Changeset 12382
- Timestamp:
- 2020-02-13T16:36:44+01:00 (5 years ago)
- Location:
- NEMO/branches/UKMO/NEMO_4.0_add_pond_lids_prints/src
- Files:
-
- 5 edited
-
ICE/icealb.F90 (modified) (4 diffs)
-
ICE/icesbc.F90 (modified) (1 diff)
-
ICE/icethd_pnd.F90 (modified) (4 diffs)
-
ICE/iceupdate.F90 (modified) (1 diff)
-
OCE/SBC/sbccpl.F90 (modified) (3 diffs)
Legend:
- Unmodified
- Added
- Removed
-
NEMO/branches/UKMO/NEMO_4.0_add_pond_lids_prints/src/ICE/icealb.F90
r10888 r12382 45 45 CONTAINS 46 46 47 SUBROUTINE ice_alb( pt_su, ph_ice, ph_snw, ld_pnd_alb, pafrac_pnd, ph_pnd, p alb_cs, palb_os )47 SUBROUTINE ice_alb( pt_su, ph_ice, ph_snw, ld_pnd_alb, pafrac_pnd, ph_pnd, plh_pnd, palb_cs, palb_os ) 48 48 !!---------------------------------------------------------------------- 49 49 !! *** ROUTINE ice_alb *** … … 97 97 REAL(wp), INTENT(in ), DIMENSION(:,:,:) :: pafrac_pnd ! melt pond relative fraction (per unit ice area) 98 98 REAL(wp), INTENT(in ), DIMENSION(:,:,:) :: ph_pnd ! melt pond depth 99 REAL(wp), INTENT(in ), DIMENSION(:,:,:) :: plh_pnd ! melt pond lid thickness 99 100 REAL(wp), INTENT( out), DIMENSION(:,:,:) :: palb_cs ! albedo of ice under clear sky 100 101 REAL(wp), INTENT( out), DIMENSION(:,:,:) :: palb_os ! albedo of ice under overcast sky 102 ! 103 REAL(wp), PARAMETER :: pnd_lid_max = 0.015 ! pond lid thickness above which the ponds disappear from the albedo calculation 104 REAL(wp), PARAMETER :: pnd_lid_min = 0.005 ! pond lid thickness below which the full pond area is used in the albedo calculation 105 ! Note: these two variables are mirrored in sbccpl.F90 (maybe put them in one place...) 101 106 ! 102 107 INTEGER :: ji, jj, jl ! dummy loop indices … … 106 111 REAL(wp) :: zalb_ice, zafrac_ice ! bare sea ice albedo & relative ice fraction 107 112 REAL(wp) :: zalb_snw, zafrac_snw ! snow-covered sea ice albedo & relative snow fraction 113 REAL(wp) :: lfrac_pnd ! The fraction of the meltpond exposed (not inder a frozen lid) 108 114 !!--------------------------------------------------------------------- 109 115 ! … … 123 129 zafrac_snw = 0._wp 124 130 IF( ld_pnd_alb ) THEN 125 zafrac_pnd = pafrac_pnd(ji,jj,jl) 131 IF ( plh_pnd(ji,jj,jl) > pnd_lid_max ) THEN 132 lfrac_pnd = 0._wp 133 ELSE 134 IF ( plh_pnd(ji,jj,jl) < pnd_lid_min ) THEN 135 lfrac_pnd = 1._wp 136 ELSE 137 lfrac_pnd = ( plh_pnd(ji,jj,jl) - pnd_lid_min ) / (pnd_lid_max - pnd_lid_min) 138 END IF 139 END IF 140 zafrac_pnd = pafrac_pnd(ji,jj,jl) * lfrac_pnd 126 141 ELSE 127 142 zafrac_pnd = 0._wp -
NEMO/branches/UKMO/NEMO_4.0_add_pond_lids_prints/src/ICE/icesbc.F90
r10888 r12382 128 128 129 129 ! --- cloud-sky and overcast-sky ice albedos --- ! 130 CALL ice_alb( t_su, h_i, h_s, ln_pnd_alb, a_ip_frac, h_ip, zalb_cs, zalb_os )130 CALL ice_alb( t_su, h_i, h_s, ln_pnd_alb, a_ip_frac, h_ip, lh_ip, zalb_cs, zalb_os ) 131 131 132 132 ! albedo depends on cloud fraction because of non-linear spectral effects -
NEMO/branches/UKMO/NEMO_4.0_add_pond_lids_prints/src/ICE/icethd_pnd.F90
r12379 r12382 129 129 REAL(wp), PARAMETER :: zpnd_aspect = 0.174_wp ! pond aspect ratio 130 130 REAL(wp), PARAMETER :: zTp = -2._wp ! reference temperature 131 REAL(wp), PARAMETER :: freezing_t = 273.0_wp ! temperature below which refreezing occurs 131 132 ! 132 133 REAL(wp) :: zfr_mlt ! fraction of available meltwater retained for melt ponding 133 134 REAL(wp) :: zdv_mlt ! available meltwater for melt ponding 135 REAL(wp) :: actual_mlt ! actual melt water used to make melt ponds (per m2). 136 ! Need to multiply this by ice area to work on volumes. 134 137 REAL(wp) :: z1_Tp ! inverse reference temperature 135 138 REAL(wp) :: z1_rhow ! inverse freshwater density 136 139 REAL(wp) :: z1_zpnd_aspect ! inverse pond aspect ratio 137 140 REAL(wp) :: zfac, zdum 141 REAL(wp) :: t_grad ! Temperature deficit for refreezing 142 REAL(wp) :: omega_dt ! Time independent accumulated variables used for freezing 143 REAL(wp) :: lh_ip_end ! Lid thickness at end of timestep (temporary variable) 144 REAL(wp) :: actual_frz ! Amount of melt pond that freezes 138 145 ! 139 146 INTEGER :: ji ! loop indices … … 142 149 z1_zpnd_aspect = 1._wp / zpnd_aspect 143 150 z1_Tp = 1._wp / zTp 151 152 ! Define time-independent field for use in refreezing 153 omega_dt = 2.0_wp * rcnd_i * rdtice / (rLfus * rhow) 144 154 145 155 DO ji = 1, npti … … 163 173 ! 164 174 ! available meltwater for melt ponding [m, >0] and fraction 165 zdv_mlt = -( dh_i_sum(ji)*rhoi + dh_s_mlt(ji)*rhos ) * z1_rhow * a_i_1d(ji)175 zdv_mlt = -( dh_i_sum(ji)*rhoi + dh_s_mlt(ji)*rhos ) * z1_rhow 166 176 zfr_mlt = zrmin + ( zrmax - zrmin ) * a_i_1d(ji) ! from CICE doc 167 177 !zfr_mlt = zrmin + zrmax * a_i_1d(ji) ! from Holland paper 178 actual_mlt = zfr_mlt * zdv_mlt 168 179 ! 169 180 !--- Pond gowth ---! 170 ! v_ip should never be negative, otherwise code crashes 171 v_ip_1d(ji) = MAX( 0._wp, v_ip_1d(ji) + zfr_mlt * zdv_mlt ) 172 ! 173 ! melt pond mass flux (<0) 174 IF( zdv_mlt > 0._wp ) THEN 175 zfac = zfr_mlt * zdv_mlt * rhow * r1_rdtice 176 wfx_pnd_1d(ji) = wfx_pnd_1d(ji) - zfac 177 ! 178 ! adjust ice/snow melting flux to balance melt pond flux (>0) 179 zdum = zfac / ( wfx_snw_sum_1d(ji) + wfx_sum_1d(ji) ) 180 wfx_snw_sum_1d(ji) = wfx_snw_sum_1d(ji) * (1._wp + zdum) 181 wfx_sum_1d(ji) = wfx_sum_1d(ji) * (1._wp + zdum) 182 ENDIF 181 v_ip_1d(ji) = v_ip_1d(ji) + actual_mlt * a_i_1d(ji) 182 ! 183 !--- Lid shrinking ---! 184 lh_ip_1d(ji) = lh_ip_1d(ji) - actual_mlt 185 ! 183 186 ! 184 187 !--- Pond contraction (due to refreezing) ---! 185 v_ip_1d(ji) = v_ip_1d(ji) * EXP( 0.01_wp * MAX( zTp+rt0 - t_su_1d(ji), 0._wp ) * z1_Tp ) 188 IF ( t_su_1d(ji) < freezing_t .AND. v_ip_1d(ji) > 0._wp ) THEN 189 t_grad = freezing_t - t_su_1d(ji) 190 191 ! The following equation is a rearranged form of: 192 ! lid_thickness_end - lid_thickness_start = rcnd_i * t_grad * rdtice / (0.5*(lid_thickness_end + lid_thickness_start) * rLfus * rhow) 193 ! where: lid_thickness_start = lh_ip_1d(ji) 194 ! lid_thickness_end = lh_ip_end 195 ! omega_dt is a bunch of terms in the equation that do not change 196 ! note the use of rhow instead of rhoi as we are working with volumes and it is easier if the water and ice volumes (for the lid and the pond) are the same 197 ! (have the same density). The lid will eventually remelt anyway so it doesn't matter if we make this simplification. 198 199 lh_ip_end = SQRT(omega_dt * t_grad + lh_ip_1d(ji)**2) 200 actual_frz = lh_ip_end - lh_ip_1d(ji) 201 202 ! Pond shrinking 203 v_ip_1d(ji) = v_ip_1d(ji) - actual_frz * a_ip_1d(ji) 204 205 ! Lid growing 206 lh_ip_1d(ji) = lh_ip_1d(ji) + actual_frz 207 ELSE 208 actual_frz = 0._wp 209 END IF 210 211 ! melt pond mass flux diagnostic (melt only) 212 zfac = actual_mlt * a_i_1d(ji * rhow * r1_rdtice 213 wfx_pnd_1d(ji) = wfx_pnd_1d(ji) - zfac 214 ! 215 ! adjust ice/snow melting flux to balance melt pond flux (>0) 216 zdum = zfac / ( wfx_snw_sum_1d(ji) + wfx_sum_1d(ji) ) 217 wfx_snw_sum_1d(ji) = wfx_snw_sum_1d(ji) * (1._wp + zdum) 218 wfx_sum_1d(ji) = wfx_sum_1d(ji) * (1._wp + zdum) 219 ! 220 ! Make sure pond volume or lid thickness has not gone negative 221 IF ( v_ip_1d(ji) < 0._wp ) v_ip_1d(ji) = 0._wp 222 IF ( lh_ip_1d(ji) < 0._wp ) lh_ip_1d(ji) = 0._wp 186 223 ! 187 224 ! Set new pond area and depth assuming linear relation between h_ip and a_ip_frac … … 190 227 a_ip_frac_1d(ji) = a_ip_1d(ji) / a_i_1d(ji) 191 228 h_ip_1d(ji) = zpnd_aspect * a_ip_frac_1d(ji) 229 230 ! If lid thickness is ten times greater than pond thickness then remove pond 231 IF ( lh_ip_1d(ji) > h_ip_1d(ji) * 10._wp ) THEN 232 a_ip_1d(ji) = 0._wp 233 a_ip_frac_1d(ji) = 0._wp 234 h_ip_1d(ji) = 0._wp 235 lh_ip_1d(ji) = 0._wp 236 v_ip_1d(ji) = 0._wp 237 END IF 192 238 ! 193 239 ENDIF -
NEMO/branches/UKMO/NEMO_4.0_add_pond_lids_prints/src/ICE/iceupdate.F90
r12371 r12382 185 185 ! Snow/ice albedo (only if sent to coupler, useless in forced mode) 186 186 !------------------------------------------------------------------ 187 CALL ice_alb( t_su, h_i, h_s, ln_pnd_alb, a_ip_frac, h_ip, zalb_cs, zalb_os ) ! cloud-sky and overcast-sky ice albedos187 CALL ice_alb( t_su, h_i, h_s, ln_pnd_alb, a_ip_frac, h_ip, lh_ip, zalb_cs, zalb_os ) ! cloud-sky and overcast-sky ice albedos 188 188 ! 189 189 alb_ice(:,:,:) = ( 1._wp - cldf_ice ) * zalb_cs(:,:,:) + cldf_ice * zalb_os(:,:,:) -
NEMO/branches/UKMO/NEMO_4.0_add_pond_lids_prints/src/OCE/SBC/sbccpl.F90
r12374 r12382 2122 2122 INTEGER, INTENT(in) :: kt 2123 2123 ! 2124 REAL(wp), PARAMETER :: pnd_lid_max = 0.015 ! pond lid thickness above which the ponds disappear from the albedo calculation 2125 REAL(wp), PARAMETER :: pnd_lid_min = 0.005 ! pond lid thickness below which the full pond area is used in the albedo calculation 2126 ! Note: these two variables are mirrored in icealb.F90 (maybe put them in one place...) 2127 ! 2124 2128 INTEGER :: ji, jj, jl ! dummy loop indices 2125 2129 INTEGER :: isec, info ! local integer … … 2127 2131 REAL(wp), DIMENSION(jpi,jpj) :: zfr_l, ztmp1, ztmp2, zotx1, zoty1, zotz1, zitx1, zity1, zitz1 2128 2132 REAL(wp), DIMENSION(jpi,jpj,jpl) :: ztmp3, ztmp4 2133 REAL(wp), DIMENSION(jpi,jpj,jpl) :: lfrac_pnd ! The fraction of the meltpond exposed (not inder a frozen lid) 2134 2129 2135 !!---------------------------------------------------------------------- 2130 2136 ! … … 2341 2347 SELECT CASE( sn_snd_mpnd%clcat ) 2342 2348 CASE( 'yes' ) 2343 ztmp3(:,:,1:jpl) = a_ip_frac(:,:,1:jpl) 2349 2350 ! Calculate how much meltpond is exposed (not under a frozen lid) 2351 lfrac_pnd(:,:,1:jpl) = 1.0 2352 WHERE( lh_ip(:,:,1:jpl) > pnd_lid_max ) 2353 lfrac_pnd(:,:,1:jpl) = 0.0 2354 END WHERE 2355 WHERE( lh_ip(:,:,1:jpl) > pnd_lid_min .AND. lh_ip(:,:,1:jpl) <= pnd_lid_max ) 2356 lfrac_pnd(:,:,1:jpl) = ( lh_ip(:,:,1:jpl) - pnd_lid_min ) / (pnd_lid_max - pnd_lid_min) 2357 END WHERE 2358 2359 ztmp3(:,:,1:jpl) = a_ip_frac(:,:,1:jpl) * lfrac_pnd(:,:,1:jpl) 2344 2360 ztmp4(:,:,1:jpl) = h_ip(:,:,1:jpl) 2345 2361 CASE( 'no' )
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