| 1 | ! $Header$ |
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| 2 | |
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| 3 | SUBROUTINE clift(p, t, rr, rs, plcl, dplcldt, dplcldq) |
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| 4 | USE lmdz_yomcst |
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| 5 | |
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| 6 | IMPLICIT NONE |
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| 7 | ! *************************************************************** |
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| 8 | ! * * |
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| 9 | ! * CLIFT : COMPUTE LIFTING CONDENSATION LEVEL AND ITS * |
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| 10 | ! * DERIVATIVES RELATIVE TO T AND R * |
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| 11 | ! * (WITHIN 0.2% OF FORMULA OF BOLTON, MON. WEA. REV.,1980) * |
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| 12 | ! * * |
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| 13 | ! * written by : GRANDPEIX Jean-Yves, 17/11/98, 12.39.01 * |
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| 14 | ! * modified by : * |
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| 15 | ! *************************************************************** |
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| 16 | ! * |
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| 17 | ! *Arguments : |
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| 18 | ! * |
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| 19 | ! * Input : P = pressure of level from wich lifting is performed |
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| 20 | ! * T = temperature of level P |
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| 21 | ! * RR = vapour mixing ratio at level P |
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| 22 | ! * RS = vapour saturation mixing ratio at level P |
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| 23 | ! * |
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| 24 | ! * Output : PLCL = lifting condensation level |
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| 25 | ! * DPLCLDT = derivative of PLCL relative to T |
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| 26 | ! * DPLCLDQ = derivative of PLCL relative to R |
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| 27 | ! * |
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| 28 | ! cccccccccccccccccccccc |
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| 29 | ! constantes coherentes avec le modele du Centre Europeen |
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| 30 | ! RD = 1000.0 * 1.380658E-23 * 6.0221367E+23 / 28.9644 |
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| 31 | ! RV = 1000.0 * 1.380658E-23 * 6.0221367E+23 / 18.0153 |
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| 32 | ! CPD = 3.5 * RD |
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| 33 | ! CPV = 4.0 * RV |
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| 34 | ! CL = 4218.0 |
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| 35 | ! CI=2090.0 |
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| 36 | ! CPVMCL=CL-CPV |
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| 37 | ! CLMCI=CL-CI |
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| 38 | ! EPS=RD/RV |
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| 39 | ! ALV0=2.5008E+06 |
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| 40 | ! ALF0=3.34E+05 |
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| 41 | |
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| 42 | ! on utilise les constantes thermo du Centre Europeen: (sb) |
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| 43 | |
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| 44 | REAL :: p, t, rr, rs, plcl, dplcldt, dplcldq, cpd, cpv, cl, cpvmcl, eps, alv0, a, b |
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| 45 | REAL :: rh, chi, alv |
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| 46 | |
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| 47 | cpd = rcpd |
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| 48 | cpv = rcpv |
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| 49 | cl = rcw |
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| 50 | cpvmcl = cl - cpv |
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| 51 | eps = rd / rv |
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| 52 | alv0 = rlvtt |
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| 53 | |
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| 54 | |
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| 55 | ! Bolton formula coefficients : |
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| 56 | a = 1669.0 |
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| 57 | b = 122.0 |
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| 58 | |
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| 59 | rh = rr / rs |
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| 60 | chi = t / (a - b * rh - t) |
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| 61 | plcl = p * (rh**chi) |
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| 62 | |
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| 63 | alv = alv0 - cpvmcl * (t - 273.15) |
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| 64 | |
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| 65 | ! -- sb: correction: |
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| 66 | ! DPLCLDQ = PLCL*CHI*( 1./RR - B*CHI/T/RS*ALOG(RH) ) |
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| 67 | dplcldq = plcl * chi * (1. / rr + b * chi / t / rs * alog(rh)) |
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| 68 | ! sb -- |
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| 69 | |
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| 70 | dplcldt = plcl * chi * ((a - b * rh * (1. + alv / rv / t)) / t**2 * chi * alog(rh) - alv / rv / t**2) |
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| 71 | |
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| 72 | END SUBROUTINE clift |
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