[3526] | 1 | ! |
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| 2 | ! $Id: aer_sedimnt.F90 3677 2020-05-06 15:18:32Z emillour $ |
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| 3 | ! |
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[2690] | 4 | SUBROUTINE AER_SEDIMNT(pdtphys, t_seri, pplay, paprs, tr_seri, dens_aer) |
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| 5 | |
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| 6 | !**** *AER_SEDIMNT* - ROUTINE FOR PARAMETRIZATION OF AEROSOL SEDIMENTATION |
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| 7 | |
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| 8 | ! Christoph Kleinschmitt |
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| 9 | ! based on the sedimentation scheme of |
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| 10 | ! Olivier Boucher & Jean-Jacques Morcrette |
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| 11 | ! (following the ice sedimentation scheme of Adrian Tompkins) |
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| 12 | |
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| 13 | !** INTERFACE. |
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| 14 | ! ---------- |
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| 15 | ! *AER_SEDIMNT* IS CALLED FROM *traccoag_mod*. |
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| 16 | |
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| 17 | !----------------------------------------------------------------------- |
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| 18 | |
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[2752] | 19 | USE phys_local_var_mod, ONLY: mdw, budg_sed_part, DENSO4, f_r_wet, vsed_aer |
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[2690] | 20 | USE dimphy, ONLY : klon,klev |
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[3677] | 21 | USE infotrac_phy |
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[2690] | 22 | USE aerophys |
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| 23 | USE YOMCST |
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| 24 | |
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| 25 | IMPLICIT NONE |
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| 26 | |
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| 27 | !----------------------------------------------------------------------- |
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| 28 | |
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| 29 | ! transfer variables when calling this routine |
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| 30 | REAL,INTENT(IN) :: pdtphys ! Pas d'integration pour la physique (seconde) |
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| 31 | REAL,DIMENSION(klon,klev),INTENT(IN) :: t_seri ! Temperature |
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| 32 | REAL,DIMENSION(klon,klev),INTENT(IN) :: pplay ! pression pour le mileu de chaque couche (en Pa) |
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| 33 | REAL,DIMENSION(klon,klev+1),INTENT(IN) :: paprs ! pression pour chaque inter-couche (en Pa) |
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| 34 | REAL,DIMENSION(klon,klev,nbtr),INTENT(INOUT):: tr_seri ! Concentration Traceur [U/KgA] |
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| 35 | REAL,DIMENSION(klon,klev) :: dens_aer! density of aerosol particles [kg/m3 aerosol] with default H2SO4 mass |
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| 36 | |
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| 37 | ! local variables in sedimentation routine |
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| 38 | INTEGER :: JL,JK,nb |
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| 39 | REAL,DIMENSION(klon,klev) :: zvis ! dynamic viscosity of air [kg/(m*s)] |
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| 40 | REAL,DIMENSION(klon,klev) :: zlair ! mean free path of air [m] |
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| 41 | REAL :: ZRHO ! air density [kg/m^3] |
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| 42 | REAL :: ZGDP ! =g/dp=1/(rho*dz) |
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| 43 | REAL :: ZDTGDP ! =dt/(rho*dz) |
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| 44 | REAL,DIMENSION(klon,nbtr_bin) :: ZSEDFLX ! sedimentation flux of tracer [U/(m^2*s)] |
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| 45 | REAL,DIMENSION(nbtr_bin) :: ZAERONW ! tracer concentration at current time step [U/KgA] |
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| 46 | REAL,DIMENSION(klon,nbtr_bin) :: ZAERONWM1! tracer concentration at preceding time step [U/KgA] |
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| 47 | REAL,DIMENSION(klon,klev,nbtr_bin) :: ZVAER ! sedimentation velocity [m/s] |
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| 48 | REAL,DIMENSION(nbtr_bin) :: ZSOLAERS ! sedimentation flux arriving from above [U/(m^2*s)] |
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| 49 | REAL,DIMENSION(nbtr_bin) :: ZSOLAERB ! sedimentation flux leaving gridbox [U/(m^2*s)] |
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| 50 | REAL,DIMENSION(klon,klev) :: m_sulf |
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| 51 | |
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| 52 | ! dynamic viscosity of air (Pruppacher and Klett, 1978) [kg/(m*s)] |
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| 53 | WHERE (t_seri.GE.273.15) |
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| 54 | zvis=(1.718 + 0.0049*(t_seri-273.15))*1.E-5 |
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| 55 | ELSEWHERE |
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| 56 | zvis=(1.718 + 0.0049*(t_seri-273.15)-1.2E-05*(t_seri-273.15)**2)*1.E-5 |
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| 57 | END WHERE |
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| 58 | |
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| 59 | ! mean free path of air (Prupp. Klett) [m] |
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| 60 | zlair(:,:) = 0.066 *(1.01325E+5/pplay(:,:))*(t_seri(:,:)/293.15)*1.E-06 |
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| 61 | |
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| 62 | !--initialisations of variables carried out from one layer to the next layer |
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| 63 | !--actually not needed if (JK>1) test is on |
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| 64 | DO JL=1,klon |
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| 65 | DO nb=1,nbtr_bin |
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| 66 | ZSEDFLX(JL,nb)=0.0 |
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| 67 | ZAERONWM1(JL,nb)=0.0 |
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| 68 | ENDDO |
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| 69 | ENDDO |
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| 70 | |
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| 71 | !--from top to bottom (!) |
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| 72 | DO JK=klev,1,-1 |
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| 73 | DO JL=1,klon |
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| 74 | DO nb=1,nbtr_bin |
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| 75 | !--initialisations |
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| 76 | ZSOLAERS(nb)=0.0 |
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| 77 | ZSOLAERB(nb)=0.0 |
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| 78 | ZGDP=RG/(paprs(JL,JK)-paprs(JL,JK+1)) |
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| 79 | ZDTGDP=pdtphys*ZGDP |
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| 80 | |
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| 81 | ! source from above |
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| 82 | IF (JK<klev) THEN |
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| 83 | ZSEDFLX(JL,nb)=ZSEDFLX(JL,nb)*ZAERONWM1(JL,nb) |
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| 84 | ZSOLAERS(nb)=ZSOLAERS(nb)+ZSEDFLX(JL,nb)*ZDTGDP |
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| 85 | ENDIF |
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| 86 | |
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| 87 | ! sink to next layer |
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| 88 | ZRHO=pplay(JL,JK)/(RD*t_seri(JL,JK)) |
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| 89 | |
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| 90 | ! stokes-velocity with cunnigham slip- flow correction |
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| 91 | ZVAER(JL,JK,nb) = 2./9.*(DENSO4(JL,JK)*1000.-ZRHO)*RG/zvis(JL,JK)*(f_r_wet(JL,JK)*mdw(nb)/2.)**2.* & |
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| 92 | (1.+ 2.*zlair(JL,JK)/(f_r_wet(JL,JK)*mdw(nb))*(1.257+0.4*EXP(-0.55*f_r_wet(JL,JK)*mdw(nb)/zlair(JL,JK)))) |
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| 93 | |
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| 94 | ZSEDFLX(JL,nb)=ZVAER(JL,JK,nb)*ZRHO |
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| 95 | ZSOLAERB(nb)=ZSOLAERB(nb)+ZDTGDP*ZSEDFLX(JL,nb) |
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| 96 | |
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| 97 | !---implicit solver |
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| 98 | ZAERONW(nb)=(tr_seri(JL,JK,nb+nbtr_sulgas)+ZSOLAERS(nb))/(1.0+ZSOLAERB(nb)) |
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| 99 | |
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| 100 | !---new time-step AER variable needed for next layer |
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| 101 | ZAERONWM1(JL,nb)=ZAERONW(nb) |
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| 102 | |
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| 103 | tr_seri(JL,JK,nb+nbtr_sulgas)=ZAERONWM1(JL,nb) |
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| 104 | ENDDO |
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| 105 | ENDDO |
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| 106 | ENDDO |
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| 107 | |
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| 108 | !---sedimentation flux to the surface |
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| 109 | !---ZAERONWM1 now contains the surface concentration at the new timestep |
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| 110 | !---PFLUXAER in unit of xx m-2 s-1 |
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[2752] | 111 | budg_sed_part(:)=0.0 |
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[2690] | 112 | DO JL=1,klon |
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| 113 | ZRHO=pplay(JL,1)/(RD*t_seri(JL,1)) |
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| 114 | DO nb=1,nbtr_bin |
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[2752] | 115 | !compute budg_sed_part as sum over bins in kg(S)/m2/s |
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| 116 | budg_sed_part(JL)=budg_sed_part(JL)+ZRHO*ZAERONWM1(JL,nb)*ZVAER(JL,1,nb)*(mSatom/mH2SO4mol) & |
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[2690] | 117 | & *dens_aer_dry*4./3.*RPI*(mdw(nb)/2.)**3 |
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| 118 | ENDDO |
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| 119 | ENDDO |
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| 120 | |
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| 121 | vsed_aer(:,:)=0.0 |
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| 122 | m_sulf(:,:)=0.0 |
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| 123 | |
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| 124 | DO nb=1,nbtr_bin |
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| 125 | !compute mass-weighted mean of sedimentation velocity |
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| 126 | vsed_aer(:,:)=vsed_aer(:,:)+ZVAER(:,:,nb)*(mdw(nb)/2.)**3*MAX(1.e-30, tr_seri(:,:,nb+nbtr_sulgas)) |
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| 127 | m_sulf(:,:)=m_sulf(:,:)+(mdw(nb)/2.)**3*MAX(1.e-30, tr_seri(:,:,nb+nbtr_sulgas)) |
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| 128 | ENDDO |
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| 129 | |
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| 130 | !divide by total aerosol mass in grid cell |
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| 131 | vsed_aer(:,:)=vsed_aer(:,:)/m_sulf(:,:) |
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| 132 | |
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| 133 | END SUBROUTINE AER_SEDIMNT |
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