| 1 | SUBROUTINE swrayleigh(kdlon,knu,ppsol,prmu,prayl) |
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| 2 | USE comcstfi_h |
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| 3 | IMPLICIT NONE |
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| 4 | c======================================================================= |
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| 5 | c subject: |
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| 6 | c -------- |
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| 7 | c Computing total rayleigh scat atmospheric optical depth |
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| 8 | c |
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| 9 | c author: F.Forget |
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| 10 | c ------ |
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| 11 | c |
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| 12 | c input: |
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| 13 | c ----- |
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| 14 | c kdlon Number of gridpoint of horizontal grid |
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| 15 | c knu : Solar band # (1 or 2) |
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| 16 | c ppsol surface pressure (Pa) |
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| 17 | c prmu cos of solar zenith angle (=1 when sun at zenith) |
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| 18 | c (CORRECTED for high zenith angle (atmosphere), unlike mu0) |
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| 19 | c |
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| 20 | c output: |
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| 21 | c ------- |
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| 22 | c prayl column optical depth in each model column |
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| 23 | c |
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| 24 | c======================================================================= |
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| 25 | |
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| 26 | c----------------------------------------------------------------------- |
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| 27 | c |
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| 28 | c Declarations : |
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| 29 | c -------------- |
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| 30 | c |
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| 31 | c Input/Output |
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| 32 | c ------------ |
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| 33 | INTEGER kdlon, knu |
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| 34 | |
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| 35 | real ppsol(kdlon),prmu(kdlon),prayl(kdlon) |
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| 36 | c |
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| 37 | c Local variables : |
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| 38 | c ----------------- |
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| 39 | integer JL, K |
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| 40 | c |
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| 41 | c local saved variables |
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| 42 | c --------------------- |
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| 43 | c rayleigh scattering coefficients (from Morcrete et al.EARTH model !) |
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| 44 | real cray(2,6) |
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| 45 | |
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| 46 | DATA (CRAY(1,K),K=1,6) / |
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| 47 | S .428937E-01, .890743E+00,-.288555E+01, |
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| 48 | S .522744E+01,-.469173E+01, .161645E+01/ |
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| 49 | |
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| 50 | DATA (CRAY(2,K),K=1,6) / |
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| 51 | S .697200E-02, .173297E-01,-.850903E-01, |
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| 52 | S .248261E+00,-.302031E+00, .129662E+00/ |
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| 53 | save cray |
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| 54 | c---------------------------------------------------------------------- |
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| 55 | |
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| 56 | DO JL = 1 , KDLON |
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| 57 | |
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| 58 | c Total Rayleigh Optical thickness on Earth at 101325 Pa level |
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| 59 | c ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 60 | c WARNING : the CRAY coefficients are only valid for |
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| 61 | c Spectral interval used in Earth model !!! |
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| 62 | c (i.e. 0.25-0.68 micron and 0.68-4.00 micron |
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| 63 | c ---> should be modified for Mars model !!! |
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| 64 | |
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| 65 | PRAYL(JL) = CRAY(KNU,1) + PRMU(JL) * (CRAY(KNU,2) + PRMU(JL) |
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| 66 | S * (CRAY(KNU,3) + PRMU(JL) * (CRAY(KNU,4) + PRMU(JL) |
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| 67 | S * (CRAY(KNU,5) + PRMU(JL) * CRAY(KNU,6) )))) |
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| 68 | |
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| 69 | c Total local Rayleigh Optical thickness on Mars |
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| 70 | c ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
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| 71 | c - PRAYL above is the total Rayleigh Optical thickness |
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| 72 | c at 101325Pa for Earth atmosphere |
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| 73 | c -> Total Rayleigh Optical thickness on Mars |
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| 74 | c = PRAYL*(Psurf/101325)*9.81/g *2.5 |
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| 75 | c (Extinction coeff of CO2 = 2.5 * N2) |
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| 76 | |
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| 77 | c (Comment the following line to get back bugged version before 01/2000) |
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| 78 | c PRAYL(JL) = PRAYL(JL) * PPSOL(JL) * 2.42e-4/g |
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| 79 | |
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| 80 | END DO |
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| 81 | |
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| 82 | |
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| 83 | return |
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| 84 | end |
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| 85 | |
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