[7293] | 1 | MODULE limmp |
---|
| 2 | !!====================================================================== |
---|
| 3 | !! *** MODULE limmp *** |
---|
| 4 | !! Melt ponds |
---|
| 5 | !!====================================================================== |
---|
| 6 | !! history : ! Original code by Daniela Flocco and Adrian Turner |
---|
| 7 | !! 1.0 ! 2012 (O. Lecomte) Adaptation for scientific tests (NEMO3.1) |
---|
[8142] | 8 | !! 2.0 ! 2017 (M. Vancoppenolle, O. Lecomte, C. Rousset) Implementation in NEMO3.6 |
---|
[7293] | 9 | !!---------------------------------------------------------------------- |
---|
| 10 | #if defined key_lim3 |
---|
| 11 | !!---------------------------------------------------------------------- |
---|
| 12 | !! 'key_lim3' : LIM3 sea-ice model |
---|
| 13 | !!---------------------------------------------------------------------- |
---|
| 14 | !! lim_mp_init : some initialization and namelist read |
---|
| 15 | !! lim_mp : main calling routine |
---|
| 16 | !!---------------------------------------------------------------------- |
---|
[7325] | 17 | USE phycst ! physical constants |
---|
| 18 | USE dom_oce ! ocean space and time domain |
---|
[7293] | 19 | USE ice ! LIM-3 variables |
---|
[8378] | 20 | ! |
---|
[7293] | 21 | USE lbclnk ! lateral boundary conditions - MPP exchanges |
---|
| 22 | USE lib_mpp ! MPP library |
---|
| 23 | USE in_out_manager ! I/O manager |
---|
| 24 | USE lib_fortran ! glob_sum |
---|
| 25 | USE timing ! Timing |
---|
| 26 | |
---|
| 27 | IMPLICIT NONE |
---|
| 28 | PRIVATE |
---|
| 29 | |
---|
[8321] | 30 | PUBLIC lim_mp_init ! routine called by icestp.F90 |
---|
| 31 | PUBLIC lim_mp ! routine called by icestp.F90 |
---|
[7293] | 32 | |
---|
[8597] | 33 | INTEGER :: nice_pnd ! choice of the type of pond scheme |
---|
| 34 | ! ! associated indices: |
---|
| 35 | INTEGER, PARAMETER :: np_pndNO = 0 ! No pond scheme |
---|
| 36 | INTEGER, PARAMETER :: np_pndCST = 1 ! Constant pond scheme |
---|
| 37 | INTEGER, PARAMETER :: np_pndH12 = 2 ! Evolutive pond scheme (Holland et al. 2012) |
---|
| 38 | |
---|
[7293] | 39 | !! * Substitutions |
---|
| 40 | # include "vectopt_loop_substitute.h90" |
---|
| 41 | !!---------------------------------------------------------------------- |
---|
| 42 | !! NEMO/LIM3 4.0 , UCL - NEMO Consortium (2011) |
---|
| 43 | !! $Id: limdyn.F90 6994 2016-10-05 13:07:10Z clem $ |
---|
| 44 | !! Software governed by the CeCILL licence (NEMOGCM/NEMO_CeCILL.txt) |
---|
| 45 | !!---------------------------------------------------------------------- |
---|
| 46 | CONTAINS |
---|
| 47 | |
---|
[7325] | 48 | SUBROUTINE lim_mp( kt ) |
---|
| 49 | !!------------------------------------------------------------------- |
---|
| 50 | !! *** ROUTINE lim_mp *** |
---|
| 51 | !! |
---|
| 52 | !! ** Purpose : change melt pond fraction |
---|
| 53 | !! |
---|
| 54 | !! ** Method : brutal force |
---|
| 55 | !! |
---|
| 56 | !! ** Action : - |
---|
| 57 | !! - |
---|
| 58 | !!------------------------------------------------------------------------------------ |
---|
[8597] | 59 | INTEGER, INTENT(in) :: kt ! number of iteration |
---|
| 60 | INTEGER :: ji, jj, jl ! dummy loop indices |
---|
[7325] | 61 | !!------------------------------------------------------------------- |
---|
[7293] | 62 | |
---|
[7325] | 63 | IF( nn_timing == 1 ) CALL timing_start('lim_mp') |
---|
[7293] | 64 | |
---|
[8597] | 65 | SELECT CASE ( nice_pnd ) |
---|
[7325] | 66 | |
---|
[8597] | 67 | CASE (np_pndCST) |
---|
| 68 | ! !------------------------------! |
---|
| 69 | CALL lim_mp_CST ! Constant melt ponds ! |
---|
| 70 | ! !------------------------------! |
---|
| 71 | CASE (np_pndH12) |
---|
| 72 | ! !------------------------------! |
---|
| 73 | CALL lim_mp_H12 ! Holland et al 2012 melt ponds! |
---|
| 74 | ! !------------------------------! |
---|
[8061] | 75 | END SELECT |
---|
| 76 | |
---|
[8142] | 77 | IF( nn_timing == 1 ) CALL timing_stop('lim_mp') |
---|
[7325] | 78 | |
---|
| 79 | END SUBROUTINE lim_mp |
---|
| 80 | |
---|
[8597] | 81 | SUBROUTINE lim_mp_CST |
---|
[8098] | 82 | !!------------------------------------------------------------------- |
---|
[8597] | 83 | !! *** ROUTINE lim_mp_CST *** |
---|
[8098] | 84 | !! |
---|
| 85 | !! ** Purpose : Compute melt pond evolution |
---|
| 86 | !! |
---|
| 87 | !! ** Method : Melt pond fraction and thickness are prescribed |
---|
| 88 | !! to non-zero values when t_su = 0C |
---|
| 89 | !! |
---|
| 90 | !! ** Tunable parameters : pond fraction (rn_apnd), pond depth (rn_hpnd) |
---|
| 91 | !! |
---|
| 92 | !! ** Note : Coupling with such melt ponds is only radiative |
---|
| 93 | !! Advection, ridging, rafting... are bypassed |
---|
| 94 | !! |
---|
| 95 | !! ** References : Bush, G.W., and Trump, D.J. (2017) |
---|
| 96 | !! |
---|
| 97 | !!------------------------------------------------------------------- |
---|
[8061] | 98 | |
---|
[8098] | 99 | WHERE ( ( a_i > epsi10 ) .AND. ( t_su >= rt0-epsi06 ) ) |
---|
[8597] | 100 | !! WHERE ( ( a_i > 0._wp ) .AND. ( t_su >= rt0 ) ) |
---|
[8106] | 101 | a_ip_frac = rn_apnd |
---|
[8098] | 102 | h_ip = rn_hpnd |
---|
[8106] | 103 | v_ip = a_ip_frac * a_i * h_ip |
---|
| 104 | a_ip = a_ip_frac * a_i |
---|
[8098] | 105 | ELSE WHERE |
---|
| 106 | a_ip = 0._wp |
---|
| 107 | h_ip = 0._wp |
---|
| 108 | v_ip = 0._wp |
---|
| 109 | a_ip_frac = 0._wp |
---|
| 110 | END WHERE |
---|
| 111 | |
---|
| 112 | wfx_pnd(:,:) = 0._wp |
---|
| 113 | |
---|
[8597] | 114 | END SUBROUTINE lim_mp_CST |
---|
[8098] | 115 | |
---|
[8597] | 116 | SUBROUTINE lim_mp_H12 |
---|
[8060] | 117 | !!------------------------------------------------------------------- |
---|
[8597] | 118 | !! *** ROUTINE lim_mp_H12 *** |
---|
[8060] | 119 | !! |
---|
| 120 | !! ** Purpose : Compute melt pond evolution |
---|
| 121 | !! |
---|
[8061] | 122 | !! ** Method : Empirical method. A fraction of meltwater is accumulated |
---|
| 123 | !! in pond volume. It is then released exponentially when |
---|
[8098] | 124 | !! surface is freezing. |
---|
[8060] | 125 | !! |
---|
[8142] | 126 | !! ** Tunable parameters : (no real expertise yet, ideas?) |
---|
[8060] | 127 | !! |
---|
| 128 | !! ** Note : Stolen from CICE for quick test of the melt pond |
---|
[8061] | 129 | !! radiation and freshwater interfaces |
---|
[8098] | 130 | !! Coupling can be radiative AND freshwater |
---|
| 131 | !! Advection, ridging, rafting are called |
---|
[8060] | 132 | !! |
---|
| 133 | !! ** References : Holland, M. M. et al (J Clim 2012) |
---|
| 134 | !! |
---|
| 135 | !!------------------------------------------------------------------- |
---|
| 136 | |
---|
[8597] | 137 | INTEGER, DIMENSION(jpij) :: indxi ! compressed indices for cells with ice melting |
---|
| 138 | INTEGER, DIMENSION(jpij) :: indxj ! |
---|
[8060] | 139 | |
---|
[8597] | 140 | REAL(wp), DIMENSION(jpi,jpj) :: zwfx_mlw ! available meltwater for melt ponding |
---|
| 141 | REAL(wp), DIMENSION(jpi,jpj,jpl) :: zrfrac ! fraction of available meltwater retained for melt ponding |
---|
[8060] | 142 | |
---|
[8597] | 143 | REAL(wp), PARAMETER :: zrmin = 0.15_wp ! minimum fraction of available meltwater retained for melt ponding |
---|
| 144 | REAL(wp), PARAMETER :: zrmax = 0.70_wp ! maximum '' '' '' '' '' |
---|
| 145 | REAL(wp), PARAMETER :: zrexp = 0.01_wp ! rate constant to refreeze melt ponds |
---|
| 146 | REAL(wp), PARAMETER :: zpnd_aspect = 0.8_wp ! pond aspect ratio |
---|
[8060] | 147 | |
---|
[8597] | 148 | REAL(wp) :: zhi ! dummy ice thickness |
---|
| 149 | REAL(wp) :: zhs ! dummy snow depth |
---|
| 150 | REAL(wp) :: zTp ! reference temperature |
---|
| 151 | REAL(wp) :: zdTs ! dummy temperature difference |
---|
| 152 | REAL(wp) :: z1_rhofw ! inverse freshwater density |
---|
| 153 | REAL(wp) :: z1_zpnd_aspect ! inverse pond aspect ratio |
---|
| 154 | REAL(wp) :: zvpold ! dummy pond volume |
---|
[8060] | 155 | |
---|
[8597] | 156 | INTEGER :: ji, jj, jl, ij ! loop indices |
---|
| 157 | INTEGER :: icells ! size of dummy array |
---|
[8060] | 158 | !!------------------------------------------------------------------- |
---|
[8142] | 159 | z1_rhofw = 1. / rhofw |
---|
| 160 | z1_zpnd_aspect = 1. / zpnd_aspect |
---|
| 161 | zTp = -2. |
---|
[8060] | 162 | |
---|
[8142] | 163 | a_ip_frac(:,:,:) = 0._wp |
---|
| 164 | h_ip (:,:,:) = 0._wp |
---|
| 165 | |
---|
| 166 | !------------------------------------------------------------------ |
---|
| 167 | ! Available melt water for melt ponding and corresponding fraction |
---|
| 168 | !------------------------------------------------------------------ |
---|
| 169 | |
---|
[8179] | 170 | zwfx_mlw(:,:) = MAX( wfx_sum(:,:) + wfx_snw_sum(:,:), 0._wp ) ! available meltwater for melt ponding |
---|
[8060] | 171 | |
---|
[8142] | 172 | ! NB: zwfx_mlw can be slightly negative for very small values (why?) |
---|
| 173 | ! This can in some occasions give negative |
---|
| 174 | ! v_ip in the first category, which then gives crazy pond |
---|
| 175 | ! fractions and crashes the code as soon as the melt-pond |
---|
| 176 | ! radiative coupling is activated |
---|
| 177 | ! if we understand and remove why wfx_sum or wfx_snw could be |
---|
| 178 | ! negative, then, we can remove the MAX |
---|
[8179] | 179 | ! NB: I now changed to wfx_snw_sum, this may fix the problem. |
---|
| 180 | ! We should check |
---|
[8142] | 181 | |
---|
| 182 | zrfrac(:,:,:) = zrmin + ( zrmax - zrmin ) * a_i(:,:,:) |
---|
| 183 | |
---|
| 184 | DO jl = 1, jpl |
---|
[8060] | 185 | |
---|
[8142] | 186 | !------------------------------------------------------------------------------ |
---|
| 187 | ! Identify grid cells where ponds should be updated (can probably be improved) |
---|
| 188 | !------------------------------------------------------------------------------ |
---|
| 189 | indxi(:) = 0 |
---|
| 190 | indxj(:) = 0 |
---|
| 191 | icells = 0 |
---|
| 192 | DO jj = 1, jpj |
---|
| 193 | DO ji = 1, jpi |
---|
| 194 | IF ( a_i(ji,jj,jl) > epsi10 ) THEN |
---|
| 195 | icells = icells + 1 |
---|
| 196 | indxi(icells) = ji |
---|
| 197 | indxj(icells) = jj |
---|
| 198 | ENDIF |
---|
[8597] | 199 | END DO |
---|
| 200 | END DO |
---|
[8142] | 201 | |
---|
| 202 | DO ij = 1, icells |
---|
| 203 | |
---|
| 204 | ji = indxi(ij) |
---|
| 205 | jj = indxj(ij) |
---|
| 206 | |
---|
| 207 | zhi = v_i(ji,jj,jl) / a_i(ji,jj,jl) |
---|
| 208 | zhs = v_s(ji,jj,jl) / a_i(ji,jj,jl) |
---|
| 209 | |
---|
| 210 | IF ( zhi < rn_himin) THEN !--- Remove ponds on thin ice if ice is too thin |
---|
| 211 | |
---|
| 212 | a_ip(ji,jj,jl) = 0._wp !--- Dump ponds |
---|
| 213 | v_ip(ji,jj,jl) = 0._wp |
---|
| 214 | a_ip_frac(ji,jj,jl) = 0._wp |
---|
| 215 | h_ip(ji,jj,jl) = 0._wp |
---|
| 216 | |
---|
[8597] | 217 | IF ( ln_pnd_fwb ) & !--- Give freshwater to the ocean |
---|
[8142] | 218 | wfx_pnd(ji,jj) = wfx_pnd(ji,jj) + v_ip(ji,jj,jl) |
---|
| 219 | |
---|
| 220 | |
---|
| 221 | ELSE !--- Update pond characteristics |
---|
| 222 | |
---|
| 223 | !--- Add retained melt water to melt ponds |
---|
| 224 | ! v_ip should never be positive, otherwise code crashes |
---|
| 225 | ! MV: as far as I saw, UM5 can create very small negative v_ip values |
---|
| 226 | ! hence I added the max, which was not required with Prather (1 yr run) |
---|
| 227 | v_ip(ji,jj,jl) = MAX( v_ip(ji,jj,jl), 0._wp ) + zrfrac(ji,jj,jl) * z1_rhofw * zwfx_mlw(ji,jj) * a_i(ji,jj,jl) * rdt_ice |
---|
| 228 | |
---|
| 229 | !--- Shrink pond due to refreezing |
---|
| 230 | zdTs = MAX ( zTp - t_su(ji,jj,jl) + rt0 , 0. ) |
---|
| 231 | |
---|
| 232 | zvpold = v_ip(ji,jj,jl) |
---|
| 233 | |
---|
| 234 | v_ip(ji,jj,jl) = v_ip(ji,jj,jl) * EXP( zrexp * zdTs / zTp ) |
---|
| 235 | |
---|
| 236 | !--- Dump meltwater due to refreezing ( of course this is wrong |
---|
| 237 | !--- but this parameterization is too simple ) |
---|
[8597] | 238 | IF ( ln_pnd_fwb ) & |
---|
[8142] | 239 | wfx_pnd(ji,jj) = wfx_pnd(ji,jj) + rhofw * ( v_ip(ji,jj,jl) - zvpold ) * r1_rdtice |
---|
| 240 | |
---|
| 241 | a_ip_frac(ji,jj,jl) = MIN( 1._wp , SQRT( v_ip(ji,jj,jl) * z1_zpnd_aspect / a_i(ji,jj,jl) ) ) |
---|
[8179] | 242 | !NB: the SQRT has been a recurring source of crash when v_ip or a_i tuns to be even only slightly negative |
---|
[8142] | 243 | |
---|
| 244 | h_ip(ji,jj,jl) = zpnd_aspect * a_ip_frac(ji,jj,jl) |
---|
| 245 | |
---|
| 246 | a_ip(ji,jj,jl) = a_ip_frac(ji,jj,jl) * a_i(ji,jj,jl) |
---|
| 247 | |
---|
| 248 | ENDIF |
---|
| 249 | |
---|
| 250 | END DO |
---|
| 251 | |
---|
| 252 | END DO ! jpl |
---|
| 253 | |
---|
| 254 | !--- Remove retained meltwater from surface fluxes |
---|
| 255 | |
---|
[8597] | 256 | IF ( ln_pnd_fwb ) THEN |
---|
[8142] | 257 | |
---|
[8597] | 258 | wfx_snw_sum(:,:) = wfx_snw_sum(:,:) * ( 1. - zrmin - ( zrmax - zrmin ) * SUM( a_i(:,:,:), dim=3 ) ) |
---|
| 259 | wfx_sum(:,:) = wfx_sum(:,:) * ( 1. - zrmin - ( zrmax - zrmin ) * SUM( a_i(:,:,:), dim=3 ) ) |
---|
[8179] | 260 | |
---|
[8142] | 261 | ENDIF |
---|
[8060] | 262 | |
---|
[8597] | 263 | END SUBROUTINE lim_mp_H12 |
---|
[8060] | 264 | |
---|
[8597] | 265 | SUBROUTINE lim_mp_init |
---|
| 266 | !!------------------------------------------------------------------- |
---|
| 267 | !! *** ROUTINE lim_mp_init *** |
---|
| 268 | !! |
---|
| 269 | !! ** Purpose : Physical constants and parameters linked to melt ponds |
---|
| 270 | !! over sea ice |
---|
| 271 | !! |
---|
| 272 | !! ** Method : Read the nammp namelist and check the melt pond |
---|
| 273 | !! parameter values called at the first timestep (nit000) |
---|
| 274 | !! |
---|
| 275 | !! ** input : Namelist nammp |
---|
| 276 | !!------------------------------------------------------------------- |
---|
| 277 | INTEGER :: ios, ioptio ! Local integer output status for namelist read |
---|
| 278 | NAMELIST/nammp/ ln_pnd_H12, ln_pnd_fwb, ln_pnd_CST, rn_apnd, rn_hpnd, ln_pnd_alb |
---|
| 279 | !!------------------------------------------------------------------- |
---|
[7325] | 280 | |
---|
[8597] | 281 | REWIND( numnam_ice_ref ) ! Namelist nammp in reference namelist : Melt Ponds |
---|
| 282 | READ ( numnam_ice_ref, nammp, IOSTAT = ios, ERR = 901) |
---|
| 283 | 901 IF( ios /= 0 ) CALL ctl_nam ( ios , 'nammp in reference namelist', lwp ) |
---|
[7325] | 284 | |
---|
[8597] | 285 | REWIND( numnam_ice_cfg ) ! Namelist nammp in configuration namelist : Melt Ponds |
---|
| 286 | READ ( numnam_ice_cfg, nammp, IOSTAT = ios, ERR = 902 ) |
---|
| 287 | 902 IF( ios /= 0 ) CALL ctl_nam ( ios , 'nammp in configuration namelist', lwp ) |
---|
| 288 | IF(lwm) WRITE ( numoni, nammp ) |
---|
| 289 | |
---|
| 290 | IF(lwp) THEN ! control print |
---|
| 291 | WRITE(numout,*) |
---|
| 292 | WRITE(numout,*) 'ice_thd_pnd_init: ice parameters for melt ponds' |
---|
| 293 | WRITE(numout,*) '~~~~~~~~~~~~~~~~' |
---|
| 294 | WRITE(numout,*) ' Namelist namicethd_pnd:' |
---|
| 295 | WRITE(numout,*) ' Evolutive melt pond fraction and depth (Holland et al 2012) ln_pnd_H12 = ', ln_pnd_H12 |
---|
| 296 | WRITE(numout,*) ' Melt ponds store fresh water or not ln_pnd_fwb = ', ln_pnd_fwb |
---|
| 297 | WRITE(numout,*) ' Prescribed melt pond fraction and depth ln_pnd_Cst = ', ln_pnd_CST |
---|
| 298 | WRITE(numout,*) ' Prescribed pond fraction rn_apnd = ', rn_apnd |
---|
| 299 | WRITE(numout,*) ' Prescribed pond depth rn_hpnd = ', rn_hpnd |
---|
| 300 | WRITE(numout,*) ' Melt ponds affect albedo or not ln_pnd_alb = ', ln_pnd_alb |
---|
| 301 | ENDIF |
---|
| 302 | ! |
---|
| 303 | ! !== set the choice of ice pond scheme ==! |
---|
| 304 | ioptio = 0 |
---|
| 305 | nice_pnd = np_pndNO |
---|
| 306 | IF( ln_pnd_CST ) THEN ; ioptio = ioptio + 1 ; nice_pnd = np_pndCST ; ENDIF |
---|
| 307 | IF( ln_pnd_H12 ) THEN ; ioptio = ioptio + 1 ; nice_pnd = np_pndH12 ; ENDIF |
---|
| 308 | IF( ioptio > 1 ) CALL ctl_stop( 'ice_thd_pnd_init: choose one and only one pond scheme (ln_pnd_H12 or ln_pnd_CST)' ) |
---|
[7325] | 309 | |
---|
[8597] | 310 | SELECT CASE( nice_pnd ) |
---|
| 311 | CASE( np_pndNO ) |
---|
| 312 | IF(ln_pnd_fwb) THEN ; ln_pnd_fwb = .FALSE. ; CALL ctl_warn( 'ln_pnd_fwb=false when no ponds' ) ; ENDIF |
---|
| 313 | IF(ln_pnd_alb) THEN ; ln_pnd_alb = .FALSE. ; CALL ctl_warn( 'ln_pnd_alb=false when no ponds' ) ; ENDIF |
---|
| 314 | CASE( np_pndCST) |
---|
| 315 | IF(ln_pnd_fwb) THEN ; ln_pnd_fwb = .FALSE. ; CALL ctl_warn( 'ln_pnd_fwb=false when ln_pnd_CST=true' ) ; ENDIF |
---|
| 316 | END SELECT |
---|
| 317 | ! |
---|
| 318 | END SUBROUTINE lim_mp_init |
---|
| 319 | |
---|
[7325] | 320 | #else |
---|
| 321 | !!---------------------------------------------------------------------- |
---|
[8597] | 322 | !! Default option Empty module NO ESIM sea-ice model |
---|
[7325] | 323 | !!---------------------------------------------------------------------- |
---|
| 324 | #endif |
---|
| 325 | |
---|
| 326 | !!====================================================================== |
---|
| 327 | END MODULE limmp |
---|