| 1 | |
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| 2 | ! $Header$ |
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| 3 | |
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| 4 | |
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| 5 | ! ================================================================================ |
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| 6 | |
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| 7 | SUBROUTINE clouds_bigauss(klon, nd, r, rs, qtc, sigt, ptconv, ratqsc, cldf) |
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| 8 | IMPLICIT NONE |
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| 9 | |
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| 10 | ! -------------------------------------------------------------------------------- |
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| 11 | |
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| 12 | ! Inputs: |
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| 13 | |
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| 14 | ! ND----------: Number of vertical levels |
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| 15 | ! R--------ND-: Domain-averaged mixing ratio of total water |
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| 16 | ! RS-------ND-: Mean saturation humidity mixing ratio within the gridbox |
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| 17 | ! QSUB-----ND-: Mixing ratio of condensed water within clouds associated |
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| 18 | ! with SUBGRID-SCALE condensation processes (here, it is |
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| 19 | ! predicted by the convection scheme) |
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| 20 | ! Outputs: |
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| 21 | |
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| 22 | ! PTCONV-----ND-: Point convectif = TRUE |
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| 23 | ! RATQSC-----ND-: Largeur normalisee de la distribution |
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| 24 | ! CLDF-----ND-: Fraction nuageuse |
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| 25 | |
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| 26 | ! -------------------------------------------------------------------------------- |
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| 27 | |
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| 28 | |
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| 29 | INTEGER klon, nd |
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| 30 | REAL r(klon, nd), rs(klon, nd), qtc(klon, nd), sigt(klon, nd) |
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| 31 | LOGICAL ptconv(klon, nd) |
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| 32 | REAL ratqsc(klon, nd) |
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| 33 | REAL cldf(klon, nd) |
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| 34 | |
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| 35 | ! -- parameters controlling the iteration: |
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| 36 | ! -- nmax : maximum nb of iterations (hopefully never reached) |
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| 37 | ! -- epsilon : accuracy of the numerical resolution |
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| 38 | ! -- vmax : v-value above which we use an asymptotic expression for |
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| 39 | ! ERF(v) |
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| 40 | |
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| 41 | INTEGER nmax |
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| 42 | PARAMETER (nmax=10) |
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| 43 | REAL epsilon, vmax0, vmax(klon) |
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| 44 | PARAMETER (epsilon=0.02, vmax0=2.0) |
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| 45 | |
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| 46 | REAL min_mu, min_q |
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| 47 | PARAMETER (min_mu=1.E-12, min_q=1.E-12) |
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| 48 | |
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| 49 | INTEGER i, k, n, m |
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| 50 | REAL mu, qsat, delta |
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| 51 | REAL sigma1, sigma2, alpha, qconv |
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| 52 | REAL xconv, xenv |
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| 53 | REAL cconv, cenv |
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| 54 | REAL pi, u, v |
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| 55 | REAL erf |
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| 56 | REAL sqrtpi, sqrt2 |
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| 57 | ! lconv = true si le calcul a converge (entre autre si qsub < min_q) |
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| 58 | LOGICAL lconv(klon) |
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| 59 | |
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| 60 | |
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| 61 | cldf(1:klon, 1:nd) = 0.0 ! cym |
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| 62 | ratqsc(1:klon, 1:nd) = 0.0 |
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| 63 | ptconv(1:klon, 1:nd) = .FALSE. |
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| 64 | ! cdir end arraycomb |
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| 65 | |
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| 66 | pi = acos(-1.) |
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| 67 | sqrtpi = sqrt(pi) |
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| 68 | sqrt2 = sqrt(2.) |
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| 69 | |
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| 70 | |
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| 71 | DO k = 1, nd |
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| 72 | |
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| 73 | DO i = 1, klon ! vector |
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| 74 | |
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| 75 | mu = r(i, k) |
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| 76 | mu = max(mu, min_mu) |
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| 77 | qsat = rs(i, k) |
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| 78 | qsat = max(qsat, min_mu) |
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| 79 | delta = log(mu/qsat) |
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| 80 | qconv=qtc(i,k) |
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| 81 | alpha=sigt(i,k) |
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| 82 | |
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| 83 | IF (qconv<min_q) THEN |
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| 84 | ptconv(i, k) = .FALSE. |
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| 85 | ratqsc(i, k) = 0. |
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| 86 | |
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| 87 | ! Rien on a deja initialise |
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| 88 | |
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| 89 | ELSE |
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| 90 | |
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| 91 | sigma1=0.1*((qconv-mu)**2)**0.5+0.002*mu |
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| 92 | sigma2=0.1*((qconv-mu)**2)**0.5+0.002*qconv |
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| 93 | |
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| 94 | ! sigma2=0.09*((qconv-mu)**2)**0.5/(alpha+0.01)**0.5+0.002*qconv |
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| 95 | !----------------------------------------------------------------------------------------------------------------- |
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| 96 | ! Calcul de la couverture nuageuse et de ratqs |
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| 97 | !----------------------------------------------------------------------------------------------------------------- |
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| 98 | |
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| 99 | xconv=(qsat-qconv)/(sqrt(2.)*sigma2) |
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| 100 | xenv=(qsat-mu)/(sqrt(2.)*sigma1) |
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| 101 | |
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| 102 | cconv=0.5*(1.-1.*erf(xconv)) |
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| 103 | cenv=0.5*(1.-1.*erf(xenv)) |
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| 104 | cldf(i,k)=alpha*cconv+(1.-1.*alpha)*cenv |
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| 105 | ratqsc(i,k)= alpha*sigma1+(1.-1.*alpha)*sigma2 |
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| 106 | ptconv(i,k)= .TRUE. |
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| 107 | |
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| 108 | END IF |
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| 109 | |
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| 110 | END DO ! vector |
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| 111 | |
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| 112 | |
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| 113 | END DO ! K |
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| 114 | |
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| 115 | RETURN |
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| 116 | END SUBROUTINE clouds_bigauss |
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| 117 | |
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| 118 | |
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| 119 | |
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