| 1 |
C $Header: /u/gcmpack/MITgcm/pkg/thsice/thsice_calc_thickn.F,v 1.6 2006/05/25 18:03:24 jmc Exp $ |
| 2 |
C $Name: $ |
| 3 |
|
| 4 |
#include "THSICE_OPTIONS.h" |
| 5 |
|
| 6 |
CBOP |
| 7 |
C !ROUTINE: THSICE_CALC_THICKN |
| 8 |
C !INTERFACE: |
| 9 |
SUBROUTINE THSICE_CALC_THICKN( |
| 10 |
I bi, bj, siLo, siHi, sjLo, sjHi, |
| 11 |
I iMin,iMax, jMin,jMax, dBugFlag, |
| 12 |
I iceMask, tFrz, tOce, v2oc, |
| 13 |
I snowP, prcAtm, sHeat, flxCnB, |
| 14 |
U icFrac, hIce, hSnow, tSrf, qIc1, qIc2, |
| 15 |
U frwAtm, fzMlOc, flx2oc, |
| 16 |
O frw2oc, fsalt, |
| 17 |
I myTime, myIter, myThid ) |
| 18 |
C !DESCRIPTION: \bv |
| 19 |
C *==========================================================* |
| 20 |
C | S/R THSICE_CALC_THICKN |
| 21 |
C | o Calculate ice & snow thickness changes |
| 22 |
C *==========================================================* |
| 23 |
C \ev |
| 24 |
C ADAPTED FROM: |
| 25 |
C LANL CICE.v2.0.2 |
| 26 |
C----------------------------------------------------------------------- |
| 27 |
C.. thermodynamics (vertical physics) based on M. Winton 3-layer model |
| 28 |
C.. See Bitz, C. M. and W. H. Lipscomb, 1999: "An energy-conserving |
| 29 |
C.. thermodynamic sea ice model for climate study." J. Geophys. |
| 30 |
C.. Res., 104, 15669 - 15677. |
| 31 |
C.. Winton, M., 1999: "A reformulated three-layer sea ice model." |
| 32 |
C.. Submitted to J. Atmos. Ocean. Technol. |
| 33 |
C.. authors Elizabeth C. Hunke and William Lipscomb |
| 34 |
C.. Fluid Dynamics Group, Los Alamos National Laboratory |
| 35 |
C----------------------------------------------------------------------- |
| 36 |
Cc****subroutine thermo_winton(n,fice,fsnow,dqice,dTsfc) |
| 37 |
C.. Compute temperature change using Winton model with 2 ice layers, of |
| 38 |
C.. which only the top layer has a variable heat capacity. |
| 39 |
|
| 40 |
C !USES: |
| 41 |
IMPLICIT NONE |
| 42 |
|
| 43 |
C == Global variables === |
| 44 |
#include "EEPARAMS.h" |
| 45 |
#include "THSICE_SIZE.h" |
| 46 |
#include "THSICE_PARAMS.h" |
| 47 |
#ifdef ALLOW_AUTODIFF_TAMC |
| 48 |
# include "SIZE.h" |
| 49 |
# include "tamc.h" |
| 50 |
# include "tamc_keys.h" |
| 51 |
#endif |
| 52 |
|
| 53 |
C !INPUT/OUTPUT PARAMETERS: |
| 54 |
C == Routine Arguments == |
| 55 |
C siLo,siHi :: size of input/output array: 1rst dim. lower,higher bounds |
| 56 |
C sjLo,sjHi :: size of input/output array: 2nd dim. lower,higher bounds |
| 57 |
C bi,bj :: tile indices |
| 58 |
C iMin,iMax :: computation domain: 1rst index range |
| 59 |
C jMin,jMax :: computation domain: 2nd index range |
| 60 |
C dBugFlag :: allow to print debugging stuff (e.g. on 1 grid point). |
| 61 |
C--- Input: |
| 62 |
C iceMask :: sea-ice fractional mask [0-1] |
| 63 |
C tFrz (Tf) :: sea-water freezing temperature [oC] (function of S) |
| 64 |
C tOce (oceTs) :: surface level oceanic temperature [oC] |
| 65 |
C v2oc (oceV2s) :: square of ocean surface-level velocity [m2/s2] |
| 66 |
C snowP (snowPr) :: snow precipitation [kg/m2/s] |
| 67 |
C prcAtm (=) :: total precip from the atmosphere [kg/m2/s] |
| 68 |
C sHeat(sHeating):: surf heating flux left to melt snow or ice (= Atmos-conduction) |
| 69 |
C flxCnB (=) :: heat flux conducted through the ice to bottom surface |
| 70 |
C--- Modified (input&output): |
| 71 |
C icFrac(iceFrac):: fraction of grid area covered in ice |
| 72 |
C hIce (hi) :: ice height [m] |
| 73 |
C hSnow (hs) :: snow height [m] |
| 74 |
C tSrf (Tsf) :: surface (ice or snow) temperature |
| 75 |
C qIc1 (qicen) :: ice enthalpy (J/kg), 1rst level |
| 76 |
C qIc2 (qicen) :: ice enthalpy (J/kg), 2nd level |
| 77 |
C frwAtm (evpAtm):: evaporation to the atmosphere [kg/m2/s] (>0 if evaporate) |
| 78 |
C fzMlOc (frzmlt):: ocean mixed-layer freezing/melting potential [W/m2] |
| 79 |
C flx2oc (qleft) :: net heat flux to ocean [W/m2] (> 0 downward) |
| 80 |
C--- Output |
| 81 |
C frw2oc (fresh) :: Total fresh water flux to ocean [kg/m2/s] (> 0 downward) |
| 82 |
C fsalt (=) :: salt flux to ocean [g/m2/s] (> 0 downward) |
| 83 |
C--- Input: |
| 84 |
C myTime :: current Time of simulation [s] |
| 85 |
C myIter :: current Iteration number in simulation |
| 86 |
C myThid :: my Thread Id number |
| 87 |
INTEGER siLo, siHi, sjLo, sjHi |
| 88 |
INTEGER bi,bj |
| 89 |
INTEGER iMin, iMax |
| 90 |
INTEGER jMin, jMax |
| 91 |
LOGICAL dBugFlag |
| 92 |
_RL iceMask(siLo:siHi,sjLo:sjHi) |
| 93 |
_RL tFrz (siLo:siHi,sjLo:sjHi) |
| 94 |
_RL tOce (siLo:siHi,sjLo:sjHi) |
| 95 |
_RL v2oc (siLo:siHi,sjLo:sjHi) |
| 96 |
_RL snowP (siLo:siHi,sjLo:sjHi) |
| 97 |
_RL prcAtm (siLo:siHi,sjLo:sjHi) |
| 98 |
_RL sHeat (siLo:siHi,sjLo:sjHi) |
| 99 |
_RL flxCnB (siLo:siHi,sjLo:sjHi) |
| 100 |
_RL icFrac (siLo:siHi,sjLo:sjHi) |
| 101 |
_RL hIce (siLo:siHi,sjLo:sjHi) |
| 102 |
_RL hSnow (siLo:siHi,sjLo:sjHi) |
| 103 |
_RL tSrf (siLo:siHi,sjLo:sjHi) |
| 104 |
_RL qIc1 (siLo:siHi,sjLo:sjHi) |
| 105 |
_RL qIc2 (siLo:siHi,sjLo:sjHi) |
| 106 |
_RL frwAtm (siLo:siHi,sjLo:sjHi) |
| 107 |
_RL fzMlOc (siLo:siHi,sjLo:sjHi) |
| 108 |
_RL flx2oc (siLo:siHi,sjLo:sjHi) |
| 109 |
_RL frw2oc (siLo:siHi,sjLo:sjHi) |
| 110 |
_RL fsalt (siLo:siHi,sjLo:sjHi) |
| 111 |
_RL myTime |
| 112 |
INTEGER myIter |
| 113 |
INTEGER myThid |
| 114 |
CEOP |
| 115 |
|
| 116 |
#ifdef ALLOW_THSICE |
| 117 |
|
| 118 |
C !LOCAL VARIABLES: |
| 119 |
C--- local copy of input/output argument list variables (see description above) |
| 120 |
_RL frzmlt |
| 121 |
_RL Tf |
| 122 |
_RL oceTs, oceV2s, snowPr |
| 123 |
_RL sHeating |
| 124 |
c _RL flxCnB |
| 125 |
c _RL evpAtm |
| 126 |
_RL iceFrac |
| 127 |
_RL hi |
| 128 |
_RL hs |
| 129 |
_RL Tsf |
| 130 |
_RL qicen(nlyr) |
| 131 |
_RL qleft |
| 132 |
_RL fresh |
| 133 |
c _RL fsalt |
| 134 |
C == Local Variables == |
| 135 |
INTEGER i,j,k ! loop indices |
| 136 |
_RL rec_nlyr ! reciprocal of number of ice layers (real value) |
| 137 |
C evap :: evaporation over snow/ice [kg/m2/s] (>0 if evaporate) |
| 138 |
C Fbot :: oceanic heat flux used to melt/form ice [W/m2] |
| 139 |
_RL evap |
| 140 |
_RL Fbot |
| 141 |
_RL etop ! energy for top melting (J m-2) |
| 142 |
_RL ebot ! energy for bottom melting (J m-2) |
| 143 |
_RL etope ! energy (from top) for lateral melting (J m-2) |
| 144 |
_RL ebote ! energy (from bottom) for lateral melting (J m-2) |
| 145 |
_RL extend ! total energy for lateral melting (J m-2) |
| 146 |
_RL hnew(nlyr) ! new ice layer thickness (m) |
| 147 |
_RL hlyr ! individual ice layer thickness (m) |
| 148 |
_RL dhi ! change in ice thickness |
| 149 |
_RL dhs ! change in snow thickness |
| 150 |
_RL rq ! rho * q for a layer |
| 151 |
_RL rqh ! rho * q * h for a layer |
| 152 |
_RL qbot ! enthalpy for new ice at bottom surf (J/kg) |
| 153 |
_RL dt ! timestep |
| 154 |
_RL esurp ! surplus energy from melting (J m-2) |
| 155 |
_RL mwater0 ! fresh water mass gained/lost (kg/m^2) |
| 156 |
_RL msalt0 ! salt gained/lost (kg/m^2) |
| 157 |
_RL freshe ! fresh water gain from extension melting |
| 158 |
_RL salte ! salt gained from extension melting |
| 159 |
|
| 160 |
_RL ustar, cpchr |
| 161 |
_RL chi, chs |
| 162 |
_RL frace, rs, hq |
| 163 |
|
| 164 |
C- define grid-point location where to print debugging values |
| 165 |
#include "THSICE_DEBUG.h" |
| 166 |
|
| 167 |
1010 FORMAT(A,I3,3F8.3) |
| 168 |
1020 FORMAT(A,1P4E11.3) |
| 169 |
|
| 170 |
C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----| |
| 171 |
|
| 172 |
#ifdef ALLOW_AUTODIFF_TAMC |
| 173 |
act1 = bi - myBxLo(myThid) |
| 174 |
max1 = myBxHi(myThid) - myBxLo(myThid) + 1 |
| 175 |
act2 = bj - myByLo(myThid) |
| 176 |
max2 = myByHi(myThid) - myByLo(myThid) + 1 |
| 177 |
act3 = myThid - 1 |
| 178 |
max3 = nTx*nTy |
| 179 |
act4 = ikey_dynamics - 1 |
| 180 |
#endif /* ALLOW_AUTODIFF_TAMC */ |
| 181 |
|
| 182 |
rec_nlyr = nlyr |
| 183 |
rec_nlyr = 1. _d 0 / rec_nlyr |
| 184 |
dt = thSIce_deltaT |
| 185 |
|
| 186 |
DO j = jMin, jMax |
| 187 |
DO i = iMin, iMax |
| 188 |
#ifdef ALLOW_AUTODIFF_TAMC |
| 189 |
ikey_1 = i |
| 190 |
& + sNx*(j-1) |
| 191 |
& + sNx*sNy*act1 |
| 192 |
& + sNx*sNy*max1*act2 |
| 193 |
& + sNx*sNy*max1*max2*act3 |
| 194 |
& + sNx*sNy*max1*max2*max3*act4 |
| 195 |
#endif /* ALLOW_AUTODIFF_TAMC */ |
| 196 |
C-- |
| 197 |
#ifdef ALLOW_AUTODIFF_TAMC |
| 198 |
CADJ STORE frwatm(i,j) = comlev1_thsice_1, key=ikey_1 |
| 199 |
CADJ STORE fzmloc(i,j) = comlev1_thsice_1, key=ikey_1 |
| 200 |
CADJ STORE hice(i,j) = comlev1_thsice_1, key=ikey_1 |
| 201 |
CADJ STORE hsnow(i,j) = comlev1_thsice_1, key=ikey_1 |
| 202 |
CADJ STORE icfrac(i,j) = comlev1_thsice_1, key=ikey_1 |
| 203 |
CADJ STORE qic1(i,j) = comlev1_thsice_1, key=ikey_1 |
| 204 |
CADJ STORE qic2(i,j) = comlev1_thsice_1, key=ikey_1 |
| 205 |
#endif |
| 206 |
|
| 207 |
IF (iceMask(i,j).GT.0. _d 0) THEN |
| 208 |
Tf = tFrz(i,j) |
| 209 |
oceTs = tOce(i,j) |
| 210 |
oceV2s = v2oc(i,j) |
| 211 |
snowPr = snowP(i,j) |
| 212 |
c prcAtm = prcAtm(i,j) |
| 213 |
sHeating= sHeat(i,j) |
| 214 |
c flxCnB = flxCnB(i,j) |
| 215 |
iceFrac = icFrac(i,j) |
| 216 |
hi = hIce(i,j) |
| 217 |
hs = hSnow(i,j) |
| 218 |
Tsf = tSrf(i,j) |
| 219 |
qicen(1)= qIc1(i,j) |
| 220 |
qicen(2)= qIc2(i,j) |
| 221 |
c evpAtm = frwAtm(i,j) |
| 222 |
frzmlt = fzMlOc(i,j) |
| 223 |
qleft = flx2oc(i,j) |
| 224 |
c fresh = frw2oc(i,j) |
| 225 |
c fsalt = fsalt(i,j) |
| 226 |
C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----| |
| 227 |
C initialize energies |
| 228 |
esurp = 0. _d 0 |
| 229 |
|
| 230 |
evap = frwAtm(i,j) |
| 231 |
|
| 232 |
C...................................................................... |
| 233 |
C.. Compute growth and/or melting at the top and bottom surfaces....... |
| 234 |
C...................................................................... |
| 235 |
|
| 236 |
IF (frzmlt.GE. 0. _d 0) THEN |
| 237 |
C !----------------------------------------------------------------- |
| 238 |
C ! freezing conditions |
| 239 |
C !----------------------------------------------------------------- |
| 240 |
C if higher than hihig, use all frzmlt energy to grow extra ice |
| 241 |
IF (hi.GT.hihig .AND. iceFrac.LE.iceMaskmax) THEN |
| 242 |
Fbot=0. _d 0 |
| 243 |
ELSE |
| 244 |
Fbot=frzmlt |
| 245 |
ENDIF |
| 246 |
ELSE |
| 247 |
C !----------------------------------------------------------------- |
| 248 |
C ! melting conditions |
| 249 |
C !----------------------------------------------------------------- |
| 250 |
ustar = 5. _d -2 !for no currents |
| 251 |
C frictional velocity between ice and water |
| 252 |
ustar = SQRT(0.00536 _d 0*oceV2s) |
| 253 |
ustar=max(5. _d -3,ustar) |
| 254 |
cpchr =cpwater*rhosw*transcoef |
| 255 |
Fbot = cpchr*(Tf-oceTs)*ustar ! < 0 |
| 256 |
Fbot = max(Fbot,frzmlt) ! frzmlt < Fbot < 0 |
| 257 |
Fbot = min(Fbot,0. _d 0) |
| 258 |
ENDIF |
| 259 |
|
| 260 |
C mass of fresh water and salt initially present in ice |
| 261 |
mwater0 = rhos*hs + rhoi*hi |
| 262 |
msalt0 = rhoi*hi*saltice |
| 263 |
|
| 264 |
#ifdef ALLOW_DBUG_THSICE |
| 265 |
IF (dBug(i,j,bi,bj) ) WRITE(6,1020) |
| 266 |
& 'ThSI_CALC_TH: evpAtm, frzmlt, Fbot =', frwAtm(i,j),frzmlt,Fbot |
| 267 |
#endif |
| 268 |
|
| 269 |
C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----| |
| 270 |
|
| 271 |
C Compute energy available for melting/growth. |
| 272 |
|
| 273 |
IF (hi.LT.himin0) THEN |
| 274 |
C below a certain height, all energy goes to changing ice extent |
| 275 |
frace=1. _d 0 |
| 276 |
ELSE |
| 277 |
frace=frac_energy |
| 278 |
ENDIF |
| 279 |
IF (hi.GT.hihig) THEN |
| 280 |
C above certain height only melt from top |
| 281 |
frace=0. _d 0 |
| 282 |
ELSE |
| 283 |
frace=frac_energy |
| 284 |
ENDIF |
| 285 |
C force this when no ice fractionation |
| 286 |
IF (frac_energy.EQ.0. _d 0) frace=0. _d 0 |
| 287 |
|
| 288 |
c IF (Tsf .EQ. 0. _d 0 .AND. sHeating.GT.0. _d 0) THEN |
| 289 |
IF ( sHeating.GT.0. _d 0 ) THEN |
| 290 |
etop = (1. _d 0-frace)*sHeating * dt |
| 291 |
etope = frace*sHeating * dt |
| 292 |
ELSE |
| 293 |
etop = 0. _d 0 |
| 294 |
etope = 0. _d 0 |
| 295 |
C jmc: found few cases where Tsf=0 & sHeating < 0 : add this line to conserv energy: |
| 296 |
esurp = sHeating * dt |
| 297 |
ENDIF |
| 298 |
C-- flux at the base of sea-ice: |
| 299 |
C conduction H.flx= flxCnB (+ =down); oceanic turbulent H.flx= Fbot (+ =down). |
| 300 |
C- ==> energy available(+ => melt)= (flxCnB-Fbot)*dt |
| 301 |
c IF (frzmlt.LT.0. _d 0) THEN |
| 302 |
c ebot = (1. _d 0-frace)*(flxCnB-Fbot) * dt |
| 303 |
c ebote = frace*(flxCnB-Fbot) * dt |
| 304 |
c ELSE |
| 305 |
c ebot = (flxCnB-Fbot) * dt |
| 306 |
c ebote = 0. _d 0 |
| 307 |
c ENDIF |
| 308 |
C- original formulation(above): Loose energy when flxCnB < Fbot < 0 |
| 309 |
ebot = (flxCnB(i,j)-Fbot) * dt |
| 310 |
IF (ebot.GT.0. _d 0) THEN |
| 311 |
ebote = frace*ebot |
| 312 |
ebot = ebot-ebote |
| 313 |
ELSE |
| 314 |
ebote = 0. _d 0 |
| 315 |
ENDIF |
| 316 |
#ifdef ALLOW_DBUG_THSICE |
| 317 |
IF (dBug(i,j,bi,bj) ) WRITE(6,1020) |
| 318 |
& 'ThSI_CALC_TH: etop,etope,ebot,ebote=', etop,etope,ebot,ebote |
| 319 |
#endif |
| 320 |
|
| 321 |
C Initialize layer thicknesses. |
| 322 |
C Make sure internal ice temperatures do not exceed Tmlt. |
| 323 |
C If they do, then eliminate the layer. (Dont think this will happen |
| 324 |
C for reasonable values of i0.) |
| 325 |
|
| 326 |
hlyr = hi * rec_nlyr |
| 327 |
DO k = 1, nlyr |
| 328 |
hnew(k) = hlyr |
| 329 |
ENDDO |
| 330 |
|
| 331 |
C Top melt: snow, then ice. |
| 332 |
|
| 333 |
IF (etop .GT. 0. _d 0) THEN |
| 334 |
#ifdef ALLOW_AUTODIFF_TAMC |
| 335 |
CADJ STORE etop = comlev1_thsice_1, key=ikey_1 |
| 336 |
#endif |
| 337 |
IF (hs. gt. 0. _d 0) THEN |
| 338 |
rq = rhos * qsnow |
| 339 |
rqh = rq * hs |
| 340 |
IF (etop .LT. rqh) THEN |
| 341 |
hs = hs - etop/rq |
| 342 |
etop = 0. _d 0 |
| 343 |
ELSE |
| 344 |
etop = etop - rqh |
| 345 |
hs = 0. _d 0 |
| 346 |
ENDIF |
| 347 |
ENDIF |
| 348 |
|
| 349 |
DO k = 1, nlyr |
| 350 |
#ifdef ALLOW_AUTODIFF_TAMC |
| 351 |
ikey_2 = k |
| 352 |
& + nlyr*(i-1) |
| 353 |
& + nlyr*sNx*(j-1) |
| 354 |
& + nlyr*sNx*sNy*act1 |
| 355 |
& + nlyr*sNx*sNy*max1*act2 |
| 356 |
& + nlyr*sNx*sNy*max1*max2*act3 |
| 357 |
& + nlyr*sNx*sNy*max1*max2*max3*act4 |
| 358 |
#endif |
| 359 |
C-- |
| 360 |
#ifdef ALLOW_AUTODIFF_TAMC |
| 361 |
CADJ STORE etop = comlev1_thsice_2, key=ikey_2 |
| 362 |
CADJ STORE hnew(k) = comlev1_thsice_2, key=ikey_2 |
| 363 |
#endif |
| 364 |
IF (etop .GT. 0. _d 0) THEN |
| 365 |
rq = rhoi * qicen(k) |
| 366 |
rqh = rq * hnew(k) |
| 367 |
IF (etop .LT. rqh) THEN |
| 368 |
hnew(k) = hnew(k) - etop / rq |
| 369 |
etop = 0. _d 0 |
| 370 |
ELSE |
| 371 |
etop = etop - rqh |
| 372 |
hnew(k) = 0. _d 0 |
| 373 |
ENDIF |
| 374 |
ENDIF |
| 375 |
ENDDO |
| 376 |
ELSE |
| 377 |
etop=0. _d 0 |
| 378 |
ENDIF |
| 379 |
C If ice is gone and melting energy remains |
| 380 |
c IF (etop .GT. 0. _d 0) THEN |
| 381 |
c WRITE (6,*) 'QQ All ice melts from top ', i,j |
| 382 |
c hi=0. _d 0 |
| 383 |
c go to 200 |
| 384 |
c ENDIF |
| 385 |
|
| 386 |
|
| 387 |
C Bottom melt/growth. |
| 388 |
|
| 389 |
IF (ebot .LT. 0. _d 0) THEN |
| 390 |
C Compute enthalpy of new ice growing at bottom surface. |
| 391 |
qbot = -cpice *Tf + Lfresh |
| 392 |
dhi = -ebot / (qbot * rhoi) |
| 393 |
ebot = 0. _d 0 |
| 394 |
cph k = nlyr |
| 395 |
#ifdef ALLOW_AUTODIFF_TAMC |
| 396 |
CADJ STORE hnew(:) = comlev1_thsice_1, key=ikey_1 |
| 397 |
CADJ STORE qicen(:) = comlev1_thsice_1, key=ikey_1 |
| 398 |
#endif |
| 399 |
qicen(nlyr) = (hnew(nlyr)*qicen(nlyr)+dhi*qbot) / |
| 400 |
& (hnew(nlyr)+dhi) |
| 401 |
hnew(nlyr) = hnew(nlyr) + dhi |
| 402 |
ELSE |
| 403 |
DO k = nlyr, 1, -1 |
| 404 |
#ifdef ALLOW_AUTODIFF_TAMC |
| 405 |
ikey_2 = (nlyr-k+1) |
| 406 |
& + nlyr*(i-1) |
| 407 |
& + nlyr*sNx*(j-1) |
| 408 |
& + nlyr*sNx*sNy*act1 |
| 409 |
& + nlyr*sNx*sNy*max1*act2 |
| 410 |
& + nlyr*sNx*sNy*max1*max2*act3 |
| 411 |
& + nlyr*sNx*sNy*max1*max2*max3*act4 |
| 412 |
#endif |
| 413 |
C-- |
| 414 |
#ifdef ALLOW_AUTODIFF_TAMC |
| 415 |
CADJ STORE ebot = comlev1_thsice_2, key=ikey_2 |
| 416 |
CADJ STORE hnew(k) = comlev1_thsice_2, key=ikey_2 |
| 417 |
CADJ STORE qicen(k) = comlev1_thsice_2, key=ikey_2 |
| 418 |
#endif |
| 419 |
IF (ebot.GT.0. _d 0 .AND. hnew(k).GT.0. _d 0) THEN |
| 420 |
rq = rhoi * qicen(k) |
| 421 |
rqh = rq * hnew(k) |
| 422 |
IF (ebot .LT. rqh) THEN |
| 423 |
hnew(k) = hnew(k) - ebot / rq |
| 424 |
ebot = 0. _d 0 |
| 425 |
ELSE |
| 426 |
ebot = ebot - rqh |
| 427 |
hnew(k) = 0. _d 0 |
| 428 |
ENDIF |
| 429 |
ENDIF |
| 430 |
ENDDO |
| 431 |
|
| 432 |
C If ice melts completely and snow is left, remove the snow with |
| 433 |
C energy from the mixed layer |
| 434 |
|
| 435 |
IF (ebot.GT.0. _d 0 .AND. hs.GT.0. _d 0) THEN |
| 436 |
rq = rhos * qsnow |
| 437 |
rqh = rq * hs |
| 438 |
IF (ebot .LT. rqh) THEN |
| 439 |
hs = hs - ebot / rq |
| 440 |
ebot = 0. _d 0 |
| 441 |
ELSE |
| 442 |
ebot = ebot - rqh |
| 443 |
hs = 0. _d 0 |
| 444 |
ENDIF |
| 445 |
ENDIF |
| 446 |
c IF (ebot .GT. 0. _d 0) THEN |
| 447 |
c IF (dBug) WRITE(6,*) 'All ice (& snow) melts from bottom' |
| 448 |
c hi=0. _d 0 |
| 449 |
c go to 200 |
| 450 |
c ENDIF |
| 451 |
ENDIF |
| 452 |
|
| 453 |
C Compute new total ice thickness. |
| 454 |
hi = 0. _d 0 |
| 455 |
DO k = 1, nlyr |
| 456 |
hi = hi + hnew(k) |
| 457 |
ENDDO |
| 458 |
#ifdef ALLOW_DBUG_THSICE |
| 459 |
IF (dBug(i,j,bi,bj) ) WRITE(6,1020) |
| 460 |
& 'ThSI_CALC_TH: etop, ebot, hi, hs =', etop, ebot, hi, hs |
| 461 |
#endif |
| 462 |
|
| 463 |
C If hi < himin, melt the ice. |
| 464 |
IF ( hi.LT.himin .AND. (hi+hs).GT.0. _d 0 ) THEN |
| 465 |
esurp = esurp - rhos*qsnow*hs |
| 466 |
DO k = 1, nlyr |
| 467 |
esurp = esurp - rhoi*qicen(k)*hnew(k) |
| 468 |
ENDDO |
| 469 |
hi = 0. _d 0 |
| 470 |
hs = 0. _d 0 |
| 471 |
Tsf=0. _d 0 |
| 472 |
iceFrac = 0. _d 0 |
| 473 |
DO k = 1, nlyr |
| 474 |
qicen(k) = 0. _d 0 |
| 475 |
ENDDO |
| 476 |
#ifdef ALLOW_DBUG_THSICE |
| 477 |
IF (dBug(i,j,bi,bj) ) WRITE(6,1020) |
| 478 |
& 'ThSI_CALC_TH: -1 : esurp=',esurp |
| 479 |
#endif |
| 480 |
ENDIF |
| 481 |
|
| 482 |
C-- do a mass-budget of sea-ice to compute "fresh" = the fresh-water flux |
| 483 |
C that is returned to the ocean ; needs to be done before snow/evap |
| 484 |
fresh = (mwater0 - (rhos*hs + rhoi*hi))/dt |
| 485 |
|
| 486 |
IF ( hi .LE. 0. _d 0 ) THEN |
| 487 |
C- return snow to the ocean (account for Latent heat of freezing) |
| 488 |
fresh = fresh + snowPr |
| 489 |
qleft = qleft - snowPr*Lfresh |
| 490 |
|
| 491 |
ELSE |
| 492 |
C- else: hi > 0 |
| 493 |
|
| 494 |
C Let it snow |
| 495 |
|
| 496 |
hs = hs + dt*snowPr/rhos |
| 497 |
|
| 498 |
C If ice evap is used to sublimate surface snow/ice or |
| 499 |
C if no ice pass on to ocean |
| 500 |
#ifdef ALLOW_AUTODIFF_TAMC |
| 501 |
CADJ STORE evap = comlev1_thsice_1, key=ikey_1 |
| 502 |
CADJ STORE hs = comlev1_thsice_1, key=ikey_1 |
| 503 |
#endif |
| 504 |
IF (hs.GT.0. _d 0) THEN |
| 505 |
IF (evap/rhos *dt.GT.hs) THEN |
| 506 |
evap=evap-hs*rhos/dt |
| 507 |
hs=0. _d 0 |
| 508 |
ELSE |
| 509 |
hs = hs - evap/rhos *dt |
| 510 |
evap=0. _d 0 |
| 511 |
ENDIF |
| 512 |
ENDIF |
| 513 |
#ifdef ALLOW_AUTODIFF_TAMC |
| 514 |
CADJ STORE evap = comlev1_thsice_1, key=ikey_1 |
| 515 |
CADJ STORE hi = comlev1_thsice_1, key=ikey_1 |
| 516 |
CADJ STORE hnew(:) = comlev1_thsice_1, key=ikey_1 |
| 517 |
CADJ STORE qicen(:) = comlev1_thsice_1, key=ikey_1 |
| 518 |
#endif |
| 519 |
IF (hi.GT.0. _d 0.AND.evap.GT.0. _d 0) THEN |
| 520 |
DO k = 1, nlyr |
| 521 |
#ifdef ALLOW_AUTODIFF_TAMC |
| 522 |
ikey_2 = k |
| 523 |
& + nlyr*(i-1) |
| 524 |
& + nlyr*sNx*(j-1) |
| 525 |
& + nlyr*sNx*sNy*act1 |
| 526 |
& + nlyr*sNx*sNy*max1*act2 |
| 527 |
& + nlyr*sNx*sNy*max1*max2*act3 |
| 528 |
& + nlyr*sNx*sNy*max1*max2*max3*act4 |
| 529 |
#endif |
| 530 |
C-- |
| 531 |
#ifdef ALLOW_AUTODIFF_TAMC |
| 532 |
CADJ STORE evap = comlev1_thsice_2, key=ikey_2 |
| 533 |
CADJ STORE hnew(k) = comlev1_thsice_2, key=ikey_2 |
| 534 |
CADJ STORE qicen(k) = comlev1_thsice_2, key=ikey_2 |
| 535 |
#endif |
| 536 |
IF (evap .GT. 0. _d 0) THEN |
| 537 |
C-- original scheme, does not care about ice temp. |
| 538 |
C- this can produce small error (< 1.W/m2) in the Energy budget |
| 539 |
c IF (evap/rhoi *dt.GT.hnew(k)) THEN |
| 540 |
c evap=evap-hnew(k)*rhoi/dt |
| 541 |
c hnew(k)=0. _d 0 |
| 542 |
c ELSE |
| 543 |
c hnew(k) = hnew(k) - evap/rhoi *dt |
| 544 |
c evap=0. _d 0 |
| 545 |
c ENDIF |
| 546 |
C-- modified scheme. taking into account Ice enthalpy |
| 547 |
dhi = evap/rhoi*dt |
| 548 |
IF (dhi.GE.hnew(k)) THEN |
| 549 |
evap=evap-hnew(k)*rhoi/dt |
| 550 |
esurp = esurp - hnew(k)*rhoi*(qicen(k)-Lfresh) |
| 551 |
hnew(k)=0. _d 0 |
| 552 |
ELSE |
| 553 |
#ifdef ALLOW_AUTODIFF_TAMC |
| 554 |
CADJ STORE hnew(k) = comlev1_thsice_2, key=ikey_2 |
| 555 |
#endif |
| 556 |
hq = hnew(k)*qicen(k)-dhi*Lfresh |
| 557 |
hnew(k) = hnew(k) - dhi |
| 558 |
qicen(k)=hq/hnew(k) |
| 559 |
evap=0. _d 0 |
| 560 |
ENDIF |
| 561 |
C------- |
| 562 |
ENDIF |
| 563 |
ENDDO |
| 564 |
ENDIF |
| 565 |
c IF (evap .GT. 0. _d 0) THEN |
| 566 |
c WRITE (6,*) 'BB All ice sublimates', i,j |
| 567 |
c hi=0. _d 0 |
| 568 |
c go to 200 |
| 569 |
c ENDIF |
| 570 |
|
| 571 |
C Compute new total ice thickness. |
| 572 |
|
| 573 |
hi = 0. _d 0 |
| 574 |
DO k = 1, nlyr |
| 575 |
hi = hi + hnew(k) |
| 576 |
ENDDO |
| 577 |
|
| 578 |
C If hi < himin, melt the ice. |
| 579 |
IF ( hi.GT.0. _d 0 .AND. hi.LT.himin ) THEN |
| 580 |
fresh = fresh + (rhos*hs + rhoi*hi)/dt |
| 581 |
esurp = esurp - rhos*qsnow*hs |
| 582 |
DO k = 1, nlyr |
| 583 |
esurp = esurp - rhoi*qicen(k)*hnew(k) |
| 584 |
ENDDO |
| 585 |
hi = 0. _d 0 |
| 586 |
hs = 0. _d 0 |
| 587 |
Tsf=0. _d 0 |
| 588 |
iceFrac = 0. _d 0 |
| 589 |
DO k = 1, nlyr |
| 590 |
qicen(k) = 0. _d 0 |
| 591 |
ENDDO |
| 592 |
#ifdef ALLOW_DBUG_THSICE |
| 593 |
IF (dBug(i,j,bi,bj) ) WRITE(6,1020) |
| 594 |
& 'ThSI_CALC_TH: -2 : esurp,fresh=', esurp, fresh |
| 595 |
#endif |
| 596 |
ENDIF |
| 597 |
|
| 598 |
C- else hi > 0: end |
| 599 |
ENDIF |
| 600 |
|
| 601 |
IF ( hi .GT. 0. _d 0 ) THEN |
| 602 |
|
| 603 |
C If there is enough snow to lower the ice/snow interface below |
| 604 |
C freeboard, convert enough snow to ice to bring the interface back |
| 605 |
C to sea-level. Adjust enthalpy of top ice layer accordingly. |
| 606 |
|
| 607 |
#ifdef ALLOW_AUTODIFF_TAMC |
| 608 |
CADJ STORE hi = comlev1_thsice_1, key=ikey_1 |
| 609 |
CADJ STORE hs = comlev1_thsice_1, key=ikey_1 |
| 610 |
CADJ STORE hnew(:) = comlev1_thsice_1, key=ikey_1 |
| 611 |
CADJ STORE qicen(:) = comlev1_thsice_1, key=ikey_1 |
| 612 |
#endif |
| 613 |
IF ( hs .GT. hi*rhoiw/rhos ) THEN |
| 614 |
cBB WRITE (6,*) 'Freeboard adjusts' |
| 615 |
dhi = (hs * rhos - hi * rhoiw) / rhosw |
| 616 |
dhs = dhi * rhoi / rhos |
| 617 |
#ifdef ALLOW_AUTODIFF_TAMC |
| 618 |
CADJ STORE hnew(:) = comlev1_thsice_1, key=ikey_1 |
| 619 |
#endif |
| 620 |
rqh = rhoi*qicen(1)*hnew(1) + rhos*qsnow*dhs |
| 621 |
hnew(1) = hnew(1) + dhi |
| 622 |
qicen(1) = rqh / (rhoi*hnew(1)) |
| 623 |
hi = hi + dhi |
| 624 |
hs = hs - dhs |
| 625 |
ENDIF |
| 626 |
|
| 627 |
|
| 628 |
C limit ice height |
| 629 |
C- NOTE: this part does not conserve Energy ; |
| 630 |
C but surplus of fresh water and salt are taken into account. |
| 631 |
IF (hi.GT.hiMax) THEN |
| 632 |
cBB print*,'BBerr, hi>hiMax',i,j,hi |
| 633 |
chi=hi-hiMax |
| 634 |
DO k=1,nlyr |
| 635 |
hnew(k)=hnew(k)-chi/2. _d 0 |
| 636 |
ENDDO |
| 637 |
fresh = fresh + chi*rhoi/dt |
| 638 |
ENDIF |
| 639 |
IF (hs.GT.hsMax) THEN |
| 640 |
c print*,'BBerr, hs>hsMax',i,j,hs |
| 641 |
chs=hs-hsMax |
| 642 |
hs=hsMax |
| 643 |
fresh = fresh + chs*rhos/dt |
| 644 |
ENDIF |
| 645 |
|
| 646 |
C Compute new total ice thickness. |
| 647 |
|
| 648 |
hi = 0. _d 0 |
| 649 |
DO k = 1, nlyr |
| 650 |
hi = hi + hnew(k) |
| 651 |
ENDDO |
| 652 |
|
| 653 |
#ifdef ALLOW_DBUG_THSICE |
| 654 |
IF (dBug(i,j,bi,bj) ) WRITE(6,1020) |
| 655 |
& 'ThSI_CALC_TH: b-Winton: hnew, qice =', hnew, qicen |
| 656 |
#endif |
| 657 |
|
| 658 |
hlyr = hi * rec_nlyr |
| 659 |
CALL THSICE_RESHAPE_LAYERS( |
| 660 |
U qicen, |
| 661 |
I hlyr, hnew, myThid ) |
| 662 |
|
| 663 |
#ifdef ALLOW_DBUG_THSICE |
| 664 |
IF (dBug(i,j,bi,bj) ) WRITE(6,1020) |
| 665 |
& 'ThSI_CALC_TH: iceFrac,hi, qtot, hs =', iceFrac,hi, |
| 666 |
& (qicen(1)+qicen(2))*0.5, hs |
| 667 |
#endif |
| 668 |
|
| 669 |
C- if hi > 0 : end |
| 670 |
ENDIF |
| 671 |
200 CONTINUE |
| 672 |
|
| 673 |
C- Compute surplus energy left over from melting. |
| 674 |
|
| 675 |
IF (hi.LE.0. _d 0) iceFrac=0. _d 0 |
| 676 |
|
| 677 |
C.. heat fluxes left over for ocean |
| 678 |
qleft = qleft + (Fbot+(esurp+etop+ebot)/dt) |
| 679 |
#ifdef ALLOW_DBUG_THSICE |
| 680 |
IF (dBug(i,j,bi,bj) ) WRITE(6,1020) |
| 681 |
& 'ThSI_CALC_TH: [esurp,etop+ebot]/dt =',esurp/dt,etop/dt,ebot/dt |
| 682 |
#endif |
| 683 |
|
| 684 |
C-- Evaporation left to the ocean : |
| 685 |
fresh = fresh - evap |
| 686 |
C- Correct Atmos. fluxes for this different latent heat: |
| 687 |
C evap was computed over freezing surf.(Tsf<0), latent heat = Lvap+Lfresh |
| 688 |
C but should be Lvap only for the fraction "evap" that is left to the ocean. |
| 689 |
qleft = qleft + evap*Lfresh |
| 690 |
|
| 691 |
C fresh and salt fluxes |
| 692 |
c fresh = (mwater0 - (rhos*(hs) + rhoi*(hi)))/dt-evap |
| 693 |
c fsalt = (msalt0 - rhoi*hi*saltice)/35. _d 0/dt ! for same units as fresh |
| 694 |
C note (jmc): fresh is computed from a sea-ice mass budget that already |
| 695 |
C contains, at this point, snow & evaporation (of snow & ice) |
| 696 |
C but are not meant to be part of ice/ocean fresh-water flux. |
| 697 |
C fix: a) like below or b) by making the budget before snow/evap is added |
| 698 |
c fresh = (mwater0 - (rhos*(hs) + rhoi*(hi)))/dt |
| 699 |
c & + snow(i,j,bi,bj)*rhos - frwAtm |
| 700 |
fsalt(i,j) = (msalt0 - rhoi*hi*saltice)/dt |
| 701 |
|
| 702 |
#ifdef ALLOW_DBUG_THSICE |
| 703 |
IF (dBug(i,j,bi,bj) ) THEN |
| 704 |
WRITE(6,1020)'ThSI_CALC_TH:dH2O,Ev[kg],fresh,fsalt', |
| 705 |
& (mwater0-(rhos*hs+rhoi*hi))/dt,evap,fresh,fsalt(i,j) |
| 706 |
WRITE(6,1020)'ThSI_CALC_TH: Qleft,Fbot,extend/dt =', |
| 707 |
& Qleft,Fbot,(etope+ebote)/dt |
| 708 |
ENDIF |
| 709 |
#endif |
| 710 |
|
| 711 |
C-- add remaining liquid Precip (rain+RunOff) directly to ocean: |
| 712 |
fresh = fresh + (prcAtm(i,j)-snowPr) |
| 713 |
|
| 714 |
C-- note: at this point, iceFrac has not been changed (unless reset to zero) |
| 715 |
C and it can only be reduced by lateral melting in the following part: |
| 716 |
|
| 717 |
C calculate extent changes |
| 718 |
extend=etope+ebote |
| 719 |
IF (iceFrac.GT.0. _d 0.AND.extend.GT.0. _d 0) THEN |
| 720 |
rq = rhoi * 0.5 _d 0*(qicen(1)+qicen(2)) |
| 721 |
rs = rhos * qsnow |
| 722 |
rqh = rq * hi + rs * hs |
| 723 |
freshe=(rhos*hs+rhoi*hi)/dt |
| 724 |
salte=(rhoi*hi*saltice)/dt |
| 725 |
IF (extend .LT. rqh) THEN |
| 726 |
iceFrac=(1. _d 0-extend/rqh)*iceFrac |
| 727 |
fresh=fresh+extend/rqh*freshe |
| 728 |
fsalt(i,j)=fsalt(i,j)+extend/rqh*salte |
| 729 |
ELSE |
| 730 |
iceFrac=0. _d 0 |
| 731 |
hi=0. _d 0 |
| 732 |
hs=0. _d 0 |
| 733 |
qleft=qleft+(extend-rqh)/dt |
| 734 |
fresh=fresh+freshe |
| 735 |
fsalt(i,j)=fsalt(i,j)+salte |
| 736 |
ENDIF |
| 737 |
ELSEIF (extend.GT.0. _d 0) THEN |
| 738 |
qleft=qleft+extend/dt |
| 739 |
ENDIF |
| 740 |
|
| 741 |
C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----| |
| 742 |
C-- Update output variables : |
| 743 |
|
| 744 |
C- Diagnostic of Atmos. fresh water flux (E-P) over sea-ice : |
| 745 |
C substract precip from Evap (<- stored in frwAtm array) |
| 746 |
frwAtm(i,j) = frwAtm(i,j) - prcAtm(i,j) |
| 747 |
|
| 748 |
C- update Mixed-Layer Freezing potential heat flux by substracting the |
| 749 |
C part which has already been accounted for (Fbot): |
| 750 |
fzMlOc(i,j) = frzmlt - Fbot*iceMask(i,j) |
| 751 |
|
| 752 |
C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----| |
| 753 |
#ifdef ALLOW_DBUG_THSICE |
| 754 |
IF (dBug(i,j,bi,bj) ) WRITE(6,1020) |
| 755 |
& 'ThSI_CALC_TH: iceFrac,flx2oc,fsalt,frw2oc=', |
| 756 |
& iceFrac, qleft, fsalt(i,j), fresh |
| 757 |
#endif |
| 758 |
#ifdef CHECK_ENERGY_CONSERV |
| 759 |
CALL THSICE_CHECK_CONSERV( dBugFlag, i, j, bi, bj, 0, |
| 760 |
I iceMask(i,j), iceFrac, hi, hs, qicen, |
| 761 |
I qleft, fresh, fsalt, |
| 762 |
I myTime, myIter, myThid ) |
| 763 |
#endif /* CHECK_ENERGY_CONSERV */ |
| 764 |
C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----| |
| 765 |
C-- Update Sea-Ice state output: |
| 766 |
icFrac(i,j) = iceFrac |
| 767 |
hIce(i,j) = hi |
| 768 |
hSnow(i,j ) = hs |
| 769 |
tSrf(i,j) = Tsf |
| 770 |
qIc1(i,j) = qicen(1) |
| 771 |
qIc2(i,j) = qicen(2) |
| 772 |
C-- Update oceanic flux output: |
| 773 |
flx2oc(i,j) = qleft |
| 774 |
frw2oc(i,j) = fresh |
| 775 |
c fsalt(i,j) = fsalt |
| 776 |
ENDIF |
| 777 |
ENDDO |
| 778 |
ENDDO |
| 779 |
#endif /* ALLOW_THSICE */ |
| 780 |
|
| 781 |
C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----| |
| 782 |
|
| 783 |
RETURN |
| 784 |
END |
Parent Directory
| 
Revision Log
| 
Revision Graph