rb) stop 'ICE ASYM LESS THAN 0.0' |
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202 | enddo |
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203 | |
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204 | ! For iceflag=2 option, ice particle effective radius is limited to 5.0 to 131.0 microns |
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205 | |
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206 | elseif (iceflag .eq. 2) then |
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207 | if (radice .lt. 5.0_rb .or. radice .gt. 131.0_rb) stop 'ICE RADIUS OUT OF BOUNDS' |
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208 | factor = (radice - 2._rb)/3._rb |
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209 | index = int(factor) |
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210 | if (index .eq. 43) index = 42 |
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211 | fint = factor - real(index,kind=rb) |
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212 | do ib = ib1, ib2 |
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213 | extcoice(ib) = extice2(index,ib) + fint * & |
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214 | (extice2(index+1,ib) - extice2(index,ib)) |
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215 | ssacoice(ib) = ssaice2(index,ib) + fint * & |
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216 | (ssaice2(index+1,ib) - ssaice2(index,ib)) |
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217 | gice(ib) = asyice2(index,ib) + fint * & |
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218 | (asyice2(index+1,ib) - asyice2(index,ib)) |
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219 | forwice(ib) = gice(ib)*gice(ib) |
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220 | ! Check to ensure all calculated quantities are within physical limits. |
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221 | if (extcoice(ib) .lt. 0.0_rb) stop 'ICE EXTINCTION LESS THAN 0.0' |
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222 | if (ssacoice(ib) .gt. 1.0_rb) stop 'ICE SSA GRTR THAN 1.0' |
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223 | if (ssacoice(ib) .lt. 0.0_rb) stop 'ICE SSA LESS THAN 0.0' |
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224 | if (gice(ib) .gt. 1.0_rb) stop 'ICE ASYM GRTR THAN 1.0' |
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225 | if (gice(ib) .lt. 0.0_rb) stop 'ICE ASYM LESS THAN 0.0' |
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226 | enddo |
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227 | |
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228 | ! For iceflag=3 option, ice particle generalized effective size is limited to 5.0 to 140.0 microns |
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229 | |
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230 | elseif (iceflag .eq. 3) then |
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231 | if (radice .lt. 5.0_rb .or. radice .gt. 140.0_rb) stop 'ICE GENERALIZED EFFECTIVE SIZE OUT OF BOUNDS' |
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232 | factor = (radice - 2._rb)/3._rb |
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233 | index = int(factor) |
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234 | if (index .eq. 46) index = 45 |
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235 | fint = factor - real(index,kind=rb) |
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236 | do ib = ib1 , ib2 |
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237 | extcoice(ib) = extice3(index,ib) + fint * & |
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238 | (extice3(index+1,ib) - extice3(index,ib)) |
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239 | ssacoice(ib) = ssaice3(index,ib) + fint * & |
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240 | (ssaice3(index+1,ib) - ssaice3(index,ib)) |
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241 | gice(ib) = asyice3(index,ib) + fint * & |
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242 | (asyice3(index+1,ib) - asyice3(index,ib)) |
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243 | fdelta(ib) = fdlice3(index,ib) + fint * & |
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244 | (fdlice3(index+1,ib) - fdlice3(index,ib)) |
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245 | if (fdelta(ib) .lt. 0.0_rb) stop 'FDELTA LESS THAN 0.0' |
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246 | if (fdelta(ib) .gt. 1.0_rb) stop 'FDELTA GT THAN 1.0' |
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247 | forwice(ib) = fdelta(ib) + 0.5_rb / ssacoice(ib) |
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248 | ! See Fu 1996 p. 2067 |
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249 | if (forwice(ib) .gt. gice(ib)) forwice(ib) = gice(ib) |
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250 | ! Check to ensure all calculated quantities are within physical limits. |
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251 | if (extcoice(ib) .lt. 0.0_rb) stop 'ICE EXTINCTION LESS THAN 0.0' |
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252 | if (ssacoice(ib) .gt. 1.0_rb) stop 'ICE SSA GRTR THAN 1.0' |
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253 | if (ssacoice(ib) .lt. 0.0_rb) stop 'ICE SSA LESS THAN 0.0' |
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254 | if (gice(ib) .gt. 1.0_rb) stop 'ICE ASYM GRTR THAN 1.0' |
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255 | if (gice(ib) .lt. 0.0_rb) stop 'ICE ASYM LESS THAN 0.0' |
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256 | enddo |
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257 | |
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258 | endif |
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259 | |
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260 | ! Calculation of absorption coefficients due to water clouds. |
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261 | if (clwp(lay) .eq. 0.0_rb) then |
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262 | do ib = ib1 , ib2 |
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263 | extcoliq(ib) = 0.0_rb |
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264 | ssacoliq(ib) = 0.0_rb |
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265 | gliq(ib) = 0.0_rb |
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266 | forwliq(ib) = 0.0_rb |
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267 | enddo |
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268 | |
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269 | elseif (liqflag .eq. 1) then |
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270 | radliq = rel(lay) |
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271 | if (radliq .lt. 2.5_rb .or. radliq .gt. 60._rb) stop & |
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272 | 'LIQUID EFFECTIVE RADIUS OUT OF BOUNDS' |
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273 | index = int(radliq - 1.5_rb) |
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274 | if (index .eq. 0) index = 1 |
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275 | if (index .eq. 58) index = 57 |
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276 | fint = radliq - 1.5_rb - real(index,kind=rb) |
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277 | do ib = ib1 , ib2 |
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278 | extcoliq(ib) = extliq1(index,ib) + fint * & |
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279 | (extliq1(index+1,ib) - extliq1(index,ib)) |
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280 | ssacoliq(ib) = ssaliq1(index,ib) + fint * & |
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281 | (ssaliq1(index+1,ib) - ssaliq1(index,ib)) |
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282 | if (fint .lt. 0._rb .and. ssacoliq(ib) .gt. 1._rb) & |
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283 | ssacoliq(ib) = ssaliq1(index,ib) |
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284 | gliq(ib) = asyliq1(index,ib) + fint * & |
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285 | (asyliq1(index+1,ib) - asyliq1(index,ib)) |
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286 | forwliq(ib) = gliq(ib)*gliq(ib) |
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287 | ! Check to ensure all calculated quantities are within physical limits. |
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288 | if (extcoliq(ib) .lt. 0.0_rb) stop 'LIQUID EXTINCTION LESS THAN 0.0' |
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289 | if (ssacoliq(ib) .gt. 1.0_rb) stop 'LIQUID SSA GRTR THAN 1.0' |
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290 | if (ssacoliq(ib) .lt. 0.0_rb) stop 'LIQUID SSA LESS THAN 0.0' |
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291 | if (gliq(ib) .gt. 1.0_rb) stop 'LIQUID ASYM GRTR THAN 1.0' |
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292 | if (gliq(ib) .lt. 0.0_rb) stop 'LIQUID ASYM LESS THAN 0.0' |
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293 | enddo |
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294 | endif |
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295 | |
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296 | do ib = ib1 , ib2 |
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297 | tauliqorig = clwp(lay) * extcoliq(ib) |
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298 | tauiceorig = ciwp(lay) * extcoice(ib) |
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299 | taucldorig(lay,ib) = tauliqorig + tauiceorig |
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300 | |
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301 | ssaliq = ssacoliq(ib) * (1.0_rb - forwliq(ib)) / & |
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302 | (1.0_rb - forwliq(ib) * ssacoliq(ib)) |
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303 | tauliq = (1.0_rb - forwliq(ib) * ssacoliq(ib)) * tauliqorig |
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304 | ssaice = ssacoice(ib) * (1.0_rb - forwice(ib)) / & |
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305 | (1.0_rb - forwice(ib) * ssacoice(ib)) |
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306 | tauice = (1.0_rb - forwice(ib) * ssacoice(ib)) * tauiceorig |
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307 | |
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308 | scatliq = ssaliq * tauliq |
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309 | scatice = ssaice * tauice |
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310 | |
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311 | taucloud(lay,ib) = tauliq + tauice |
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312 | |
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313 | ! Ensure non-zero taucmc and scatice |
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314 | if (taucloud(lay,ib).eq.0.0_rb) taucloud(lay,ib) = cldmin |
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315 | if (scatice.eq.0.0_rb) scatice = cldmin |
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316 | |
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317 | ssacloud(lay,ib) = (scatliq + scatice) / taucloud(lay,ib) |
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318 | |
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319 | if (iceflag .eq. 3) then |
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320 | ! In accordance with the 1996 Fu paper, equation A.3, |
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321 | ! the moments for ice were calculated depending on whether using spheres |
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322 | ! or hexagonal ice crystals. |
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323 | istr = 1 |
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324 | asmcloud(lay,ib) = (1.0_rb/(scatliq+scatice)) * & |
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325 | (scatliq*(gliq(ib)**istr - forwliq(ib)) / & |
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326 | (1.0_rb - forwliq(ib)) + scatice * ((gice(ib)-forwice(ib)) / & |
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327 | (1.0_rb - forwice(ib)))**istr) |
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328 | else |
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329 | ! This code is the standard method for delta-m scaling. |
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330 | istr = 1 |
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331 | asmcloud(lay,ib) = (scatliq * & |
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332 | (gliq(ib)**istr - forwliq(ib)) / & |
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333 | (1.0_rb - forwliq(ib)) + scatice * (gice(ib)**istr - forwice(ib)) / & |
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334 | (1.0_rb - forwice(ib)))/(scatliq + scatice) |
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335 | endif |
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336 | |
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337 | enddo |
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338 | |
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339 | endif |
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340 | |
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341 | endif |
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342 | |
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343 | ! End layer loop |
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344 | enddo |
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345 | |
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346 | end subroutine cldprop_sw |
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347 | |
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348 | end module rrtmg_sw_cldprop |
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349 | |
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350 | |
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