| 1 | ! Copyright (c) 2009, Centre National de la Recherche Scientifique |
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| 2 | ! All rights reserved. |
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| 3 | ! $Revision: 88 $, $Date: 2013-11-13 15:08:38 +0100 (mer. 13 nov. 2013) $ |
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| 4 | ! $URL: http://cfmip-obs-sim.googlecode.com/svn/stable/v1.4.0/actsim/lidar_simulator.F90 $ |
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| 5 | |
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| 6 | ! Redistribution and use in source and binary forms, with or without modification, are permitted |
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| 7 | ! provided that the following conditions are met: |
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| 8 | |
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| 9 | ! * Redistributions of source code must retain the above copyright notice, this list |
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| 10 | ! of conditions and the following disclaimer. |
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| 11 | ! * Redistributions in binary form must reproduce the above copyright notice, this list |
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| 12 | ! of conditions and the following disclaimer in the documentation and/or other materials |
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| 13 | ! provided with the distribution. |
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| 14 | ! * Neither the name of the LMD/IPSL/CNRS/UPMC nor the names of its |
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| 15 | ! contributors may be used to endorse or promote products derived from this software without |
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| 16 | ! specific prior written permission. |
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| 17 | |
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| 18 | ! THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR |
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| 19 | ! IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND |
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| 20 | ! FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
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| 21 | ! CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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| 22 | ! DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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| 23 | ! DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER |
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| 24 | ! IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
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| 25 | ! OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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| 26 | |
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| 27 | SUBROUTINE lidar_simulator(npoints,nlev,npart,nrefl & |
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| 28 | , undef & |
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| 29 | , pres, presf, temp & |
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| 30 | , q_lsliq, q_lsice, q_cvliq, q_cvice & |
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| 31 | , ls_radliq, ls_radice, cv_radliq, cv_radice & |
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| 32 | , ice_type, pmol, pnorm, pnorm_perp_tot,tautot, refl ) |
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| 33 | |
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| 34 | !--------------------------------------------------------------------------------- |
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| 35 | ! Purpose: To compute lidar signal from model-simulated profiles of cloud water |
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| 36 | ! and cloud fraction in each sub-column of each model gridbox. |
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| 37 | |
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| 38 | ! References: |
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| 39 | ! Chepfer H., S. Bony, D. Winker, M. Chiriaco, J.-L. Dufresne, G. Seze (2008), |
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| 40 | ! Use of CALIPSO lidar observations to evaluate the cloudiness simulated by a |
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| 41 | ! climate model, Geophys. Res. Lett., 35, L15704, doi:10.1029/2008GL034207. |
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| 42 | |
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| 43 | ! Previous references: |
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| 44 | ! Chiriaco et al, MWR, 2006; Chepfer et al., MWR, 2007 |
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| 45 | |
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| 46 | ! Contacts: Helene Chepfer (chepfer@lmd.polytechnique.fr), Sandrine Bony (bony@lmd.jussieu.fr) |
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| 47 | |
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| 48 | ! May 2007: ActSim code of M. Chiriaco and H. Chepfer rewritten by S. Bony |
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| 49 | |
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| 50 | ! May 2008, H. Chepfer: |
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| 51 | ! - Units of pressure inputs: Pa |
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| 52 | ! - Non Spherical particles : LS Ice NS coefficients, CONV Ice NS coefficients |
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| 53 | ! - New input: ice_type (0=ice-spheres ; 1=ice-non-spherical) |
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| 54 | |
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| 55 | ! June 2008, A. Bodas-Salcedo: |
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| 56 | ! - Ported to Fortran 90 and optimisation changes |
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| 57 | |
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| 58 | ! August 2008, J-L Dufresne: |
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| 59 | ! - Optimisation changes (sum instructions suppressed) |
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| 60 | |
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| 61 | ! October 2008, S. Bony, H. Chepfer and J-L. Dufresne : |
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| 62 | ! - Interface with COSP v2.0: |
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| 63 | ! cloud fraction removed from inputs |
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| 64 | ! in-cloud condensed water now in input (instead of grid-averaged value) |
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| 65 | ! depolarisation diagnostic removed |
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| 66 | ! parasol (polder) reflectances (for 5 different solar zenith angles) added |
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| 67 | |
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| 68 | ! December 2008, S. Bony, H. Chepfer and J-L. Dufresne : |
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| 69 | ! - Modification of the integration of the lidar equation. |
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| 70 | ! - change the cloud detection threshold |
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| 71 | |
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| 72 | ! April 2008, A. Bodas-Salcedo: |
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| 73 | ! - Bug fix in computation of pmol and pnorm of upper layer |
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| 74 | |
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| 75 | ! April 2008, J-L. Dufresne |
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| 76 | ! - Bug fix in computation of pmol and pnorm, thanks to Masaki Satoh: a factor 2 |
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| 77 | ! was missing. This affects the ATB values but not the cloud fraction. |
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| 78 | |
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| 79 | ! January 2013, G. Cesana and H. Chepfer: |
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| 80 | ! - Add the perpendicular component of the backscattered signal (pnorm_perp_tot) in the arguments |
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| 81 | ! - Add the temperature for each levels (temp) in the arguments |
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| 82 | ! - Add the computation of the perpendicular component of the backscattered lidar signal |
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| 83 | ! Reference: Cesana G. and H. Chepfer (2013): Evaluation of the cloud water phase |
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| 84 | ! in a climate model using CALIPSO-GOCCP, J. Geophys. Res., doi: 10.1002/jgrd.50376 |
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| 85 | |
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| 86 | !--------------------------------------------------------------------------------- |
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| 87 | |
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| 88 | ! Inputs: |
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| 89 | ! npoints : number of horizontal points |
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| 90 | ! nlev : number of vertical levels |
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| 91 | ! npart: numberb of cloud meteors (stratiform_liq, stratiform_ice, conv_liq, conv_ice). |
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| 92 | ! Currently npart must be 4 |
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| 93 | ! nrefl: number of solar zenith angles for parasol reflectances |
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| 94 | ! pres : pressure in the middle of atmospheric layers (full levels): Pa |
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| 95 | ! presf: pressure in the interface of atmospheric layers (half levels): Pa |
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| 96 | ! presf(..,1) : surface pressure ; presf(..,nlev+1)= TOA pressure |
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| 97 | ! temp : temperature of atmospheric layers: K |
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| 98 | ! q_lsliq: LS sub-column liquid water mixing ratio (kg/kg) |
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| 99 | ! q_lsice: LS sub-column ice water mixing ratio (kg/kg) |
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| 100 | ! q_cvliq: CONV sub-column liquid water mixing ratio (kg/kg) |
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| 101 | ! q_cvice: CONV sub-column ice water mixing ratio (kg/kg) |
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| 102 | ! ls_radliq: effective radius of LS liquid particles (meters) |
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| 103 | ! ls_radice: effective radius of LS ice particles (meters) |
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| 104 | ! cv_radliq: effective radius of CONV liquid particles (meters) |
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| 105 | ! cv_radice: effective radius of CONV ice particles (meters) |
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| 106 | ! ice_type : ice particle shape hypothesis (ice_type=0 for spheres, ice_type=1 |
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| 107 | ! for non spherical particles) |
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| 108 | |
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| 109 | ! Outputs: |
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| 110 | ! pmol : molecular attenuated backscatter lidar signal power (m^-1.sr^-1) |
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| 111 | ! pnorm: total attenuated backscatter lidar signal power (m^-1.sr^-1) |
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| 112 | ! pnorm_perp_tot: perpendicular attenuated backscatter lidar signal power (m^-1.sr^-1) |
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| 113 | ! tautot: optical thickess integrated from top to level z |
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| 114 | ! refl : parasol(polder) reflectance |
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| 115 | |
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| 116 | ! Version 1.0 (June 2007) |
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| 117 | ! Version 1.1 (May 2008) |
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| 118 | ! Version 1.2 (June 2008) |
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| 119 | ! Version 2.0 (October 2008) |
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| 120 | ! Version 2.1 (December 2008) |
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| 121 | !--------------------------------------------------------------------------------- |
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| 122 | |
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| 123 | USE MOD_COSP_CONSTANTS, only : ok_debug_cosp |
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| 124 | IMPLICIT NONE |
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| 125 | REAL :: SRsat |
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| 126 | PARAMETER (SRsat = 0.01) ! threshold full attenuation |
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| 127 | |
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| 128 | LOGICAL ok_parasol |
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| 129 | PARAMETER (ok_parasol=.true.) ! set to .true. if you want to activate parasol reflectances |
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| 130 | |
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| 131 | INTEGER i, k |
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| 132 | |
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| 133 | INTEGER INDX_LSLIQ,INDX_LSICE,INDX_CVLIQ,INDX_CVICE |
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| 134 | PARAMETER (INDX_LSLIQ=1,INDX_LSICE=2,INDX_CVLIQ=3,INDX_CVICE=4) |
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| 135 | ! inputs: |
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| 136 | INTEGER npoints,nlev,npart,ice_type |
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| 137 | INTEGER nrefl |
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| 138 | real undef ! undefined value |
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| 139 | REAL pres(npoints,nlev) ! pressure full levels |
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| 140 | REAL presf(npoints,nlev+1) ! pressure half levels |
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| 141 | REAL q_lsliq(npoints,nlev), q_lsice(npoints,nlev) |
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| 142 | REAL q_cvliq(npoints,nlev), q_cvice(npoints,nlev) |
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| 143 | REAL ls_radliq(npoints,nlev), ls_radice(npoints,nlev) |
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| 144 | REAL cv_radliq(npoints,nlev), cv_radice(npoints,nlev) |
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| 145 | |
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| 146 | ! outputs (for each subcolumn): |
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| 147 | |
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| 148 | REAL pmol(npoints,nlev) ! molecular backscatter signal power (m^-1.sr^-1) |
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| 149 | REAL pnorm(npoints,nlev) ! total lidar backscatter signal power (m^-1.sr^-1) |
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| 150 | REAL tautot(npoints,nlev)! optical thickess integrated from top |
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| 151 | REAL refl(npoints,nrefl)! parasol reflectance ! parasol |
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| 152 | |
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| 153 | ! actsim variables: |
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| 154 | |
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| 155 | REAL km, rdiffm, Qscat, Cmol |
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| 156 | PARAMETER (Cmol = 6.2446e-32) ! depends on wavelength |
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| 157 | PARAMETER (km = 1.38e-23) ! Boltzmann constant (J/K) |
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| 158 | |
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| 159 | PARAMETER (rdiffm = 0.7) ! multiple scattering correction parameter |
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| 160 | PARAMETER (Qscat = 2.0) ! particle scattering efficiency at 532 nm |
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| 161 | |
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| 162 | REAL rholiq, rhoice |
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| 163 | PARAMETER (rholiq=1.0e+03) ! liquid water (kg/m3) |
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| 164 | PARAMETER (rhoice=0.5e+03) ! ice (kg/m3) |
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| 165 | |
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| 166 | REAL pi, rhopart(npart) |
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| 167 | REAL polpart(npart,5) ! polynomial coefficients derived for spherical and non spherical |
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| 168 | ! particules |
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| 169 | |
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| 170 | ! grid-box variables: |
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| 171 | REAL rad_part(npoints,nlev,npart) |
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| 172 | REAL rhoair(npoints,nlev), zheight(npoints,nlev+1) |
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| 173 | REAL beta_mol(npoints,nlev), alpha_mol(npoints,nlev) |
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| 174 | REAL kp_part(npoints,nlev,npart) |
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| 175 | |
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| 176 | ! sub-column variables: |
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| 177 | REAL qpart(npoints,nlev,npart) ! mixing ratio particles in each subcolumn |
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| 178 | REAL alpha_part(npoints,nlev,npart) |
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| 179 | REAL tau_mol_lay(npoints) ! temporary variable, moL. opt. thickness of layer k |
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| 180 | REAL tau_mol(npoints,nlev) ! optical thickness between TOA and bottom of layer k |
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| 181 | REAL tau_part(npoints,nlev,npart) |
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| 182 | REAL betatot(npoints,nlev) |
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| 183 | REAL tautot_lay(npoints) ! temporary variable, total opt. thickness of layer k |
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| 184 | ! Optical thickness from TOA to surface for Parasol |
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| 185 | REAL tautot_S_liq(npoints),tautot_S_ice(npoints) ! for liq and ice clouds |
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| 186 | |
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| 187 | |
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| 188 | ! Local variables |
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| 189 | REAL Alpha, Beta, Gamma ! Polynomial coefficient for ATBperp computation |
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| 190 | REAL temp(npoints,nlev) ! temperature of layer k |
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| 191 | REAL betatot_ice(npoints,nlev) ! backscatter coefficient for ice particles |
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| 192 | REAL beta_perp_ice(npoints,nlev) ! perpendicular backscatter coefficient for ice |
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| 193 | REAL betatot_liq(npoints,nlev) ! backscatter coefficient for liquid particles |
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| 194 | REAL beta_perp_liq(npoints,nlev) ! perpendicular backscatter coefficient for liq |
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| 195 | REAL tautot_ice(npoints,nlev) ! total optical thickness of ice |
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| 196 | REAL tautot_liq(npoints,nlev) ! total optical thickness of liq |
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| 197 | REAL tautot_lay_ice(npoints) ! total optical thickness of ice in the layer k |
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| 198 | REAL tautot_lay_liq(npoints) ! total optical thickness of liq in the layer k |
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| 199 | REAL pnorm_liq(npoints,nlev) ! lidar backscattered signal power for liquid |
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| 200 | REAL pnorm_ice(npoints,nlev) ! lidar backscattered signal power for ice |
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| 201 | REAL pnorm_perp_ice(npoints,nlev) ! perpendicular lidar backscattered signal power for ice |
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| 202 | REAL pnorm_perp_liq(npoints,nlev) ! perpendicular lidar backscattered signal power for liq |
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| 203 | |
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| 204 | REAL :: seuil |
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| 205 | |
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| 206 | ! Output variable |
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| 207 | REAL pnorm_perp_tot (npoints,nlev) ! perpendicular lidar backscattered signal power |
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| 208 | |
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| 209 | !------------------------------------------------------------ |
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| 210 | !---- 0. Initialisation : |
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| 211 | !------------------------------------------------------------ |
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| 212 | betatot_ice(:,:)=0 |
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| 213 | betatot_liq(:,:)=0 |
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| 214 | beta_perp_ice(:,:)=0 |
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| 215 | beta_perp_liq(:,:)=0 |
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| 216 | tautot_ice(:,:)=0 |
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| 217 | tautot_liq(:,:)=0 |
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| 218 | tautot_lay_ice(:)=0; |
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| 219 | tautot_lay_liq(:)=0; |
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| 220 | pnorm_liq(:,:)=0 |
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| 221 | pnorm_ice(:,:)=0 |
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| 222 | pnorm_perp_ice(:,:)=0 |
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| 223 | pnorm_perp_liq(:,:)=0 |
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| 224 | pnorm_perp_tot(:,:)=0 |
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| 225 | |
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| 226 | |
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| 227 | ! Polynomial coefficients (Alpha, Beta, Gamma) which allow to compute the ATBperpendicular |
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| 228 | ! as a function of the ATB for ice or liquid cloud particles derived from CALIPSO-GOCCP |
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| 229 | ! observations at 120m vertical grid (Cesana and Chepfer, JGR, 2013). |
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| 230 | |
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| 231 | ! Relationship between ATBice and ATBperp,ice for ice particles |
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| 232 | ! ATBperp,ice = Alpha*ATBice |
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| 233 | Alpha = 0.2904 |
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| 234 | |
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| 235 | ! Relationship between ATBice and ATBperp,ice for liquid particles |
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| 236 | ! ATBperp,ice = Beta*ATBice^2 + Gamma*ATBice |
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| 237 | Beta = 0.4099 |
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| 238 | Gamma = 0.009 |
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| 239 | |
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| 240 | if (ok_debug_cosp) then |
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| 241 | seuil=1.e-18 |
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| 242 | else |
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| 243 | seuil=0.0 |
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| 244 | endif |
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| 245 | !------------------------------------------------------------ |
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| 246 | !---- 1. Preliminary definitions and calculations : |
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| 247 | !------------------------------------------------------------ |
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| 248 | |
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| 249 | if ( npart .ne. 4 ) then |
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| 250 | PRINT *,'Error in lidar_simulator, npart should be 4, not',npart |
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| 251 | stop |
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| 252 | endif |
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| 253 | |
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| 254 | pi = dacos(-1.D0) |
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| 255 | |
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| 256 | ! Polynomial coefficients for spherical liq/ice particles derived from Mie theory. |
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| 257 | ! Polynomial coefficients for non spherical particles derived from a composite of |
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| 258 | ! Ray-tracing theory for large particles (e.g. Noel et al., Appl. Opt., 2001) |
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| 259 | ! and FDTD theory for very small particles (Yang et al., JQSRT, 2003). |
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| 260 | |
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| 261 | ! We repeat the same coefficients for LS and CONV cloud to make code more readable |
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| 262 | !* LS Liquid water coefficients: |
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| 263 | polpart(INDX_LSLIQ,1) = 2.6980e-8 |
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| 264 | polpart(INDX_LSLIQ,2) = -3.7701e-6 |
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| 265 | polpart(INDX_LSLIQ,3) = 1.6594e-4 |
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| 266 | polpart(INDX_LSLIQ,4) = -0.0024 |
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| 267 | polpart(INDX_LSLIQ,5) = 0.0626 |
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| 268 | !* LS Ice coefficients: |
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| 269 | if (ice_type.eq.0) then |
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| 270 | polpart(INDX_LSICE,1) = -1.0176e-8 |
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| 271 | polpart(INDX_LSICE,2) = 1.7615e-6 |
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| 272 | polpart(INDX_LSICE,3) = -1.0480e-4 |
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| 273 | polpart(INDX_LSICE,4) = 0.0019 |
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| 274 | polpart(INDX_LSICE,5) = 0.0460 |
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| 275 | endif |
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| 276 | !* LS Ice NS coefficients: |
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| 277 | if (ice_type.eq.1) then |
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| 278 | polpart(INDX_LSICE,1) = 1.3615e-8 |
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| 279 | polpart(INDX_LSICE,2) = -2.04206e-6 |
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| 280 | polpart(INDX_LSICE,3) = 7.51799e-5 |
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| 281 | polpart(INDX_LSICE,4) = 0.00078213 |
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| 282 | polpart(INDX_LSICE,5) = 0.0182131 |
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| 283 | endif |
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| 284 | !* CONV Liquid water coefficients: |
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| 285 | polpart(INDX_CVLIQ,1) = 2.6980e-8 |
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| 286 | polpart(INDX_CVLIQ,2) = -3.7701e-6 |
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| 287 | polpart(INDX_CVLIQ,3) = 1.6594e-4 |
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| 288 | polpart(INDX_CVLIQ,4) = -0.0024 |
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| 289 | polpart(INDX_CVLIQ,5) = 0.0626 |
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| 290 | !* CONV Ice coefficients: |
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| 291 | if (ice_type.eq.0) then |
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| 292 | polpart(INDX_CVICE,1) = -1.0176e-8 |
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| 293 | polpart(INDX_CVICE,2) = 1.7615e-6 |
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| 294 | polpart(INDX_CVICE,3) = -1.0480e-4 |
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| 295 | polpart(INDX_CVICE,4) = 0.0019 |
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| 296 | polpart(INDX_CVICE,5) = 0.0460 |
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| 297 | endif |
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| 298 | if (ice_type.eq.1) then |
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| 299 | polpart(INDX_CVICE,1) = 1.3615e-8 |
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| 300 | polpart(INDX_CVICE,2) = -2.04206e-6 |
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| 301 | polpart(INDX_CVICE,3) = 7.51799e-5 |
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| 302 | polpart(INDX_CVICE,4) = 0.00078213 |
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| 303 | polpart(INDX_CVICE,5) = 0.0182131 |
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| 304 | endif |
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| 305 | |
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| 306 | ! density: |
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| 307 | !* clear-sky air: |
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| 308 | rhoair = pres/(287.04*temp) |
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| 309 | |
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| 310 | !* liquid/ice particules: |
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| 311 | rhopart(INDX_LSLIQ) = rholiq |
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| 312 | rhopart(INDX_LSICE) = rhoice |
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| 313 | rhopart(INDX_CVLIQ) = rholiq |
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| 314 | rhopart(INDX_CVICE) = rhoice |
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| 315 | |
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| 316 | ! effective radius particles: |
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| 317 | rad_part(:,:,INDX_LSLIQ) = ls_radliq(:,:) |
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| 318 | rad_part(:,:,INDX_LSICE) = ls_radice(:,:) |
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| 319 | rad_part(:,:,INDX_CVLIQ) = cv_radliq(:,:) |
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| 320 | rad_part(:,:,INDX_CVICE) = cv_radice(:,:) |
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| 321 | rad_part(:,:,:)=MAX(rad_part(:,:,:),0.) |
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| 322 | rad_part(:,:,:)=MIN(rad_part(:,:,:),70.0e-6) |
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| 323 | |
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| 324 | ! altitude at half pressure levels: |
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| 325 | zheight(:,1) = 0.0 |
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| 326 | DO k = 2, nlev+1 |
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| 327 | zheight(:,k) = zheight(:,k-1) & |
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| 328 | -(presf(:,k)-presf(:,k-1))/(rhoair(:,k-1)*9.81) |
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| 329 | enddo |
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| 330 | |
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| 331 | !------------------------------------------------------------ |
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| 332 | !---- 2. Molecular alpha and beta: |
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| 333 | !------------------------------------------------------------ |
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| 334 | |
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| 335 | beta_mol = pres/km/temp * Cmol |
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| 336 | alpha_mol = 8.0*pi/3.0 * beta_mol |
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| 337 | |
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| 338 | !------------------------------------------------------------ |
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| 339 | !---- 3. Particles alpha and beta: |
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| 340 | !------------------------------------------------------------ |
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| 341 | |
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| 342 | ! polynomes kp_lidar derived from Mie theory: |
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| 343 | DO i = 1, npart |
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| 344 | where ( rad_part(:,:,i).gt.0.0) |
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| 345 | kp_part(:,:,i) = & |
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| 346 | polpart(i,1)*(rad_part(:,:,i)*1e6)**4 & |
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| 347 | + polpart(i,2)*(rad_part(:,:,i)*1e6)**3 & |
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| 348 | + polpart(i,3)*(rad_part(:,:,i)*1e6)**2 & |
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| 349 | + polpart(i,4)*(rad_part(:,:,i)*1e6) & |
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| 350 | + polpart(i,5) |
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| 351 | elsewhere |
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| 352 | kp_part(:,:,i) = 0. |
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| 353 | endwhere |
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| 354 | enddo |
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| 355 | |
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| 356 | ! mixing ratio particules in each subcolumn: |
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| 357 | qpart(:,:,INDX_LSLIQ) = q_lsliq(:,:) ! oct08 |
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| 358 | qpart(:,:,INDX_LSICE) = q_lsice(:,:) ! oct08 |
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| 359 | qpart(:,:,INDX_CVLIQ) = q_cvliq(:,:) ! oct08 |
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| 360 | qpart(:,:,INDX_CVICE) = q_cvice(:,:) ! oct08 |
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| 361 | |
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| 362 | ! alpha of particles in each subcolumn: |
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| 363 | DO i = 1, npart |
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| 364 | where ( rad_part(:,:,i).gt.0.0) |
|---|
| 365 | alpha_part(:,:,i) = 3.0/4.0 * Qscat & |
|---|
| 366 | * rhoair(:,:) * qpart(:,:,i) & |
|---|
| 367 | / (rhopart(i) * rad_part(:,:,i) ) |
|---|
| 368 | elsewhere |
|---|
| 369 | alpha_part(:,:,i) = 0. |
|---|
| 370 | endwhere |
|---|
| 371 | enddo |
|---|
| 372 | |
|---|
| 373 | !------------------------------------------------------------ |
|---|
| 374 | !---- 4.1 Total Backscatter signal: |
|---|
| 375 | !------------------------------------------------------------ |
|---|
| 376 | |
|---|
| 377 | ! optical thickness (molecular): |
|---|
| 378 | ! opt. thick of each layer |
|---|
| 379 | tau_mol(:,1:nlev) = alpha_mol(:,1:nlev) & |
|---|
| 380 | & *(zheight(:,2:nlev+1)-zheight(:,1:nlev)) |
|---|
| 381 | ! opt. thick from TOA |
|---|
| 382 | DO k = nlev-1, 1, -1 |
|---|
| 383 | tau_mol(:,k) = tau_mol(:,k) + tau_mol(:,k+1) |
|---|
| 384 | ENDDO |
|---|
| 385 | |
|---|
| 386 | ! optical thickness (particles): |
|---|
| 387 | |
|---|
| 388 | tau_part = rdiffm * alpha_part |
|---|
| 389 | DO i = 1, npart |
|---|
| 390 | ! opt. thick of each layer |
|---|
| 391 | tau_part(:,:,i) = tau_part(:,:,i) & |
|---|
| 392 | & * (zheight(:,2:nlev+1)-zheight(:,1:nlev) ) |
|---|
| 393 | ! opt. thick from TOA |
|---|
| 394 | DO k = nlev-1, 1, -1 |
|---|
| 395 | tau_part(:,k,i) = tau_part(:,k,i) + tau_part(:,k+1,i) |
|---|
| 396 | ENDDO |
|---|
| 397 | ENDDO |
|---|
| 398 | |
|---|
| 399 | ! molecular signal: |
|---|
| 400 | ! Upper layer |
|---|
| 401 | pmol(:,nlev) = beta_mol(:,nlev) / (2.*tau_mol(:,nlev)) & |
|---|
| 402 | & * (1.-exp(-2.0*tau_mol(:,nlev))) |
|---|
| 403 | ! Other layers |
|---|
| 404 | DO k= nlev-1, 1, -1 |
|---|
| 405 | tau_mol_lay(:) = tau_mol(:,k)-tau_mol(:,k+1) ! opt. thick. of layer k |
|---|
| 406 | WHERE (tau_mol_lay(:).GT.0.) |
|---|
| 407 | pmol(:,k) = beta_mol(:,k) * EXP(-2.0*tau_mol(:,k+1)) / (2.*tau_mol_lay(:)) & |
|---|
| 408 | & * (1.-exp(-2.0*tau_mol_lay(:))) |
|---|
| 409 | ELSEWHERE |
|---|
| 410 | ! This must never happend, but just in case, to avoid div. by 0 |
|---|
| 411 | pmol(:,k) = beta_mol(:,k) * EXP(-2.0*tau_mol(:,k+1)) |
|---|
| 412 | END WHERE |
|---|
| 413 | END DO |
|---|
| 414 | |
|---|
| 415 | ! Total signal (molecular + particules): |
|---|
| 416 | |
|---|
| 417 | |
|---|
| 418 | ! For performance reason on vector computers, the 2 following lines should not be used |
|---|
| 419 | ! and should be replace by the later one. |
|---|
| 420 | ! betatot(:,:) = beta_mol(:,:) + sum(kp_part*alpha_part,dim=3) |
|---|
| 421 | ! tautot(:,:) = tau_mol(:,:) + sum(tau_part,dim=3) |
|---|
| 422 | betatot(:,:) = beta_mol(:,:) |
|---|
| 423 | tautot(:,:) = tau_mol(:,:) |
|---|
| 424 | DO i = 1, npart |
|---|
| 425 | betatot(:,:) = betatot(:,:) + kp_part(:,:,i)*alpha_part(:,:,i) |
|---|
| 426 | tautot(:,:) = tautot(:,:) + tau_part(:,:,i) |
|---|
| 427 | ENDDO ! i |
|---|
| 428 | |
|---|
| 429 | ! Upper layer |
|---|
| 430 | pnorm(:,nlev) = betatot(:,nlev) / (2.*tautot(:,nlev)) & |
|---|
| 431 | & * (1.-exp(-2.0*tautot(:,nlev))) |
|---|
| 432 | |
|---|
| 433 | ! Other layers |
|---|
| 434 | DO k= nlev-1, 1, -1 |
|---|
| 435 | tautot_lay(:) = tautot(:,k)-tautot(:,k+1) ! optical thickness of layer k |
|---|
| 436 | WHERE (tautot_lay(:).GT.0.) |
|---|
| 437 | pnorm(:,k) = betatot(:,k) * EXP(-2.0*tautot(:,k+1)) / (2.*tautot_lay(:)) & |
|---|
| 438 | & * (1.-EXP(-2.0*tautot_lay(:))) |
|---|
| 439 | ELSEWHERE |
|---|
| 440 | ! This must never happend, but just in case, to avoid div. by 0 |
|---|
| 441 | pnorm(:,k) = betatot(:,k) * EXP(-2.0*tautot(:,k+1)) |
|---|
| 442 | END WHERE |
|---|
| 443 | END DO |
|---|
| 444 | |
|---|
| 445 | !------------------------------------------------------------ |
|---|
| 446 | !---- 4.2 Ice/Liq Backscatter signal: |
|---|
| 447 | !------------------------------------------------------------ |
|---|
| 448 | |
|---|
| 449 | ! Contribution of the molecular to beta |
|---|
| 450 | betatot_ice(:,:) = beta_mol(:,:) |
|---|
| 451 | betatot_liq(:,:) = beta_mol(:,:) |
|---|
| 452 | |
|---|
| 453 | tautot_ice(:,:) = tau_mol(:,:) |
|---|
| 454 | tautot_liq(:,:) = tau_mol(:,:) |
|---|
| 455 | |
|---|
| 456 | DO i = 2, npart,2 |
|---|
| 457 | betatot_ice(:,:) = betatot_ice(:,:)+ kp_part(:,:,i)*alpha_part(:,:,i) |
|---|
| 458 | tautot_ice(:,:) = tautot_ice(:,:) + tau_part(:,:,i) |
|---|
| 459 | ENDDO ! i |
|---|
| 460 | DO i = 1, npart,2 |
|---|
| 461 | betatot_liq(:,:) = betatot_liq(:,:)+ kp_part(:,:,i)*alpha_part(:,:,i) |
|---|
| 462 | tautot_liq(:,:) = tautot_liq(:,:) + tau_part(:,:,i) |
|---|
| 463 | ENDDO ! i |
|---|
| 464 | |
|---|
| 465 | |
|---|
| 466 | ! Computation of the ice and liquid lidar backscattered signal (ATBice and ATBliq) |
|---|
| 467 | ! Ice only |
|---|
| 468 | ! Upper layer |
|---|
| 469 | pnorm_ice(:,nlev) = betatot_ice(:,nlev) / (2.*tautot_ice(:,nlev)) & |
|---|
| 470 | & * (1.-exp(-2.0*tautot_ice(:,nlev))) |
|---|
| 471 | |
|---|
| 472 | DO k= nlev-1, 1, -1 |
|---|
| 473 | tautot_lay_ice(:) = tautot_ice(:,k)-tautot_ice(:,k+1) |
|---|
| 474 | WHERE (tautot_lay_ice(:).GT.0.) |
|---|
| 475 | pnorm_ice(:,k)=betatot_ice(:,k)*EXP(-2.0*tautot_ice(:,k+1))/(2.*tautot_lay_ice(:)) & |
|---|
| 476 | & * (1.-EXP(-2.0*tautot_lay_ice(:))) |
|---|
| 477 | ELSEWHERE |
|---|
| 478 | pnorm_ice(:,k)=betatot_ice(:,k)*EXP(-2.0*tautot_ice(:,k+1)) |
|---|
| 479 | END WHERE |
|---|
| 480 | ENDDO |
|---|
| 481 | |
|---|
| 482 | ! Liquid only |
|---|
| 483 | ! Upper layer |
|---|
| 484 | pnorm_liq(:,nlev) = betatot_liq(:,nlev) / (2.*tautot_liq(:,nlev)) & |
|---|
| 485 | & * (1.-exp(-2.0*tautot_liq(:,nlev))) |
|---|
| 486 | |
|---|
| 487 | DO k= nlev-1, 1, -1 |
|---|
| 488 | tautot_lay_liq(:) = tautot_liq(:,k)-tautot_liq(:,k+1) |
|---|
| 489 | WHERE (tautot_lay_liq(:).GT.0.) |
|---|
| 490 | pnorm_liq(:,k)=betatot_liq(:,k)*EXP(-2.0*tautot_liq(:,k+1))/(2.*tautot_lay_liq(:)) & |
|---|
| 491 | & * (1.-EXP(-2.0*tautot_lay_liq(:))) |
|---|
| 492 | ELSEWHERE |
|---|
| 493 | pnorm_liq(:,k)=betatot_liq(:,k)*EXP(-2.0*tautot_liq(:,k+1)) |
|---|
| 494 | END WHERE |
|---|
| 495 | ENDDO |
|---|
| 496 | |
|---|
| 497 | |
|---|
| 498 | ! Computation of ATBperp,ice/liq from ATBice/liq including the multiple scattering |
|---|
| 499 | ! contribution (Cesana and Chepfer 2013, JGR) |
|---|
| 500 | ! ATBperp,ice = Alpha*ATBice |
|---|
| 501 | ! ATBperp,liq = Beta*ATBliq^2 + Gamma*ATBliq |
|---|
| 502 | |
|---|
| 503 | DO k= nlev, 1, -1 |
|---|
| 504 | pnorm_perp_ice(:,k) = Alpha * pnorm_ice(:,k) ! Ice particles |
|---|
| 505 | pnorm_perp_liq(:,k) = 1000*Beta * pnorm_liq(:,k)**2 + Gamma * pnorm_liq(:,k) ! Liquid particles |
|---|
| 506 | ENDDO |
|---|
| 507 | |
|---|
| 508 | ! Computation of beta_perp_ice/liq using the lidar equation |
|---|
| 509 | ! Ice only |
|---|
| 510 | ! Upper layer |
|---|
| 511 | beta_perp_ice(:,nlev) = pnorm_perp_ice(:,nlev) * (2.*tautot_ice(:,nlev)) & |
|---|
| 512 | & / (1.-exp(-2.0*tautot_ice(:,nlev))) |
|---|
| 513 | |
|---|
| 514 | DO k= nlev-1, 1, -1 |
|---|
| 515 | tautot_lay_ice(:) = tautot_ice(:,k)-tautot_ice(:,k+1) |
|---|
| 516 | WHERE (tautot_lay_ice(:).GT.0.) |
|---|
| 517 | beta_perp_ice(:,k) = pnorm_perp_ice(:,k)/ EXP(-2.0*tautot_ice(:,k+1)) * (2.*tautot_lay_ice(:)) & |
|---|
| 518 | & / (1.-exp(-2.0*tautot_lay_ice(:))) |
|---|
| 519 | |
|---|
| 520 | ELSEWHERE |
|---|
| 521 | beta_perp_ice(:,k)=pnorm_perp_ice(:,k)/EXP(-2.0*tautot_ice(:,k+1)) |
|---|
| 522 | END WHERE |
|---|
| 523 | ENDDO |
|---|
| 524 | |
|---|
| 525 | ! Liquid only |
|---|
| 526 | ! Upper layer |
|---|
| 527 | beta_perp_liq(:,nlev) = pnorm_perp_liq(:,nlev) * (2.*tautot_liq(:,nlev)) & |
|---|
| 528 | & / (1.-exp(-2.0*tautot_liq(:,nlev))) |
|---|
| 529 | |
|---|
| 530 | DO k= nlev-1, 1, -1 |
|---|
| 531 | tautot_lay_liq(:) = tautot_liq(:,k)-tautot_liq(:,k+1) |
|---|
| 532 | WHERE (tautot_lay_liq(:).GT.0.) |
|---|
| 533 | beta_perp_liq(:,k) = pnorm_perp_liq(:,k)/ max(seuil,EXP(-2.0*tautot_liq(:,k+1))) & |
|---|
| 534 | & * (2.*tautot_lay_liq(:)) / (1.-exp(-2.0*tautot_lay_liq(:))) |
|---|
| 535 | |
|---|
| 536 | ELSEWHERE |
|---|
| 537 | beta_perp_liq(:,k)=pnorm_perp_liq(:,k)/EXP(-2.0*tautot_liq(:,k+1)) |
|---|
| 538 | END WHERE |
|---|
| 539 | ENDDO |
|---|
| 540 | |
|---|
| 541 | |
|---|
| 542 | |
|---|
| 543 | !------------------------------------------------------------ |
|---|
| 544 | !---- 4.3 Perpendicular Backscatter signal: |
|---|
| 545 | !------------------------------------------------------------ |
|---|
| 546 | |
|---|
| 547 | ! Computation of the total perpendicular lidar signal (ATBperp for liq+ice) |
|---|
| 548 | ! Upper layer |
|---|
| 549 | WHERE(tautot(:,nlev).GT.0) |
|---|
| 550 | pnorm_perp_tot(:,nlev) = & |
|---|
| 551 | (beta_perp_ice(:,nlev)+beta_perp_liq(:,nlev)-(beta_mol(:,nlev)/(1+1/0.0284))) / (2.*tautot(:,nlev)) & |
|---|
| 552 | & * (1.-exp(-2.0*tautot(:,nlev))) |
|---|
| 553 | ELSEWHERE |
|---|
| 554 | pnorm_perp_tot(:,nlev) = 0. |
|---|
| 555 | ENDWHERE |
|---|
| 556 | |
|---|
| 557 | ! Other layers |
|---|
| 558 | DO k= nlev-1, 1, -1 |
|---|
| 559 | tautot_lay(:) = tautot(:,k)-tautot(:,k+1) ! optical thickness of layer k |
|---|
| 560 | |
|---|
| 561 | ! The perpendicular component of the molecular backscattered signal (Betaperp) has been |
|---|
| 562 | ! taken into account two times (once for liquid and once for ice). |
|---|
| 563 | ! We remove one contribution using |
|---|
| 564 | ! Betaperp=beta_mol(:,k)/(1+1/0.0284)) [bodhaine et al. 1999] in the following equations: |
|---|
| 565 | WHERE (pnorm(:,k).eq.0) |
|---|
| 566 | pnorm_perp_tot(:,k)=0. |
|---|
| 567 | ELSEWHERE |
|---|
| 568 | WHERE (tautot_lay(:).GT.0.) |
|---|
| 569 | pnorm_perp_tot(:,k) = & |
|---|
| 570 | (beta_perp_ice(:,k)+beta_perp_liq(:,k)-(beta_mol(:,k)/(1+1/0.0284))) * & |
|---|
| 571 | EXP(-2.0*tautot(:,k+1)) / (2.*tautot_lay(:)) & |
|---|
| 572 | & * (1.-EXP(-2.0*tautot_lay(:))) |
|---|
| 573 | ELSEWHERE |
|---|
| 574 | ! This must never happen, but just in case, to avoid div. by 0 |
|---|
| 575 | pnorm_perp_tot(:,k) = & |
|---|
| 576 | (beta_perp_ice(:,k)+beta_perp_liq(:,k)-(beta_mol(:,k)/(1+1/0.0284))) * & |
|---|
| 577 | EXP(-2.0*tautot(:,k+1)) |
|---|
| 578 | END WHERE |
|---|
| 579 | ENDWHERE |
|---|
| 580 | |
|---|
| 581 | END DO |
|---|
| 582 | |
|---|
| 583 | !-------- End computation Lidar -------------------------- |
|---|
| 584 | |
|---|
| 585 | !--------------------------------------------------------- |
|---|
| 586 | ! Parasol/Polder module |
|---|
| 587 | |
|---|
| 588 | ! Purpose : Compute reflectance for one particular viewing direction |
|---|
| 589 | ! and 5 solar zenith angles (calculation valid only over ocean) |
|---|
| 590 | ! --------------------------------------------------------- |
|---|
| 591 | |
|---|
| 592 | ! initialization: |
|---|
| 593 | refl(:,:) = 0.0 |
|---|
| 594 | |
|---|
| 595 | ! activate parasol calculations: |
|---|
| 596 | if (ok_parasol) then |
|---|
| 597 | |
|---|
| 598 | ! Optical thickness from TOA to surface |
|---|
| 599 | tautot_S_liq = 0. |
|---|
| 600 | tautot_S_ice = 0. |
|---|
| 601 | tautot_S_liq(:) = tautot_S_liq(:) & |
|---|
| 602 | + tau_part(:,1,1) + tau_part(:,1,3) |
|---|
| 603 | tautot_S_ice(:) = tautot_S_ice(:) & |
|---|
| 604 | + tau_part(:,1,2) + tau_part(:,1,4) |
|---|
| 605 | |
|---|
| 606 | call parasol(npoints,nrefl,undef & |
|---|
| 607 | ,tautot_S_liq,tautot_S_ice & |
|---|
| 608 | ,refl) |
|---|
| 609 | |
|---|
| 610 | endif ! ok_parasol |
|---|
| 611 | |
|---|
| 612 | END SUBROUTINE lidar_simulator |
|---|
| 613 | |
|---|
| 614 | !--------------------------------------------------------------------------------- |
|---|
| 615 | |
|---|
| 616 | SUBROUTINE parasol(npoints,nrefl,undef & |
|---|
| 617 | ,tautot_S_liq,tautot_S_ice & |
|---|
| 618 | ,refl) |
|---|
| 619 | !--------------------------------------------------------------------------------- |
|---|
| 620 | ! Purpose: To compute Parasol reflectance signal from model-simulated profiles |
|---|
| 621 | ! of cloud water and cloud fraction in each sub-column of each model |
|---|
| 622 | ! gridbox. |
|---|
| 623 | |
|---|
| 624 | |
|---|
| 625 | ! December 2008, S. Bony, H. Chepfer and J-L. Dufresne : |
|---|
| 626 | ! - optimization for vectorization |
|---|
| 627 | |
|---|
| 628 | ! Version 2.0 (October 2008) |
|---|
| 629 | ! Version 2.1 (December 2008) |
|---|
| 630 | !--------------------------------------------------------------------------------- |
|---|
| 631 | |
|---|
| 632 | IMPLICIT NONE |
|---|
| 633 | |
|---|
| 634 | ! inputs |
|---|
| 635 | INTEGER npoints ! Number of horizontal gridpoints |
|---|
| 636 | INTEGER nrefl ! Number of angles for which the reflectance |
|---|
| 637 | ! is computed. Can not be greater then ntetas |
|---|
| 638 | REAL undef ! Undefined value. Currently not used |
|---|
| 639 | REAL tautot_S_liq(npoints) ! liquid water cloud optical thickness, |
|---|
| 640 | ! integrated from TOA to surface |
|---|
| 641 | REAL tautot_S_ice(npoints) ! same for ice water clouds only |
|---|
| 642 | ! outputs |
|---|
| 643 | REAL refl(npoints,nrefl) ! Parasol reflectances |
|---|
| 644 | |
|---|
| 645 | ! Local variables |
|---|
| 646 | REAL tautot_S(npoints) ! cloud optical thickness, from TOA to surface |
|---|
| 647 | REAL frac_taucol_liq(npoints), frac_taucol_ice(npoints) |
|---|
| 648 | |
|---|
| 649 | REAL pi |
|---|
| 650 | ! look up table variables: |
|---|
| 651 | INTEGER ny, it |
|---|
| 652 | INTEGER ntetas, nbtau ! number of angle and of optical thickness |
|---|
| 653 | ! of the look-up table |
|---|
| 654 | PARAMETER (ntetas=5, nbtau=7) |
|---|
| 655 | REAL aa(ntetas,nbtau-1), ab(ntetas,nbtau-1) |
|---|
| 656 | REAL ba(ntetas,nbtau-1), bb(ntetas,nbtau-1) |
|---|
| 657 | REAL tetas(ntetas),tau(nbtau) |
|---|
| 658 | REAL r_norm(ntetas) |
|---|
| 659 | REAL rlumA(ntetas,nbtau), rlumB(ntetas,nbtau) |
|---|
| 660 | REAL rlumA_mod(npoints,5), rlumB_mod(npoints,5) |
|---|
| 661 | |
|---|
| 662 | DATA tau /0., 1., 5., 10., 20., 50., 100./ |
|---|
| 663 | DATA tetas /0., 20., 40., 60., 80./ |
|---|
| 664 | |
|---|
| 665 | ! Look-up table for spherical liquid particles: |
|---|
| 666 | DATA (rlumA(1,ny),ny=1,nbtau) /0.03, 0.090886, 0.283965, & |
|---|
| 667 | 0.480587, 0.695235, 0.908229, 1.0 / |
|---|
| 668 | DATA (rlumA(2,ny),ny=1,nbtau) /0.03, 0.072185, 0.252596, & |
|---|
| 669 | 0.436401, 0.631352, 0.823924, 0.909013 / |
|---|
| 670 | DATA (rlumA(3,ny),ny=1,nbtau) /0.03, 0.058410, 0.224707, & |
|---|
| 671 | 0.367451, 0.509180, 0.648152, 0.709554 / |
|---|
| 672 | DATA (rlumA(4,ny),ny=1,nbtau) /0.03, 0.052498, 0.175844, & |
|---|
| 673 | 0.252916, 0.326551, 0.398581, 0.430405 / |
|---|
| 674 | DATA (rlumA(5,ny),ny=1,nbtau) /0.03, 0.034730, 0.064488, & |
|---|
| 675 | 0.081667, 0.098215, 0.114411, 0.121567 / |
|---|
| 676 | |
|---|
| 677 | ! Look-up table for ice particles: |
|---|
| 678 | DATA (rlumB(1,ny),ny=1,nbtau) /0.03, 0.092170, 0.311941, & |
|---|
| 679 | 0.511298, 0.712079 , 0.898243 , 0.976646 / |
|---|
| 680 | DATA (rlumB(2,ny),ny=1,nbtau) /0.03, 0.087082, 0.304293, & |
|---|
| 681 | 0.490879, 0.673565, 0.842026, 0.912966 / |
|---|
| 682 | DATA (rlumB(3,ny),ny=1,nbtau) /0.03, 0.083325, 0.285193, & |
|---|
| 683 | 0.430266, 0.563747, 0.685773, 0.737154 / |
|---|
| 684 | DATA (rlumB(4,ny),ny=1,nbtau) /0.03, 0.084935, 0.233450, & |
|---|
| 685 | 0.312280, 0.382376, 0.446371, 0.473317 / |
|---|
| 686 | DATA (rlumB(5,ny),ny=1,nbtau) /0.03, 0.054157, 0.089911, & |
|---|
| 687 | 0.107854, 0.124127, 0.139004, 0.145269 / |
|---|
| 688 | |
|---|
| 689 | !-------------------------------------------------------------------------------- |
|---|
| 690 | ! Lum_norm=f(tetaS,tau_cloud) derived from adding-doubling calculations |
|---|
| 691 | ! valid ONLY ABOVE OCEAN (albedo_sfce=5%) |
|---|
| 692 | ! valid only in one viewing direction (theta_v=30�, phi_s-phi_v=320�) |
|---|
| 693 | ! based on adding-doubling radiative transfer computation |
|---|
| 694 | ! for tau values (0 to 100) and for tetas values (0 to 80) |
|---|
| 695 | ! for 2 scattering phase functions: liquid spherical, ice non spherical |
|---|
| 696 | |
|---|
| 697 | IF ( nrefl.GT. ntetas ) THEN |
|---|
| 698 | PRINT *,'Error in lidar_simulator, nrefl should be less then ',ntetas,' not',nrefl |
|---|
| 699 | STOP |
|---|
| 700 | ENDIF |
|---|
| 701 | |
|---|
| 702 | rlumA_mod=0 |
|---|
| 703 | rlumB_mod=0 |
|---|
| 704 | |
|---|
| 705 | pi = ACOS(-1.0) |
|---|
| 706 | r_norm(:)=1./ COS(pi/180.*tetas(:)) |
|---|
| 707 | |
|---|
| 708 | tautot_S_liq(:)=MAX(tautot_S_liq(:),tau(1)) |
|---|
| 709 | tautot_S_ice(:)=MAX(tautot_S_ice(:),tau(1)) |
|---|
| 710 | tautot_S(:) = tautot_S_ice(:) + tautot_S_liq(:) |
|---|
| 711 | |
|---|
| 712 | ! relative fraction of the opt. thick due to liquid or ice clouds |
|---|
| 713 | WHERE (tautot_S(:) .GT. 0.) |
|---|
| 714 | frac_taucol_liq(:) = tautot_S_liq(:) / tautot_S(:) |
|---|
| 715 | frac_taucol_ice(:) = tautot_S_ice(:) / tautot_S(:) |
|---|
| 716 | ELSEWHERE |
|---|
| 717 | frac_taucol_liq(:) = 1. |
|---|
| 718 | frac_taucol_ice(:) = 0. |
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| 719 | END WHERE |
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| 720 | tautot_S(:)=MIN(tautot_S(:),tau(nbtau)) |
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| 721 | |
|---|
| 722 | ! Linear interpolation : |
|---|
| 723 | |
|---|
| 724 | DO ny=1,nbtau-1 |
|---|
| 725 | ! microphysics A (liquid clouds) |
|---|
| 726 | aA(:,ny) = (rlumA(:,ny+1)-rlumA(:,ny))/(tau(ny+1)-tau(ny)) |
|---|
| 727 | bA(:,ny) = rlumA(:,ny) - aA(:,ny)*tau(ny) |
|---|
| 728 | ! microphysics B (ice clouds) |
|---|
| 729 | aB(:,ny) = (rlumB(:,ny+1)-rlumB(:,ny))/(tau(ny+1)-tau(ny)) |
|---|
| 730 | bB(:,ny) = rlumB(:,ny) - aB(:,ny)*tau(ny) |
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| 731 | ENDDO |
|---|
| 732 | |
|---|
| 733 | DO it=1,ntetas |
|---|
| 734 | DO ny=1,nbtau-1 |
|---|
| 735 | WHERE (tautot_S(:).GE.tau(ny).AND.tautot_S(:).LE.tau(ny+1)) |
|---|
| 736 | rlumA_mod(:,it) = aA(it,ny)*tautot_S(:) + bA(it,ny) |
|---|
| 737 | rlumB_mod(:,it) = aB(it,ny)*tautot_S(:) + bB(it,ny) |
|---|
| 738 | END WHERE |
|---|
| 739 | END DO |
|---|
| 740 | END DO |
|---|
| 741 | |
|---|
| 742 | DO it=1,ntetas |
|---|
| 743 | refl(:,it) = frac_taucol_liq(:) * rlumA_mod(:,it) & |
|---|
| 744 | + frac_taucol_ice(:) * rlumB_mod(:,it) |
|---|
| 745 | ! normalized radiance -> reflectance: |
|---|
| 746 | refl(:,it) = refl(:,it) * r_norm(it) |
|---|
| 747 | ENDDO |
|---|
| 748 | |
|---|
| 749 | RETURN |
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| 750 | END SUBROUTINE parasol |
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