[152] | 1 | MODULE albedo |
---|
| 2 | !!====================================================================== |
---|
| 3 | !! *** MODULE albedo *** |
---|
| 4 | !! Ocean forcing: bulk thermohaline forcing of the ocean (or ice) |
---|
| 5 | !!===================================================================== |
---|
[1601] | 6 | !! History : 8.0 ! 2001-04 (LIM 1.0) |
---|
| 7 | !! NEMO 1.0 ! 2003-07 (C. Ethe, G. Madec) Optimization (old name:shine) |
---|
| 8 | !! - ! 2004-11 (C. Talandier) add albedo_init |
---|
| 9 | !! - ! 2001-06 (M. Vancoppenolle) LIM 3.0 |
---|
| 10 | !! - ! 2006-08 (G. Madec) cleaning for surface module |
---|
[152] | 11 | !!---------------------------------------------------------------------- |
---|
[1601] | 12 | |
---|
| 13 | !!---------------------------------------------------------------------- |
---|
[3625] | 14 | !! albedo_ice : albedo for ice (clear and overcast skies) |
---|
| 15 | !! albedo_oce : albedo for ocean (clear and overcast skies) |
---|
| 16 | !! albedo_init : initialisation of albedo computation |
---|
[152] | 17 | !!---------------------------------------------------------------------- |
---|
[3625] | 18 | USE phycst ! physical constants |
---|
| 19 | USE in_out_manager ! I/O manager |
---|
| 20 | USE lib_mpp ! MPP library |
---|
| 21 | USE wrk_nemo ! work arrays |
---|
| 22 | USE lib_fortran ! Fortran utilities (allows no signed zero when 'key_nosignedzero' defined) |
---|
[152] | 23 | |
---|
| 24 | IMPLICIT NONE |
---|
| 25 | PRIVATE |
---|
| 26 | |
---|
[1601] | 27 | PUBLIC albedo_ice ! routine called sbcice_lim.F90 |
---|
| 28 | PUBLIC albedo_oce ! routine called by ??? |
---|
[165] | 29 | |
---|
[888] | 30 | INTEGER :: albd_init = 0 !: control flag for initialization |
---|
| 31 | REAL(wp) :: zzero = 0.e0 ! constant values |
---|
| 32 | REAL(wp) :: zone = 1.e0 ! " " |
---|
[152] | 33 | |
---|
[888] | 34 | REAL(wp) :: c1 = 0.05 ! constants values |
---|
| 35 | REAL(wp) :: c2 = 0.10 ! " " |
---|
| 36 | REAL(wp) :: rmue = 0.40 ! cosine of local solar altitude |
---|
| 37 | |
---|
[4147] | 38 | ! !!* namelist namsbc_alb |
---|
| 39 | REAL(wp) :: rn_cloud ! cloudiness effect on snow or ice albedo (Grenfell & Perovich, 1984) |
---|
[833] | 40 | #if defined key_lim3 |
---|
[4147] | 41 | REAL(wp) :: rn_albice ! albedo of melting ice in the arctic and antarctic (Shine & Hendersson-Sellers) |
---|
[833] | 42 | #else |
---|
[4147] | 43 | REAL(wp) :: rn_albice ! albedo of melting ice in the arctic and antarctic (Shine & Hendersson-Sellers) |
---|
[833] | 44 | #endif |
---|
[4147] | 45 | REAL(wp) :: rn_alphd ! coefficients for linear interpolation used to compute |
---|
| 46 | REAL(wp) :: rn_alphdi ! albedo between two extremes values (Pyane, 1972) |
---|
| 47 | REAL(wp) :: rn_alphc ! |
---|
[152] | 48 | |
---|
| 49 | !!---------------------------------------------------------------------- |
---|
[2528] | 50 | !! NEMO/OPA 3.3 , NEMO Consortium (2010) |
---|
[888] | 51 | !! $Id$ |
---|
[2715] | 52 | !! Software governed by the CeCILL licence (NEMOGCM/NEMO_CeCILL.txt) |
---|
[152] | 53 | !!---------------------------------------------------------------------- |
---|
| 54 | CONTAINS |
---|
| 55 | |
---|
[888] | 56 | SUBROUTINE albedo_ice( pt_ice, ph_ice, ph_snw, pa_ice_cs, pa_ice_os ) |
---|
[152] | 57 | !!---------------------------------------------------------------------- |
---|
[888] | 58 | !! *** ROUTINE albedo_ice *** |
---|
[152] | 59 | !! |
---|
| 60 | !! ** Purpose : Computation of the albedo of the snow/ice system |
---|
[888] | 61 | !! as well as the ocean one |
---|
[152] | 62 | !! |
---|
| 63 | !! ** Method : - Computation of the albedo of snow or ice (choose the |
---|
[888] | 64 | !! rignt one by a large number of tests |
---|
[152] | 65 | !! - Computation of the albedo of the ocean |
---|
| 66 | !! |
---|
[888] | 67 | !! References : Shine and Hendersson-Sellers 1985, JGR, 90(D1), 2243-2250. |
---|
| 68 | !!---------------------------------------------------------------------- |
---|
[1463] | 69 | REAL(wp), INTENT(in ), DIMENSION(:,:,:) :: pt_ice ! ice surface temperature (Kelvin) |
---|
[888] | 70 | REAL(wp), INTENT(in ), DIMENSION(:,:,:) :: ph_ice ! sea-ice thickness |
---|
| 71 | REAL(wp), INTENT(in ), DIMENSION(:,:,:) :: ph_snw ! snow thickness |
---|
| 72 | REAL(wp), INTENT( out), DIMENSION(:,:,:) :: pa_ice_cs ! albedo of ice under clear sky |
---|
| 73 | REAL(wp), INTENT( out), DIMENSION(:,:,:) :: pa_ice_os ! albedo of ice under overcast sky |
---|
[719] | 74 | !! |
---|
[888] | 75 | INTEGER :: ji, jj, jl ! dummy loop indices |
---|
| 76 | INTEGER :: ijpl ! number of ice categories (3rd dim of ice input arrays) |
---|
| 77 | REAL(wp) :: zalbpsnm ! albedo of ice under clear sky when snow is melting |
---|
| 78 | REAL(wp) :: zalbpsnf ! albedo of ice under clear sky when snow is freezing |
---|
| 79 | REAL(wp) :: zalbpsn ! albedo of snow/ice system when ice is coverd by snow |
---|
| 80 | REAL(wp) :: zalbpic ! albedo of snow/ice system when ice is free of snow |
---|
| 81 | REAL(wp) :: zithsn ! = 1 for hsn >= 0 ( ice is cov. by snow ) ; = 0 otherwise (ice is free of snow) |
---|
| 82 | REAL(wp) :: zitmlsn ! = 1 freezinz snow (pt_ice >=rt0_snow) ; = 0 melting snow (pt_ice<rt0_snow) |
---|
| 83 | REAL(wp) :: zihsc1 ! = 1 hsn <= c1 ; = 0 hsn > c1 |
---|
| 84 | REAL(wp) :: zihsc2 ! = 1 hsn >= c2 ; = 0 hsn < c2 |
---|
| 85 | !! |
---|
[2715] | 86 | REAL(wp), POINTER, DIMENSION(:,:,:) :: zalbfz ! = rn_alphdi for freezing ice ; = rn_albice for melting ice |
---|
| 87 | REAL(wp), POINTER, DIMENSION(:,:,:) :: zficeth ! function of ice thickness |
---|
[152] | 88 | !!--------------------------------------------------------------------- |
---|
| 89 | |
---|
[888] | 90 | ijpl = SIZE( pt_ice, 3 ) ! number of ice categories |
---|
[165] | 91 | |
---|
[3294] | 92 | CALL wrk_alloc( jpi,jpj,ijpl, zalbfz, zficeth ) |
---|
[2715] | 93 | |
---|
[888] | 94 | IF( albd_init == 0 ) CALL albedo_init ! initialization |
---|
| 95 | |
---|
| 96 | !--------------------------- |
---|
[152] | 97 | ! Computation of zficeth |
---|
[888] | 98 | !--------------------------- |
---|
| 99 | ! ice free of snow and melts |
---|
[2715] | 100 | WHERE ( ph_snw == 0._wp .AND. pt_ice >= rt0_ice ) ; zalbfz(:,:,:) = rn_albice |
---|
| 101 | ELSE WHERE ; zalbfz(:,:,:) = rn_alphdi |
---|
| 102 | END WHERE |
---|
| 103 | |
---|
| 104 | WHERE ( 1.5 < ph_ice ) ; zficeth = zalbfz |
---|
| 105 | ELSE WHERE( 1.0 < ph_ice .AND. ph_ice <= 1.5 ) ; zficeth = 0.472 + 2.0 * ( zalbfz - 0.472 ) * ( ph_ice - 1.0 ) |
---|
| 106 | ELSE WHERE( 0.05 < ph_ice .AND. ph_ice <= 1.0 ) ; zficeth = 0.2467 + 0.7049 * ph_ice & |
---|
| 107 | & - 0.8608 * ph_ice * ph_ice & |
---|
| 108 | & + 0.3812 * ph_ice * ph_ice * ph_ice |
---|
| 109 | ELSE WHERE ; zficeth = 0.1 + 3.6 * ph_ice |
---|
[152] | 110 | END WHERE |
---|
[888] | 111 | |
---|
[2715] | 112 | !!gm old code |
---|
| 113 | ! DO jl = 1, ijpl |
---|
| 114 | ! DO jj = 1, jpj |
---|
| 115 | ! DO ji = 1, jpi |
---|
| 116 | ! IF( ph_ice(ji,jj,jl) > 1.5 ) THEN |
---|
| 117 | ! zficeth(ji,jj,jl) = zalbfz(ji,jj,jl) |
---|
| 118 | ! ELSEIF( ph_ice(ji,jj,jl) > 1.0 .AND. ph_ice(ji,jj,jl) <= 1.5 ) THEN |
---|
| 119 | ! zficeth(ji,jj,jl) = 0.472 + 2.0 * ( zalbfz(ji,jj,jl) - 0.472 ) * ( ph_ice(ji,jj,jl) - 1.0 ) |
---|
| 120 | ! ELSEIF( ph_ice(ji,jj,jl) > 0.05 .AND. ph_ice(ji,jj,jl) <= 1.0 ) THEN |
---|
| 121 | ! zficeth(ji,jj,jl) = 0.2467 + 0.7049 * ph_ice(ji,jj,jl) & |
---|
| 122 | ! & - 0.8608 * ph_ice(ji,jj,jl) * ph_ice(ji,jj,jl) & |
---|
| 123 | ! & + 0.3812 * ph_ice(ji,jj,jl) * ph_ice(ji,jj,jl) * ph_ice (ji,jj,jl) |
---|
| 124 | ! ELSE |
---|
| 125 | ! zficeth(ji,jj,jl) = 0.1 + 3.6 * ph_ice(ji,jj,jl) |
---|
| 126 | ! ENDIF |
---|
| 127 | ! END DO |
---|
| 128 | ! END DO |
---|
| 129 | ! END DO |
---|
| 130 | !!gm end old code |
---|
[152] | 131 | |
---|
| 132 | !----------------------------------------------- |
---|
| 133 | ! Computation of the snow/ice albedo system |
---|
| 134 | !-------------------------- --------------------- |
---|
| 135 | |
---|
| 136 | ! Albedo of snow-ice for clear sky. |
---|
| 137 | !----------------------------------------------- |
---|
[888] | 138 | DO jl = 1, ijpl |
---|
[833] | 139 | DO jj = 1, jpj |
---|
| 140 | DO ji = 1, jpi |
---|
| 141 | ! Case of ice covered by snow. |
---|
[888] | 142 | ! ! freezing snow |
---|
| 143 | zihsc1 = 1.0 - MAX( zzero , SIGN( zone , - ( ph_snw(ji,jj,jl) - c1 ) ) ) |
---|
[1601] | 144 | zalbpsnf = ( 1.0 - zihsc1 ) * ( zficeth(ji,jj,jl) & |
---|
| 145 | & + ph_snw(ji,jj,jl) * ( rn_alphd - zficeth(ji,jj,jl) ) / c1 ) & |
---|
| 146 | & + zihsc1 * rn_alphd |
---|
[888] | 147 | ! ! melting snow |
---|
| 148 | zihsc2 = MAX( zzero , SIGN( zone , ph_snw(ji,jj,jl) - c2 ) ) |
---|
[1601] | 149 | zalbpsnm = ( 1.0 - zihsc2 ) * ( rn_albice + ph_snw(ji,jj,jl) * ( rn_alphc - rn_albice ) / c2 ) & |
---|
| 150 | & + zihsc2 * rn_alphc |
---|
[888] | 151 | ! |
---|
| 152 | zitmlsn = MAX( zzero , SIGN( zone , pt_ice(ji,jj,jl) - rt0_snow ) ) |
---|
| 153 | zalbpsn = zitmlsn * zalbpsnm + ( 1.0 - zitmlsn ) * zalbpsnf |
---|
[833] | 154 | |
---|
| 155 | ! Case of ice free of snow. |
---|
[888] | 156 | zalbpic = zficeth(ji,jj,jl) |
---|
[833] | 157 | |
---|
| 158 | ! albedo of the system |
---|
[888] | 159 | zithsn = 1.0 - MAX( zzero , SIGN( zone , - ph_snw(ji,jj,jl) ) ) |
---|
| 160 | pa_ice_cs(ji,jj,jl) = zithsn * zalbpsn + ( 1.0 - zithsn ) * zalbpic |
---|
[833] | 161 | END DO |
---|
| 162 | END DO |
---|
| 163 | END DO |
---|
| 164 | |
---|
| 165 | ! Albedo of snow-ice for overcast sky. |
---|
| 166 | !---------------------------------------------- |
---|
[1601] | 167 | pa_ice_os(:,:,:) = pa_ice_cs(:,:,:) + rn_cloud ! Oberhuber correction |
---|
[888] | 168 | ! |
---|
[3294] | 169 | CALL wrk_dealloc( jpi,jpj,ijpl, zalbfz, zficeth ) |
---|
[2715] | 170 | ! |
---|
[888] | 171 | END SUBROUTINE albedo_ice |
---|
[833] | 172 | |
---|
| 173 | |
---|
[888] | 174 | SUBROUTINE albedo_oce( pa_oce_os , pa_oce_cs ) |
---|
[152] | 175 | !!---------------------------------------------------------------------- |
---|
[888] | 176 | !! *** ROUTINE albedo_oce *** |
---|
[152] | 177 | !! |
---|
[888] | 178 | !! ** Purpose : Computation of the albedo of the ocean |
---|
| 179 | !!---------------------------------------------------------------------- |
---|
[2715] | 180 | REAL(wp), DIMENSION(:,:), INTENT(out) :: pa_oce_os ! albedo of ocean under overcast sky |
---|
| 181 | REAL(wp), DIMENSION(:,:), INTENT(out) :: pa_oce_cs ! albedo of ocean under clear sky |
---|
[152] | 182 | !! |
---|
[2715] | 183 | REAL(wp) :: zcoef ! local scalar |
---|
[152] | 184 | !!---------------------------------------------------------------------- |
---|
[888] | 185 | ! |
---|
| 186 | zcoef = 0.05 / ( 1.1 * rmue**1.4 + 0.15 ) ! Parameterization of Briegled and Ramanathan, 1982 |
---|
| 187 | pa_oce_cs(:,:) = zcoef |
---|
| 188 | pa_oce_os(:,:) = 0.06 ! Parameterization of Kondratyev, 1969 and Payne, 1972 |
---|
| 189 | ! |
---|
| 190 | END SUBROUTINE albedo_oce |
---|
[152] | 191 | |
---|
| 192 | |
---|
[165] | 193 | SUBROUTINE albedo_init |
---|
| 194 | !!---------------------------------------------------------------------- |
---|
| 195 | !! *** ROUTINE albedo_init *** |
---|
| 196 | !! |
---|
| 197 | !! ** Purpose : initializations for the albedo parameters |
---|
| 198 | !! |
---|
[1601] | 199 | !! ** Method : Read the namelist namsbc_alb |
---|
[165] | 200 | !!---------------------------------------------------------------------- |
---|
[4147] | 201 | INTEGER :: ios ! Local integer output status for namelist read |
---|
[1601] | 202 | NAMELIST/namsbc_alb/ rn_cloud, rn_albice, rn_alphd, rn_alphdi, rn_alphc |
---|
[719] | 203 | !!---------------------------------------------------------------------- |
---|
[1601] | 204 | ! |
---|
| 205 | albd_init = 1 ! indicate that the initialization has been done |
---|
| 206 | ! |
---|
[4147] | 207 | REWIND( numnam_ref ) ! Namelist namsbc_alb in reference namelist : Albedo parameters |
---|
| 208 | READ ( numnam_ref, namsbc_alb, IOSTAT = ios, ERR = 901) |
---|
| 209 | 901 IF( ios /= 0 ) CALL ctl_nam ( ios , 'namsbc_alb in reference namelist', lwp ) |
---|
| 210 | |
---|
| 211 | REWIND( numnam_cfg ) ! Namelist namsbc_alb in configuration namelist : Albedo parameters |
---|
| 212 | READ ( numnam_cfg, namsbc_alb, IOSTAT = ios, ERR = 902 ) |
---|
| 213 | 902 IF( ios /= 0 ) CALL ctl_nam ( ios , 'namsbc_alb in configuration namelist', lwp ) |
---|
[4792] | 214 | IF(lwm) WRITE ( numond, namsbc_alb ) |
---|
[1601] | 215 | ! |
---|
| 216 | IF(lwp) THEN ! Control print |
---|
[165] | 217 | WRITE(numout,*) |
---|
[1601] | 218 | WRITE(numout,*) 'albedo : set albedo parameters' |
---|
| 219 | WRITE(numout,*) '~~~~~~~' |
---|
| 220 | WRITE(numout,*) ' Namelist namsbc_alb : albedo ' |
---|
| 221 | WRITE(numout,*) ' correction for snow and ice albedo rn_cloud = ', rn_cloud |
---|
| 222 | WRITE(numout,*) ' albedo of melting ice in the arctic and antarctic rn_albice = ', rn_albice |
---|
| 223 | WRITE(numout,*) ' coefficients for linear rn_alphd = ', rn_alphd |
---|
| 224 | WRITE(numout,*) ' interpolation used to compute albedo rn_alphdi = ', rn_alphdi |
---|
| 225 | WRITE(numout,*) ' between two extremes values (Pyane, 1972) rn_alphc = ', rn_alphc |
---|
[165] | 226 | ENDIF |
---|
[888] | 227 | ! |
---|
| 228 | END SUBROUTINE albedo_init |
---|
[719] | 229 | |
---|
[152] | 230 | !!====================================================================== |
---|
| 231 | END MODULE albedo |
---|