| 1 |
C $Header: /u/gcmpack/MITgcm/pkg/seaice/seaice_budget_ice.F,v 1.3 2006/12/19 18:57:09 dimitri Exp $ |
| 2 |
C $Name: $ |
| 3 |
|
| 4 |
#include "SEAICE_OPTIONS.h" |
| 5 |
|
| 6 |
CStartOfInterface |
| 7 |
SUBROUTINE SEAICE_BUDGET_ICE( |
| 8 |
I UG, HICE_ACTUAL, HSNOW_ACTUAL, |
| 9 |
U TSURF, |
| 10 |
O F_io_net,F_ia_net,F_ia, IcePenetratingShortwaveFlux, |
| 11 |
I bi, bj ) |
| 12 |
C /================================================================\ |
| 13 |
C | SUBROUTINE seaice_budget_ice | |
| 14 |
C | o Calculate ice growth rate, surface fluxes and temperature of | |
| 15 |
C | ice surface. | |
| 16 |
C | see Hibler, MWR, 108, 1943-1973, 1980 | |
| 17 |
C |================================================================| |
| 18 |
C \================================================================/ |
| 19 |
IMPLICIT NONE |
| 20 |
|
| 21 |
C === Global variables === |
| 22 |
#include "SIZE.h" |
| 23 |
#include "EEPARAMS.h" |
| 24 |
#include "FFIELDS.h" |
| 25 |
#include "SEAICE_PARAMS.h" |
| 26 |
#include "SEAICE_FFIELDS.h" |
| 27 |
#ifdef SEAICE_VARIABLE_FREEZING_POINT |
| 28 |
#include "DYNVARS.h" |
| 29 |
#endif /* SEAICE_VARIABLE_FREEZING_POINT */ |
| 30 |
|
| 31 |
C === Routine arguments === |
| 32 |
C INPUT: |
| 33 |
C UG :: thermal wind of atmosphere |
| 34 |
C TSURF :: surface temperature of ice in Kelvin, updated |
| 35 |
C HICE_ACTUAL :: (actual) ice thickness with upper and lower limit |
| 36 |
C HSNOW_ACTUAL :: actual snow thickness |
| 37 |
C bi,bj :: loop indices |
| 38 |
C OUTPUT: |
| 39 |
C netHeatFlux :: net heat flux under ice = growth rate |
| 40 |
C IcePenetratingShortwaveFlux :: short wave heat flux under ice |
| 41 |
_RL UG (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
| 42 |
_RL TSURF (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
| 43 |
_RL HICE_ACTUAL (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
| 44 |
_RL HSNOW_ACTUAL (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
| 45 |
|
| 46 |
_RL F_ia (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
| 47 |
_RL F_io_net (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
| 48 |
_RL F_ia_net (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
| 49 |
|
| 50 |
_RL F_swi (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
| 51 |
_RL F_lwd (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
| 52 |
_RL F_lwu (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
| 53 |
_RL F_lh (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
| 54 |
_RL F_sens (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
| 55 |
_RL F_c (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
| 56 |
_RL qhice_mm (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
| 57 |
|
| 58 |
_RL IcePenetratingShortwaveFlux (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
| 59 |
_RL AbsorbedShortwaveFlux (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
| 60 |
_RL IcePenetratingShortwaveFluxFraction |
| 61 |
& (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
| 62 |
|
| 63 |
INTEGER bi, bj |
| 64 |
INTEGER KOPEN |
| 65 |
|
| 66 |
C === Local variables === |
| 67 |
C i,j - Loop counters |
| 68 |
INTEGER i, j |
| 69 |
INTEGER ITER |
| 70 |
_RL QS1, C1, C2, C3, C4, C5, TB, D1, D1I, D3,IAN1 |
| 71 |
_RL TMELT, TMELTP, XKI, XKS, HCUT, ASNOW, XIO |
| 72 |
C effective conductivity of combined ice and snow |
| 73 |
_RL effConduct |
| 74 |
C specific humidity at ice surface |
| 75 |
_RL mm_pi,mm_log10pi,dqhice_dTice |
| 76 |
|
| 77 |
C powers of temperature |
| 78 |
_RL t1, t2, t3, t4 |
| 79 |
|
| 80 |
C local copies of global variables |
| 81 |
_RL tsurfLoc (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
| 82 |
_RL atempLoc (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
| 83 |
_RL lwdownLoc (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
| 84 |
_RL ALB (1-OLx:sNx+OLx,1-OLy:sNy+OLy) |
| 85 |
_RL tsurfLocOld |
| 86 |
|
| 87 |
c Ian Saturation Vapor Pressure |
| 88 |
_RL aa1,aa2,bb1,bb2,Ppascals,cc0,cc1,cc2,cc3t,dFiDTs1 |
| 89 |
|
| 90 |
aa1 = 2663.5 |
| 91 |
aa2 = 12.537 |
| 92 |
bb1 = 0.622 |
| 93 |
bb2 = 1.0 - bb1 |
| 94 |
Ppascals = 1000.*100. |
| 95 |
cc0 = 10**aa2 |
| 96 |
cc1 = cc0*aa1*bb1*Ppascals*log(10.0) |
| 97 |
cc2 = cc0*bb2 |
| 98 |
|
| 99 |
C FREEZING TEMPERATURE OF SEAWATER |
| 100 |
TB=273.15 _d + 00 - 1.96 _d + 00 |
| 101 |
C SENSIBLE HEAT CONSTANT |
| 102 |
D1=SEAICE_sensHeat |
| 103 |
C ICE LATENT HEAT CONSTANT |
| 104 |
D1I=SEAICE_latentIce |
| 105 |
C STEFAN BOLTZMAN CONSTANT TIMES 0.97 EMISSIVITY |
| 106 |
D3=SEAICE_emissivity |
| 107 |
C MELTING TEMPERATURE OF ICE |
| 108 |
TMELT=273.15 _d +00 |
| 109 |
|
| 110 |
C ICE CONDUCTIVITY |
| 111 |
XKI=2.0340 |
| 112 |
C SNOW CONDUCTIVITY |
| 113 |
XKS=SEAICE_snowConduct |
| 114 |
C CUTOFF SNOW THICKNESS |
| 115 |
HCUT=SEAICE_snowThick |
| 116 |
C PENETRATION SHORTWAVE RADIATION FACTOR |
| 117 |
XIO=SEAICE_shortwave |
| 118 |
|
| 119 |
DO J=1,sNy |
| 120 |
DO I=1,sNx |
| 121 |
IcePenetratingShortwaveFlux (I,J) = 0. _d 0 |
| 122 |
IcePenetratingShortwaveFluxFraction (I,J) = 0. _d 0 |
| 123 |
AbsorbedShortwaveFlux (I,J) = 0. _d 0 |
| 124 |
|
| 125 |
qhice_mm (I,J) = 0.0 _d 0 |
| 126 |
F_ia (I,J) = 0.0 _d 0 |
| 127 |
F_io_net (I,J) = 0.0 _d 0 |
| 128 |
F_ia_net (I,J) = 0.0 _d 0 |
| 129 |
|
| 130 |
F_swi (I,J) = 0.0 _d 0 |
| 131 |
F_lwd (I,J) = 0.0 _d 0 |
| 132 |
F_lwu (I,J) = 0.0 _d 0 |
| 133 |
F_lh (I,J) = 0.0 _d 0 |
| 134 |
F_sens (I,J) = 0.0 _d 0 |
| 135 |
|
| 136 |
c set the surface temperature to zero if there is no ice there. |
| 137 |
IF (HICE_ACTUAL(I,J) .NE. 0.0) THEN |
| 138 |
tsurfLoc (I,J) = MIN(TMELT, TSURF(I,J,bi,bj)) |
| 139 |
ELSE |
| 140 |
tsurfLoc(I,J) = TMELT |
| 141 |
ENDIF |
| 142 |
|
| 143 |
TSURF(I,J,bi,bj) = tsurfLoc(I,J) |
| 144 |
|
| 145 |
atempLoc (I,J) = MAX(TMELT + MIN_ATEMP,ATEMP(I,J,bi,bj)) |
| 146 |
lwdownLoc(I,J) = LWDOWN(I,J,bi,bj) |
| 147 |
|
| 148 |
ENDDO |
| 149 |
ENDDO |
| 150 |
|
| 151 |
C COME HERE AT START OF ITERATION |
| 152 |
|
| 153 |
DO J=1,sNy |
| 154 |
DO I=1,sNx |
| 155 |
|
| 156 |
IF (HICE_ACTUAL(I,J) .NE. 0.0) THEN |
| 157 |
|
| 158 |
C DECIDE ON ALBEDO |
| 159 |
IF (tsurfLoc(I,J) .GE. TMELT) THEN |
| 160 |
IF (HSNOW_ACTUAL(I,J) .EQ. 0.0) THEN |
| 161 |
ALB(I,J) = SEAICE_wetIceAlb |
| 162 |
ELSE ! some snow |
| 163 |
ALB(I,J) = SEAICE_wetSnowAlb |
| 164 |
ENDIF |
| 165 |
ELSE ! no surface melting |
| 166 |
IF (HSNOW_ACTUAL(I,J) .EQ. 0.0) THEN |
| 167 |
ALB(I,J) = SEAICE_dryIceAlb |
| 168 |
ELSE ! some snow |
| 169 |
ALB(I,J) = SEAICE_drySnowAlb |
| 170 |
ENDIF |
| 171 |
ENDIF |
| 172 |
|
| 173 |
F_lwd(I,J) = - 0.97 _d 0 * lwdownLoc(I,J) |
| 174 |
|
| 175 |
IF (HSNOW_ACTUAL(I,J) .GT. 0.0) THEN |
| 176 |
IcePenetratingShortwaveFluxFraction(I,J) = ZERO |
| 177 |
ELSE |
| 178 |
IcePenetratingShortwaveFluxFraction(I,J) = |
| 179 |
& XIO*EXP(-1.5 _d 0 * HICE_ACTUAL(I,J)) |
| 180 |
ENDIF |
| 181 |
|
| 182 |
AbsorbedShortwaveFlux(I,J) = -(ONE - ALB(I,J))* |
| 183 |
& (1.0 - IcePenetratingShortwaveFluxFraction(I,J)) |
| 184 |
& *SWDOWN(I,J,bi,bj) |
| 185 |
|
| 186 |
IcePenetratingShortwaveFlux(I,J) = -(ONE - ALB(I,J))* |
| 187 |
& IcePenetratingShortwaveFluxFraction(I,J) |
| 188 |
& *SWDOWN(I,J,bi,bj) |
| 189 |
|
| 190 |
F_swi(I,J) = AbsorbedShortwaveFlux(I,J) |
| 191 |
|
| 192 |
c set a min ice as 5 cm to limit arbitrarily large conduction. |
| 193 |
HICE_ACTUAL(I,J) = max(HICE_ACTUAL(I,J),0.05) |
| 194 |
|
| 195 |
effConduct = XKI * XKS / |
| 196 |
& (XKS * HICE_ACTUAL(I,J) + XKI * HSNOW_ACTUAL(I,J)) |
| 197 |
|
| 198 |
DO ITER=1,IMAX_TICE |
| 199 |
|
| 200 |
t1 = tsurfLoc(I,J) |
| 201 |
t2 = t1*t1 |
| 202 |
t3 = t2*t1 |
| 203 |
t4 = t2*t2 |
| 204 |
|
| 205 |
tsurfLocOld = t1 |
| 206 |
|
| 207 |
c log 10 of the sat vap pressure |
| 208 |
mm_log10pi = -aa1 / t1 + aa2 |
| 209 |
c saturation vapor pressure |
| 210 |
mm_pi = 10**(mm_log10pi) |
| 211 |
c over ice specific humidity |
| 212 |
qhice_mm(I,J) = bb1*mm_pi / (Ppascals - (1.0 - bb1) * mm_pi) |
| 213 |
|
| 214 |
c constant for sat vap pressure derivative w.r.t tice |
| 215 |
cc3t = 10**(aa1 / t1) |
| 216 |
c the actual derivative |
| 217 |
dqhice_dTice = cc1 * cc3t /( (cc2-cc3t*Ppascals)**2 * t2) |
| 218 |
|
| 219 |
c the full derivative |
| 220 |
dFiDTs1 = 4.0 * D3*t3 + effConduct + D1*UG(I,J) + |
| 221 |
& D1I*UG(I,J)*dqhice_dTice |
| 222 |
|
| 223 |
|
| 224 |
F_lh(I,J) = D1I * UG(I,J) * (qhice_mm(I,J)-AQH(I,J,bi,bj)) |
| 225 |
F_c(I,J) = -effConduct * (TB - t1) |
| 226 |
F_lwu(I,J) = t4 * D3 |
| 227 |
F_sens(I,J) = D1 * UG(I,J) * (t1 - atempLoc(I,J)) |
| 228 |
|
| 229 |
F_ia(I,J) = F_lwd(I,J) + F_swi(I,J) + F_lwu(I,J) + |
| 230 |
& F_c(I,J) + F_sens(I,J) + F_lh(I,J) |
| 231 |
|
| 232 |
tsurfLoc(I,J) = tsurfLoc(I,J) - F_ia(I,J) / dFiDTs1 |
| 233 |
|
| 234 |
#ifdef SEAICE_DEBUG |
| 235 |
print *,'ice-iter tsurfLc,|dif|', I,J, ITER,tsurfLoc(I,J), |
| 236 |
& log10(abs(tsurfLoc(I,J) - tsurfLocOld)) |
| 237 |
#endif |
| 238 |
ENDDO !/* Iterations */ |
| 239 |
|
| 240 |
tsurfLoc(I,J) = MIN(tsurfLoc(I,J),TMELT) |
| 241 |
TSURF(I,J,bi,bj) = tsurfLoc(I,J) |
| 242 |
|
| 243 |
t1 = tsurfLoc(I,J) |
| 244 |
t2 = t1*t1 |
| 245 |
t3 = t2*t1 |
| 246 |
t4 = t2*t2 |
| 247 |
|
| 248 |
c log 10 of the sat vap pressure |
| 249 |
mm_log10pi = -aa1 / t1 + aa2 |
| 250 |
c saturation vapor pressure |
| 251 |
mm_pi = 10**(mm_log10pi) |
| 252 |
c over ice specific humidity |
| 253 |
qhice_mm(I,J) = bb1*mm_pi / (Ppascals - (1.0 - bb1) * mm_pi) |
| 254 |
|
| 255 |
F_lh(I,J) = D1I * UG(I,J) * (qhice_mm(I,J)-AQH(I,J,bi,bj)) |
| 256 |
F_c(I,J) = -effConduct * (TB - t1) |
| 257 |
F_lwu(I,J) = t4 * D3 |
| 258 |
F_sens(I,J) = D1 * UG(I,J) * (t1 - atempLoc(I,J)) |
| 259 |
|
| 260 |
c exlude conductive flux, the actual flux with the atmosphere. |
| 261 |
F_ia(I,J) = F_lwd(I,J) + F_swi(I,J) + F_lwu(I,J) + |
| 262 |
& F_sens(I,J) + F_lh(I,J) |
| 263 |
|
| 264 |
IF (F_c(I,J) .LT. 0.0) THEN |
| 265 |
F_io_net(I,J) = -F_c(I,J) |
| 266 |
F_ia_net(I,J) = 0.0 |
| 267 |
ELSE |
| 268 |
F_io_net(I,J) = 0.0 |
| 269 |
F_ia_net(I,J) = F_lwd(I,J) + F_swi(I,J) + F_lwu(I,J) + |
| 270 |
& F_sens(I,J) + F_lh(I,J) |
| 271 |
ENDIF !/* conductive fluxes up or down */ |
| 272 |
|
| 273 |
|
| 274 |
#ifdef SEAICE_DEBUG |
| 275 |
print '(A,2i4,3(1x,1P2E15.3))', |
| 276 |
& 'ibi i j T(SURF, surfLoc,atmos)',I,J, |
| 277 |
& TSURF(I,J,bi,bj), tsurfLoc(I,J),atempLoc(I,J) |
| 278 |
|
| 279 |
print '(A,2i4,3(1x,1P2E15.3))', |
| 280 |
& 'ibi i j QSW(Tot, Abs, Pen) ',I,J, |
| 281 |
& SWDOWN(I,J,bi,bj), AbsorbedShortwaveFlux(I,J), |
| 282 |
& IcePenetratingShortwaveFlux(I,J) |
| 283 |
|
| 284 |
print '(A,2i4,3(1x,1P2E15.3))', |
| 285 |
& 'ibi i j IcePenSWFluxFrac, Alb ',I,J, |
| 286 |
^ IcePenetratingShortwaveFluxFraction(I,J), ALB(I,J) |
| 287 |
|
| 288 |
print '(A,2i4,3(1x,1P2E15.3))', |
| 289 |
& 'ibi i j qh(ATM ICE) ',I,J, |
| 290 |
& AQH(I,J,bi,bj),qhice_mm(I,J) |
| 291 |
|
| 292 |
print '(A,2i4,3(1x,1P2E15.3))', |
| 293 |
& 'ibi i j F(lwd,swi,lwu) ',I,J, |
| 294 |
& F_lwd(I,J), F_swi(I,J), F_lwu(I,J) |
| 295 |
|
| 296 |
print '(A,2i4,3(1x,1P2E15.3))', |
| 297 |
& 'ibi i j F(c,lh,sens) ',I,J, |
| 298 |
& F_c(I,J), F_lh(I,J), F_sens(I,J) |
| 299 |
|
| 300 |
print '(A,2i4,3(1x,1P2E15.3))', |
| 301 |
& 'ibi i j F(io_net,ia_net,ia) ',I,J, |
| 302 |
& F_io_net(I,J), F_ia_net(I,J), F_ia(I,J) |
| 303 |
#endif |
| 304 |
|
| 305 |
ENDIF !/* HICE_ACTUAL > 0 */ |
| 306 |
|
| 307 |
ENDDO !/* i */ |
| 308 |
ENDDO !/* j */ |
| 309 |
|
| 310 |
RETURN |
| 311 |
END |
Parent Directory
| 
Revision Log
| 
Revision Graph