1 | ! |
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2 | ! $Id: cond_evap_tstep_mod.F90 3677 2020-05-06 15:18:32Z acozic $ |
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3 | ! |
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4 | MODULE cond_evap_tstep_mod |
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5 | |
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6 | ! based on UPMC aerosol model by Slimane Bekki |
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7 | ! adapted for stratospheric sulfate aerosol in LMDZ by Christoph Kleinschmitt |
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8 | |
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9 | CONTAINS |
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10 | |
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11 | SUBROUTINE condens_evapor_rate(R2SO4G,t_seri,pplay,ACTSO4,R2SO4, & |
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12 | & DENSO4,f_r_wet,RRSI,Vbin,FL,ASO4,DNDR) |
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13 | ! |
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14 | ! INPUT: |
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15 | ! R2SO4: aerosol H2SO4 weight fraction (percent) |
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16 | ! ACTSO4: H2SO4 activity |
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17 | ! R2SO4G: number density of gaseous H2SO4 [molecules/cm3] |
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18 | ! t_seri: temperature (K) |
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19 | ! DENSO4: aerosol density (gr/cm3) |
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20 | |
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21 | USE aerophys |
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22 | USE infotrac_phy |
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23 | USE YOMCST, ONLY : RPI |
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24 | |
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25 | IMPLICIT NONE |
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26 | |
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27 | ! input variables |
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28 | REAL R2SO4G !H2SO4 number density [molecules/cm3] |
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29 | REAL t_seri |
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30 | REAL pplay |
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31 | REAL ACTSO4 |
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32 | REAL R2SO4 |
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33 | REAL DENSO4 |
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34 | REAL f_r_wet |
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35 | REAL RRSI(nbtr_bin) |
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36 | REAL Vbin(nbtr_bin) |
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37 | |
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38 | ! output variables |
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39 | REAL FL(nbtr_bin) |
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40 | REAL ASO4(nbtr_bin) |
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41 | REAL DNDR(nbtr_bin) |
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42 | |
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43 | ! local variables |
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44 | INTEGER IK |
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45 | REAL ALPHA,CST |
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46 | REAL WH2,RP,VTK,AA,FL1,RKNUD |
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47 | REAL DND |
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48 | REAL ATOT,AH2O |
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49 | REAL RRSI_wet(nbtr_bin) |
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50 | REAL Vbin_wet(nbtr_bin) |
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51 | REAL MH2SO4,MH2O,BOLZ,FPATH |
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52 | |
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53 | ! /// MOLEC CONDENSATION GROWTH (DUE TO CHANGES IN H2SO4 AND SO H2O) |
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54 | ! ------------------------------------------------------------------ |
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55 | ! EXCEPT CN |
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56 | ! RK:H2SO4 WEIGHT PERCENT DOESN'T CHANGE |
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57 | ! BE CAREFUL,H2SO4 WEIGHT PERCENTAGE |
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58 | |
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59 | ! WEIGHT OF 1 MOLEC IN G |
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60 | MH2O =1000.*mH2Omol !18.016*1.66E-24 |
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61 | MH2SO4=1000.*mH2SO4mol !98.082*1.66E-24 |
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62 | ! BOLTZMANN CONSTANTE IN DYN.CM/K |
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63 | BOLZ =1.381E-16 |
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64 | ! MOLECULAR ACCOMODATION OF H2SO4 |
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65 | ! raes and van dingen |
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66 | ALPHA =0.1 |
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67 | ! FPLAIR=(2.281238E-5)*TAIR/PAIR |
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68 | ! 1.E2 (m to cm), |
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69 | CST=1.E2*2.281238E-5 |
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70 | |
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71 | ! compute local wet particle radius and volume |
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72 | RRSI_wet(:)=RRSI(:)*f_r_wet |
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73 | Vbin_wet(:)=Vbin(:)*f_r_wet**3 |
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74 | |
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75 | ! Pruppa and Klett |
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76 | FPATH=CST*t_seri/pplay |
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77 | |
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78 | |
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79 | ! H2SO4 mass fraction in aerosol |
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80 | WH2=R2SO4*1.0E-2 |
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81 | IF(WH2.EQ.0.0) RETURN |
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82 | ! ACTIVITY COEFFICIENT(SEE GIAUQUE,1951) |
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83 | ! AYERS ET AL (1980) |
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84 | ! (MU-MU0) |
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85 | RP=-10156.0/t_seri +16.259-(ACTSO4*4.184)/(8.31441*t_seri) |
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86 | ! DROPLET H2SO4 PRESSURE IN DYN.CM-2 |
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87 | RP=EXP(RP)*1.01325E6/0.086 |
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88 | ! RP=EXP(RP)*1.01325E6 |
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89 | ! H2SO4 NUMBER DENSITY NEAR DROPLET |
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90 | ! R=8.31E7 DYN.CM.MOL-1*K-1 |
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91 | ! R/AVOGADRO NUMBER=DYN.CM.MOLEC-1*K-1 |
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92 | DND=RP*6.02E23/(8.31E7*t_seri) |
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93 | ! MEAN KINETIC VELOCITY |
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94 | ! DYN*CM*K/(K*GR)=(CM/SEC2)*CM |
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95 | ! IN CM/SEC |
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96 | VTK=SQRT(8.0*BOLZ*t_seri/(RPI*MH2SO4)) |
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97 | ! KELVIN EFFECT FACTOR |
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98 | !CK 20160613: bug fix, removed factor 250 (from original code by S. Bekki) |
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99 | ! AA =2.0*MH2O*72.0/(DENSO4*BOLZ*t_seri*250.0) |
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100 | AA =2.0*MH2O*72.0/(DENSO4*BOLZ*t_seri) |
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101 | |
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102 | ! Loop on bin radius (RRSI in cm) |
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103 | DO IK=1,nbtr_bin |
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104 | ! KELVIN EFFECT |
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105 | DNDR(IK) =DND*EXP(AA/RRSI_wet(IK)) |
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106 | |
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107 | FL1=RPI*ALPHA*VTK*(R2SO4G-DNDR(IK)) |
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108 | |
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109 | ! TURCO(1979) FOR HNO3:ALH2SO4 CONDENSATION= ALH2SO4 EVAPORATION |
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110 | ! RPI*R2*VTK IS EQUIVALENT TO DIFFUSION COEFFICIENT |
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111 | ! EXTENSION OF THE RELATION FOR DIFFUSION KINETICS |
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112 | ! KNUDSEN NUMBER FPATH/RRSI |
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113 | ! NEW VERSION (SEE NOTES) |
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114 | RKNUD=FPATH/RRSI_wet(IK) |
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115 | ! SENFELD |
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116 | FL(IK)=FL1*RRSI_wet(IK)**2*( 1.0 +RKNUD ) & |
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117 | & /( 1.0 +ALPHA/(2.0*RKNUD) +RKNUD ) |
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118 | ! TURCO |
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119 | ! RL= (4.0/3.0 +0.71/RKNUD)/(1.0+1.0/RKNUD) |
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120 | ! * +4.0*(1.0-ALPHA)/(3.0*ALPHA) |
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121 | ! FL=FL1*RRSI(IK)*RRSI(IK) |
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122 | ! * /( (3.0*ALPHA/4.0)*(1.0/RKNUD+RL*ALPHA) ) |
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123 | |
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124 | ! INITIAL NUMBER OF H2SO4 MOLEC OF 1 DROPLET |
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125 | ATOT=4.0*RPI*DENSO4*(RRSI_wet(IK)**3)/3.0 !attention: g and cm |
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126 | ASO4(IK)=WH2*ATOT/MH2SO4 !attention: g |
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127 | ! ATOT=4.0*RPI*dens_aer(I,J)/1000.*(RRSI(IK)**3)/3.0 |
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128 | ! ASO4=mfrac_H2SO4*ATOT/MH2SO4 |
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129 | ! INITIAL NUMBER OF H2O MOLEC OF 1 DROPLET |
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130 | AH2O=(1.0-WH2)*ATOT/MH2O !attention: g |
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131 | |
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132 | ! CHANGE OF THE NUMBER OF H2SO4 MOLEC OF 1 DROPLET DURING DT |
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133 | ! IT IS FOR KEM BUT THERE ARE OTHER WAYS |
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134 | |
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135 | ENDDO !loop over bins |
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136 | |
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137 | END SUBROUTINE condens_evapor_rate |
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138 | |
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139 | !******************************************************************** |
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140 | SUBROUTINE cond_evap_part(dt,FL,ASO4,f_r_wet,RRSI,Vbin,tr_seri) |
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141 | |
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142 | USE aerophys |
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143 | USE infotrac_phy |
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144 | USE YOMCST, ONLY : RPI |
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145 | |
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146 | IMPLICIT NONE |
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147 | |
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148 | ! input variables |
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149 | REAL dt |
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150 | REAL FL(nbtr_bin) |
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151 | REAL ASO4(nbtr_bin) |
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152 | REAL f_r_wet |
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153 | REAL RRSI(nbtr_bin) |
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154 | REAL Vbin(nbtr_bin) |
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155 | |
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156 | ! output variables |
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157 | REAL tr_seri(nbtr) |
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158 | |
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159 | ! local variables |
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160 | REAL tr_seri_new(nbtr) |
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161 | INTEGER IK,JK,k |
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162 | REAL Vnew |
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163 | REAL RRSI_wet(nbtr_bin) |
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164 | REAL Vbin_wet(nbtr_bin) |
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165 | REAL sum_IK(nbtr_bin) |
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166 | REAL ff(nbtr_bin,nbtr_bin) |
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167 | |
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168 | tr_seri_new(:)=tr_seri(:) |
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169 | |
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170 | ! compute local wet particle radius and volume |
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171 | RRSI_wet(:)=RRSI(:)*f_r_wet |
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172 | Vbin_wet(:)=Vbin(:)*f_r_wet**3 *1.e6 !Vbin_wet in cm3 (as Vnew) |
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173 | |
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174 | ! compute distribution factor for particles of intermediate size (from Jacobson 1994, equation 13) |
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175 | DO IK=1,nbtr_bin |
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176 | Vnew=4.0*RPI*(RRSI_wet(IK)**3)/3.0*(1.+FL(IK)*dt/ASO4(IK)) |
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177 | ff(IK,:)=0.0 |
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178 | DO k=1, nbtr_bin |
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179 | IF (k.LE.(nbtr_bin-1)) THEN |
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180 | IF (Vbin_wet(k).LE.Vnew.AND.Vnew.LT.Vbin_wet(k+1)) THEN |
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181 | ff(IK,k)= Vbin_wet(k)/Vnew*(Vbin_wet(k+1)-Vnew)/(Vbin_wet(k+1)-Vbin_wet(k)) |
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182 | ENDIF |
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183 | ENDIF |
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184 | IF (k.EQ.1.AND.Vnew.LE.Vbin_wet(k)) THEN |
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185 | ff(IK,k)= 1. |
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186 | ENDIF |
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187 | IF (k.GT.1) THEN |
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188 | IF (Vbin_wet(k-1).LT.Vnew.AND.Vnew.LT.Vbin_wet(k)) THEN |
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189 | ff(IK,k)= 1.-ff(IK,k-1) |
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190 | ENDIF |
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191 | ENDIF |
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192 | IF (k.EQ.nbtr_bin.AND.Vnew.GE.Vbin_wet(k)) THEN |
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193 | ff(IK,k)= 1. |
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194 | ENDIF |
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195 | ENDDO |
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196 | ! correction of ff for volume conservation |
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197 | DO k=1, nbtr_bin |
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198 | ff(IK,k)=ff(IK,k)*Vnew/Vbin_wet(k) |
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199 | ENDDO |
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200 | ENDDO !loop over bins |
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201 | |
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202 | DO IK=1, nbtr_bin |
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203 | sum_IK(IK)=0.0 |
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204 | DO JK=1, nbtr_bin |
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205 | sum_IK(IK)=sum_IK(IK)+tr_seri(JK+nbtr_sulgas)*ff(JK,IK) |
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206 | ENDDO |
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207 | ! compute new particle concentrations |
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208 | tr_seri_new(IK+nbtr_sulgas)=sum_IK(IK) |
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209 | ENDDO |
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210 | |
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211 | tr_seri(:)=tr_seri_new(:) |
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212 | |
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213 | END SUBROUTINE cond_evap_part |
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214 | |
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215 | END MODULE cond_evap_tstep_mod |
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