/[MITgcm]/MITgcm/pkg/seaice/seaice_solve4temp.F
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Revision 1.27 - (hide annotations) (download)
Mon Feb 6 19:19:58 2012 UTC (12 years, 3 months ago) by jmc
Branch: MAIN
Changes since 1.26: +4 -21 lines 
- remove un-used parameters LAD & MAX_TICE ; add new run-time parameters:
  useMaykutSatVapPoly (default=F), postSolvTempIter (default=2) and
  SEAICE_wetAlbTemp (default=-1e-3).
Temporary: change default (useMaykutSatVapPoly=T, postSolvTempIter=0)
  when SEAICE_SOLVE4TEMP_LEGACY is defined or (SEAICE_wetAlbTemp=0.,
  SEAICE_snowThick=0.) if SOLVE4TEMP_LEGACY is undef.
1 jmc 1.27 C $Header: /u/gcmpack/MITgcm/pkg/seaice/seaice_solve4temp.F,v 1.26 2012/02/05 21:06:54 jmc Exp $
2 jmc 1.1 C $Name: $
3    
4     #include "SEAICE_OPTIONS.h"
5 jmc 1.19 #ifdef ALLOW_EXF
6     # include "EXF_OPTIONS.h"
7     #endif
8 jmc 1.1
9     CBOP
10     C !ROUTINE: SEAICE_SOLVE4TEMP
11     C !INTERFACE:
12     SUBROUTINE SEAICE_SOLVE4TEMP(
13     I UG, HICE_ACTUAL, HSNOW_ACTUAL,
14 ifenty 1.16 #ifdef SEAICE_ADD_SUBLIMATION_TO_FWBUDGET
15     I F_lh_max,
16     #endif
17 jmc 1.1 U TSURF,
18 jmc 1.21 O F_ia, IcePenetSW,
19 mlosch 1.10 O FWsublim,
20 jmc 1.1 I bi, bj, myTime, myIter, myThid )
21    
22     C !DESCRIPTION: \bv
23     C *==========================================================*
24     C | SUBROUTINE SOLVE4TEMP
25     C | o Calculate ice growth rate, surface fluxes and
26     C | temperature of ice surface.
27     C | see Hibler, MWR, 108, 1943-1973, 1980
28     C *==========================================================*
29     C \ev
30    
31     C !USES:
32     IMPLICIT NONE
33     C === Global variables ===
34     #include "SIZE.h"
35     #include "GRID.h"
36     #include "EEPARAMS.h"
37 jmc 1.3 #include "PARAMS.h"
38 jmc 1.1 #include "FFIELDS.h"
39 heimbach 1.13 #include "SEAICE_SIZE.h"
40     #include "SEAICE_PARAMS.h"
41 jmc 1.1 #include "SEAICE.h"
42     #ifdef SEAICE_VARIABLE_FREEZING_POINT
43     #include "DYNVARS.h"
44     #endif /* SEAICE_VARIABLE_FREEZING_POINT */
45     #ifdef ALLOW_EXF
46     # include "EXF_FIELDS.h"
47     #endif
48 mlosch 1.8 #ifdef ALLOW_AUTODIFF_TAMC
49     # include "tamc.h"
50     #endif
51 jmc 1.1
52 jmc 1.21 C !INPUT PARAMETERS:
53     C UG :: atmospheric wind speed (m/s)
54 jmc 1.1 C HICE_ACTUAL :: actual ice thickness
55     C HSNOW_ACTUAL :: actual snow thickness
56 jmc 1.21 C TSURF :: surface temperature of ice/snow in Kelvin
57     C bi,bj :: tile indices
58     C myTime :: current time in simulation
59     C myIter :: iteration number in simulation
60     C myThid :: my Thread Id number
61     C !OUTPUT PARAMETERS:
62     C TSURF :: updated surface temperature of ice/snow in Kelvin
63     C F_ia :: upward seaice/snow surface heat flux to atmosphere (W/m^2)
64     C IcePenetSW :: short wave heat flux transmitted through ice (+=upward)
65     C FWsublim :: fresh water (mass) flux due to sublimation (+=up)(kg/m^2/s)
66 jmc 1.24 C---- Notes:
67     C 1) should add IcePenetSW to F_ia to get the net surface heat flux
68     C from the atmosphere (IcePenetSW not currently included in F_ia)
69     C 2) since zero ice/snow heat capacity is assumed, all the absorbed Short
70     C -Wave is used to warm the ice/snow surface (heating profile ignored).
71     C----------
72 jmc 1.21 _RL UG (1:sNx,1:sNy)
73     _RL HICE_ACTUAL (1:sNx,1:sNy)
74     _RL HSNOW_ACTUAL(1:sNx,1:sNy)
75 ifenty 1.16 #ifdef SEAICE_ADD_SUBLIMATION_TO_FWBUDGET
76 jmc 1.21 _RL F_lh_max (1:sNx,1:sNy)
77 ifenty 1.16 #endif
78 jmc 1.21 _RL TSURF (1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy)
79     _RL F_ia (1:sNx,1:sNy)
80     _RL IcePenetSW (1:sNx,1:sNy)
81     _RL FWsublim (1:sNx,1:sNy)
82 jmc 1.1 INTEGER bi, bj
83     _RL myTime
84     INTEGER myIter, myThid
85 jmc 1.19 CEOP
86 jmc 1.1
87 jmc 1.19 #if defined(ALLOW_ATM_TEMP) && defined(ALLOW_DOWNWARD_RADIATION)
88 jmc 1.1 C !LOCAL VARIABLES:
89     C === Local variables ===
90 jmc 1.3 C i, j :: Loop counters
91     C kSrf :: vertical index of surface layer
92 jmc 1.1 INTEGER i, j
93 jmc 1.3 #ifdef SEAICE_VARIABLE_FREEZING_POINT
94     INTEGER kSrf
95     #endif /* SEAICE_VARIABLE_FREEZING_POINT */
96 jmc 1.1 INTEGER ITER
97 jmc 1.21 C TB :: ocean temperature in contact with ice (=seawater freezing point) (K)
98 mlosch 1.5 _RL TB (1:sNx,1:sNy)
99 mlosch 1.18 _RL D1, D1I
100     _RL D3(1:sNx,1:sNy)
101 mlosch 1.5 _RL TMELT, XKI, XKS, HCUT, XIO
102 jmc 1.27 C SurfMeltTemp :: Temp (K) above which wet-albedo values are used
103 mlosch 1.5 _RL SurfMeltTemp
104 jmc 1.21 C effConduct :: effective conductivity of combined ice and snow
105 mlosch 1.5 _RL effConduct(1:sNx,1:sNy)
106 jmc 1.21 C lhSublim :: latent heat of sublimation (SEAICE_lhEvap + SEAICE_lhFusion)
107     _RL lhSublim
108     C t1,t2,t3,t4 :: powers of temperature
109     _RL t1, t2, t3, t4
110 jmc 1.1
111 jmc 1.24 C- Constants to calculate Saturation Vapor Pressure
112 jmc 1.26 C Maykut Polynomial Coeff. for Sat. Vapor Press
113 jmc 1.21 _RL C1, C2, C3, C4, C5, QS1
114 jmc 1.24 C Extended temp-range expon. relation Coeff. for Sat. Vapor Press
115 jmc 1.21 _RL lnTEN
116 jmc 1.1 _RL aa1,aa2,bb1,bb2,Ppascals,cc0,cc1,cc2,cc3t
117     C specific humidity at ice surface variables
118 jmc 1.21 _RL mm_pi,mm_log10pi
119 jmc 1.1
120 jmc 1.22 C F_c :: conductive heat flux through seaice+snow (+=upward)
121 jmc 1.26 C F_lwu :: upward long-wave surface heat flux (+=upward)
122     C F_sens :: sensible surface heat flux (+=upward)
123 jmc 1.21 C F_lh :: latent heat flux (sublimation) (+=upward)
124 jmc 1.24 C qhice :: saturation vapor pressure of snow/ice surface
125     C dqh_dTs :: derivative of qhice w.r.t snow/ice surf. temp
126     C dFia_dTs :: derivative of surf heat flux (F_ia) w.r.t surf. temp
127 jmc 1.26 _RL F_c (1:sNx,1:sNy)
128 jmc 1.21 _RL F_lwu (1:sNx,1:sNy)
129     _RL F_sens (1:sNx,1:sNy)
130     _RL F_lh (1:sNx,1:sNy)
131     _RL qhice (1:sNx,1:sNy)
132 jmc 1.24 _RL dqh_dTs (1:sNx,1:sNy)
133 jmc 1.26 _RL dFia_dTs (1:sNx,1:sNy)
134 jmc 1.21 _RL absorbedSW (1:sNx,1:sNy)
135     _RL penetSWFrac
136 jmc 1.25 _RL delTsurf
137 jmc 1.21
138     C local copies of global variables
139     _RL tsurfLoc (1:sNx,1:sNy)
140 jmc 1.25 _RL tsurfPrev (1:sNx,1:sNy)
141 jmc 1.21 _RL atempLoc (1:sNx,1:sNy)
142     _RL lwdownLoc (1:sNx,1:sNy)
143     _RL ALB (1:sNx,1:sNy)
144     _RL ALB_ICE (1:sNx,1:sNy)
145     _RL ALB_SNOW (1:sNx,1:sNy)
146     C iceOrNot :: this is HICE_ACTUAL.GT.0.
147     LOGICAL iceOrNot(1:sNx,1:sNy)
148     #ifdef SEAICE_DEBUG
149     C F_io_net :: upward conductive heat flux through seaice+snow
150     C F_ia_net :: net heat flux divergence at the sea ice/snow surface:
151     C includes ice conductive fluxes and atmospheric fluxes (W/m^2)
152 jmc 1.25 _RL F_io_net
153     _RL F_ia_net
154 jmc 1.21 #endif /* SEAICE_DEBUG */
155 ifenty 1.14
156 jmc 1.21 C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----|
157 jmc 1.1
158 mlosch 1.8 #ifdef ALLOW_AUTODIFF_TAMC
159     CADJ INIT comlev1_solve4temp = COMMON, sNx*sNy*NMAX_TICE
160     #endif /* ALLOW_AUTODIFF_TAMC */
161    
162 jmc 1.24 C- MAYKUT CONSTANTS FOR SAT. VAP. PRESSURE TEMP. POLYNOMIAL
163 mlosch 1.5 C1= 2.7798202 _d -06
164     C2= -2.6913393 _d -03
165     C3= 0.97920849 _d +00
166     C4= -158.63779 _d +00
167     C5= 9653.1925 _d +00
168 jmc 1.1 QS1=0.622 _d +00/1013.0 _d +00
169 jmc 1.24 C- Extended temp-range expon. relation Coeff. for Sat. Vapor Press
170 jmc 1.21 lnTEN = LOG(10.0 _d 0)
171 jmc 1.1 aa1 = 2663.5 _d 0
172     aa2 = 12.537 _d 0
173     bb1 = 0.622 _d 0
174 mlosch 1.5 bb2 = 1.0 _d 0 - bb1
175 jmc 1.1 Ppascals = 100000. _d 0
176 mlosch 1.5 C cc0 = TEN ** aa2
177 jmc 1.21 cc0 = EXP(aa2*lnTEN)
178 mlosch 1.5 cc1 = cc0*aa1*bb1*Ppascals*lnTEN
179 jmc 1.1 cc2 = cc0*bb2
180    
181 jmc 1.4 #ifdef SEAICE_VARIABLE_FREEZING_POINT
182     kSrf = 1
183     #endif /* SEAICE_VARIABLE_FREEZING_POINT */
184 jmc 1.1
185     C SENSIBLE HEAT CONSTANT
186 mlosch 1.7 D1=SEAICE_dalton*SEAICE_cpAir*SEAICE_rhoAir
187 jmc 1.1
188     C ICE LATENT HEAT CONSTANT
189 ifenty 1.14 lhSublim = SEAICE_lhEvap + SEAICE_lhFusion
190     D1I=SEAICE_dalton*lhSublim*SEAICE_rhoAir
191 jmc 1.1
192     C MELTING TEMPERATURE OF ICE
193 mlosch 1.5 TMELT = celsius2K
194 jmc 1.1
195     C ICE CONDUCTIVITY
196     XKI=SEAICE_iceConduct
197    
198     C SNOW CONDUCTIVITY
199     XKS=SEAICE_snowConduct
200    
201     C CUTOFF SNOW THICKNESS
202 jmc 1.21 C Snow-Thickness above HCUT: SW optically thick snow (=> snow-albedo).
203     C Snow-Thickness below HCUT: linear transition to ice-albedo
204 jmc 1.24 HCUT = SEAICE_snowThick
205    
206 jmc 1.26 C Wet/dry albebo temperature threshold
207     SEAICE_wetAlbTemp = - 1. _d -3
208    
209 jmc 1.24 C PENETRATION SHORTWAVE RADIATION FACTOR
210     XIO=SEAICE_shortwave
211    
212 jmc 1.27 C Temperature Threshold for wet-albedo:
213     SurfMeltTemp = TMELT + SEAICE_wetAlbTemp
214 jmc 1.24 C old SOLVE4TEMP_LEGACY setting, consistent with former celsius2K value:
215     c TMELT = 273.16 _d +00
216     c SurfMeltTemp = 273.159 _d +00
217 jmc 1.1
218 jmc 1.3 C Initialize variables
219 jmc 1.1 DO J=1,sNy
220 mlosch 1.5 DO I=1,sNx
221     C HICE_ACTUAL is modified in this routine, but at the same time
222     C used to decided where there is ice, therefore we save this information
223     C here in a separate array
224 jmc 1.21 iceOrNot (I,J) = HICE_ACTUAL(I,J) .GT. 0. _d 0
225     IcePenetSW(I,J) = 0. _d 0
226     absorbedSW(I,J) = 0. _d 0
227 mlosch 1.5 qhice (I,J) = 0. _d 0
228 jmc 1.24 dqh_dTs (I,J) = 0. _d 0
229 mlosch 1.5 F_ia (I,J) = 0. _d 0
230 mlosch 1.10 F_lh (I,J) = 0. _d 0
231 mlosch 1.5 F_lwu (I,J) = 0. _d 0
232     F_sens (I,J) = 0. _d 0
233 jmc 1.26 C Make a local copy of LW, surface & atmospheric temperatures
234 mlosch 1.5 tsurfLoc (I,J) = TSURF(I,J,bi,bj)
235 jmc 1.26 c tsurfLoc (I,J) = MIN( celsius2K+MAX_TICE, TSURF(I,J,bi,bj) )
236     lwdownLoc(I,J) = MAX( MIN_LWDOWN, LWDOWN(I,J,bi,bj) )
237 jmc 1.24 atempLoc (I,J) = MAX( celsius2K+MIN_ATEMP, ATEMP(I,J,bi,bj) )
238 jmc 1.1
239 mlosch 1.5 C FREEZING TEMPERATURE OF SEAWATER
240     #ifdef SEAICE_VARIABLE_FREEZING_POINT
241     C Use a variable seawater freezing point
242     TB(I,J) = -0.0575 _d 0*salt(I,J,kSrf,bi,bj) + 0.0901 _d 0
243     & + celsius2K
244     #else
245     C Use a constant freezing temperature (SEAICE_VARIABLE_FREEZING_POINT undef)
246 jmc 1.23 C old SOLVE4TEMP_LEGACY setting (not consistent with seaice_growth value)
247     c TB(I,J) = 271.2 _d 0
248 mlosch 1.5 TB(I,J) = celsius2K + SEAICE_freeze
249     #endif /* SEAICE_VARIABLE_FREEZING_POINT */
250 jmc 1.26
251     C Now determine fixed (relative to tsurf) forcing term in heat budget
252    
253 mlosch 1.18 IF(HSNOW_ACTUAL(I,J).GT.0.0) THEN
254 jmc 1.21 C Stefan-Boltzmann constant times emissivity
255 mlosch 1.18 D3(I,J)=SEAICE_snow_emiss*SEAICE_boltzmann
256     #ifdef EXF_LWDOWN_WITH_EMISSIVITY
257     C This is now [(1-emiss)*lwdown - lwdown]
258 jmc 1.26 lwdownLoc(I,J) = SEAICE_snow_emiss*lwdownLoc(I,J)
259 mlosch 1.18 #else /* use the old hard wired inconsistent value */
260 jmc 1.26 lwdownLoc(I,J) = 0.97 _d 0*lwdownLoc(I,J)
261 mlosch 1.18 #endif /* EXF_LWDOWN_WITH_EMISSIVITY */
262     ELSE
263 jmc 1.21 C Stefan-Boltzmann constant times emissivity
264 mlosch 1.18 D3(I,J)=SEAICE_ice_emiss*SEAICE_boltzmann
265     #ifdef EXF_LWDOWN_WITH_EMISSIVITY
266     C This is now [(1-emiss)*lwdown - lwdown]
267 jmc 1.26 lwdownLoc(I,J) = SEAICE_ice_emiss*lwdownLoc(I,J)
268 mlosch 1.18 #else /* use the old hard wired inconsistent value */
269 jmc 1.26 lwdownLoc(I,J) = 0.97 _d 0*lwdownLoc(I,J)
270 mlosch 1.18 #endif /* EXF_LWDOWN_WITH_EMISSIVITY */
271     ENDIF
272 mlosch 1.5 ENDDO
273 jmc 1.1 ENDDO
274    
275     DO J=1,sNy
276 mlosch 1.5 DO I=1,sNx
277 jmc 1.1
278     C DECIDE ON ALBEDO
279 mlosch 1.5 IF ( iceOrNot(I,J) ) THEN
280 jmc 1.6
281 mlosch 1.5 IF ( YC(I,J,bi,bj) .LT. 0.0 _d 0 ) THEN
282     IF (tsurfLoc(I,J) .GE. SurfMeltTemp) THEN
283     ALB_ICE (I,J) = SEAICE_wetIceAlb_south
284     ALB_SNOW(I,J) = SEAICE_wetSnowAlb_south
285     ELSE ! no surface melting
286     ALB_ICE (I,J) = SEAICE_dryIceAlb_south
287     ALB_SNOW(I,J) = SEAICE_drySnowAlb_south
288     ENDIF
289     ELSE !/ Northern Hemisphere
290     IF (tsurfLoc(I,J) .GE. SurfMeltTemp) THEN
291     ALB_ICE (I,J) = SEAICE_wetIceAlb
292     ALB_SNOW(I,J) = SEAICE_wetSnowAlb
293     ELSE ! no surface melting
294     ALB_ICE (I,J) = SEAICE_dryIceAlb
295     ALB_SNOW(I,J) = SEAICE_drySnowAlb
296     ENDIF
297     ENDIF !/ Albedo for snow and ice
298    
299 jmc 1.21 C If actual snow thickness exceeds the cutoff thickness, use snow albedo
300 mlosch 1.5 IF (HSNOW_ACTUAL(I,J) .GT. HCUT) THEN
301     ALB(I,J) = ALB_SNOW(I,J)
302 jmc 1.21 ELSEIF ( HCUT.LE.ZERO ) THEN
303     ALB(I,J) = ALB_ICE(I,J)
304 mlosch 1.5 ELSE
305 jmc 1.21 C otherwise, use linear transition between ice and snow albedo
306     ALB(I,J) = MIN( ALB_ICE(I,J) + HSNOW_ACTUAL(I,J)/HCUT
307     & *(ALB_SNOW(I,J) -ALB_ICE(I,J))
308     & , ALB_SNOW(I,J) )
309 mlosch 1.5 ENDIF
310    
311 jmc 1.21 C Determine the fraction of shortwave radiative flux remaining
312     C at ocean interface after scattering through the snow and ice.
313     C If snow is present, no radiation penetrates through snow+ice
314 mlosch 1.5 IF (HSNOW_ACTUAL(I,J) .GT. 0.0 _d 0) THEN
315 jmc 1.21 penetSWFrac = 0.0 _d 0
316 mlosch 1.5 ELSE
317 jmc 1.21 penetSWFrac = XIO*EXP(-1.5 _d 0 * HICE_ACTUAL(I,J))
318 mlosch 1.5 ENDIF
319 jmc 1.21 C The shortwave radiative flux leaving ocean beneath ice (+=up).
320     IcePenetSW(I,J) = -(1.0 _d 0 - ALB(I,J))
321     & *penetSWFrac * SWDOWN(I,J,bi,bj)
322     C The shortwave radiative flux convergence in the seaice.
323     absorbedSW(I,J) = (1.0 _d 0 - ALB(I,J))
324     & *(1.0 _d 0 - penetSWFrac)* SWDOWN(I,J,bi,bj)
325 jmc 1.1
326 jmc 1.24 C The effective conductivity of the two-layer snow/ice system.
327 jmc 1.26 C Set a minimum sea ice thickness of 5 cm to bound
328 jmc 1.21 C the magnitude of conductive heat fluxes.
329     Cif * now taken care of by SEAICE_hice_reg in seaice_growth
330     c hice_tmp = max(HICE_ACTUAL(I,J),5. _d -2)
331 mlosch 1.5 effConduct(I,J) = XKI * XKS /
332 jmc 1.21 & (XKS * HICE_ACTUAL(I,J) + XKI * HSNOW_ACTUAL(I,J))
333 jmc 1.1
334     #ifdef SEAICE_DEBUG
335 jmc 1.21 IF ( (I .EQ. SEAICE_debugPointI) .AND.
336 ifenty 1.16 & (J .EQ. SEAICE_debugPointJ) ) THEN
337 mlosch 1.5 print '(A,i6)','-----------------------------------'
338     print '(A,i6)','ibi merged initialization ', myIter
339     print '(A,i6,4(1x,D24.15))',
340     & 'ibi iter, TSL, TS ',myIter,
341     & tsurfLoc(I,J), TSURF(I,J,bi,bj)
342     print '(A,i6,4(1x,D24.15))',
343     & 'ibi iter, TMELT ',myIter,TMELT
344     print '(A,i6,4(1x,D24.15))',
345     & 'ibi iter, HIA, EFKCON ',myIter,
346     & HICE_ACTUAL(I,J), effConduct(I,J)
347     print '(A,i6,4(1x,D24.15))',
348     & 'ibi iter, HSNOW ',myIter,
349     & HSNOW_ACTUAL(I,J), ALB(I,J)
350     print '(A,i6)','-----------------------------------'
351     print '(A,i6)','ibi energy balance iterat ', myIter
352     ENDIF
353 jmc 1.2 #endif /* SEAICE_DEBUG */
354 jmc 1.6
355 mlosch 1.5 ENDIF !/* iceOrNot */
356     ENDDO !/* i */
357     ENDDO !/* j */
358 jmc 1.21
359     C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----|
360 mlosch 1.5 DO ITER=1,IMAX_TICE
361     DO J=1,sNy
362     DO I=1,sNx
363 mlosch 1.8 #ifdef ALLOW_AUTODIFF_TAMC
364     iicekey = I + sNx*(J-1) + (ITER-1)*sNx*sNy
365 jmc 1.26 CADJ STORE tsurfLoc(i,j) = comlev1_solve4temp,
366 mlosch 1.8 CADJ & key = iicekey, byte = isbyte
367     #endif /* ALLOW_AUTODIFF_TAMC */
368    
369 jmc 1.25 C- save tsurf from previous iter
370     tsurfPrev(I,J) = tsurfLoc(I,J)
371 mlosch 1.5 IF ( iceOrNot(I,J) ) THEN
372 jmc 1.1
373 mlosch 1.5 t1 = tsurfLoc(I,J)
374     t2 = t1*t1
375     t3 = t2*t1
376     t4 = t2*t2
377 jmc 1.1
378 jmc 1.24 C-- Calculate the specific humidity in the BL above the snow/ice
379 jmc 1.25 IF ( useMaykutSatVapPoly ) THEN
380 jmc 1.24 C- Use the Maykut polynomial
381 jmc 1.25 qhice(I,J)=QS1*(C1*t4+C2*t3 +C3*t2+C4*t1+C5)
382     dqh_dTs(I,J) = 0. _d 0
383     ELSE
384 jmc 1.24 C- Use exponential relation approx., more accurate at low temperatures
385 mlosch 1.5 C log 10 of the sat vap pressure
386 jmc 1.25 mm_log10pi = -aa1 / t1 + aa2
387 mlosch 1.5 C The saturation vapor pressure (SVP) in the surface
388     C boundary layer (BL) above the snow/ice.
389 jmc 1.25 c mm_pi = TEN **(mm_log10pi)
390 jmc 1.6 C The following form does the same, but is faster
391 jmc 1.25 mm_pi = EXP(mm_log10pi*lnTEN)
392     qhice(I,J) = bb1*mm_pi/( Ppascals -(1.0 _d 0 - bb1)*mm_pi )
393 jmc 1.21 C A constant for SVP derivative w.r.t TICE
394 jmc 1.25 c cc3t = TEN **(aa1 / t1)
395 jmc 1.21 C The following form does the same, but is faster
396 jmc 1.25 cc3t = EXP(aa1 / t1 * lnTEN)
397 jmc 1.21 C d(qh)/d(TICE)
398 jmc 1.25 dqh_dTs(I,J) = cc1*cc3t/((cc2-cc3t*Ppascals)**2 *t2)
399     ENDIF
400 jmc 1.1
401 mlosch 1.10 C Calculate the flux terms based on the updated tsurfLoc
402 jmc 1.22 F_c(I,J) = effConduct(I,J)*(TB(I,J)-tsurfLoc(I,J))
403 mlosch 1.10 F_lh(I,J) = D1I*UG(I,J)*(qhice(I,J)-AQH(I,J,bi,bj))
404 ifenty 1.16 #ifdef SEAICE_ADD_SUBLIMATION_TO_FWBUDGET
405 jmc 1.21 C if the latent heat flux implied by tsurfLoc exceeds
406     C F_lh_max, cap F_lh and decouple the flux magnitude from TICE
407     IF (F_lh(I,J) .GT. F_lh_max(I,J)) THEN
408 ifenty 1.16 F_lh(I,J) = F_lh_max(I,J)
409 jmc 1.24 dqh_dTs(I,J) = ZERO
410 jmc 1.21 ENDIF
411     #endif /* SEAICE_ADD_SUBLIMATION_TO_FWBUDGET */
412 ifenty 1.16
413 jmc 1.21 F_lwu(I,J) = t4 * D3(I,J)
414 mlosch 1.5 F_sens(I,J)= D1 * UG(I,J) * (t1 - atempLoc(I,J))
415 jmc 1.21 F_ia(I,J) = -lwdownLoc(I,J) -absorbedSW(I,J) + F_lwu(I,J)
416 jmc 1.24 & + F_sens(I,J) + F_lh(I,J)
417 jmc 1.26 C d(F_ia)/d(Tsurf)
418     dFia_dTs(I,J) = 4.0 _d 0*D3(I,J)*t3 + D1*UG(I,J)
419     & + D1I*UG(I,J)*dqh_dTs(I,J)
420 jmc 1.1
421     #ifdef SEAICE_DEBUG
422 jmc 1.21 IF ( (I .EQ. SEAICE_debugPointI) .AND.
423 ifenty 1.16 & (J .EQ. SEAICE_debugPointJ) ) THEN
424 mlosch 1.5 print '(A,i6,4(1x,D24.15))',
425     & 'ice-iter qhICE, ', ITER,qhIce(I,J)
426     print '(A,i6,4(1x,D24.15))',
427 jmc 1.24 & 'ice-iter dFiDTs1 F_ia ', ITER,
428     & dFia_dTs(I,J)+effConduct(I,J), F_ia(I,J)-F_c(I,J)
429 mlosch 1.5 ENDIF
430 jmc 1.2 #endif /* SEAICE_DEBUG */
431 jmc 1.1
432 jmc 1.26 C- Update tsurf as solution of : Fc = Fia + d/dT(Fia - Fc) *delta.tsurf
433 jmc 1.24 tsurfLoc(I,J) = tsurfLoc(I,J)
434     & + ( F_c(I,J)-F_ia(I,J) ) / ( effConduct(I,J)+dFia_dTs(I,J) )
435 jmc 1.1
436 jmc 1.26 IF ( useMaykutSatVapPoly ) THEN
437     tsurfLoc(I,J) = MAX( celsius2K+MIN_TICE, tsurfLoc(I,J) )
438     ENDIF
439 jmc 1.21 C If the search leads to tsurfLoc < 50 Kelvin, restart the search
440     C at tsurfLoc = TMELT. Note that one solution to the energy balance problem
441     C is an extremely low temperature - a temperature far below realistic values.
442 jmc 1.26 c IF (tsurfLoc(I,J) .LT. 50.0 _d 0 ) tsurfLoc(I,J) = TMELT
443     C Comments & code above not relevant anymore (from older version, when
444     C trying Maykut-Polynomial & dqh_dTs > 0 ?): commented out
445 jmc 1.21 tsurfLoc(I,J) = MIN( tsurfLoc(I,J), TMELT )
446 jmc 1.1
447     #ifdef SEAICE_DEBUG
448 jmc 1.21 IF ( (I .EQ. SEAICE_debugPointI) .AND.
449 ifenty 1.16 & (J .EQ. SEAICE_debugPointJ) ) THEN
450 mlosch 1.5 print '(A,i6,4(1x,D24.15))',
451     & 'ice-iter tsurfLc,|dif|', ITER,
452     & tsurfLoc(I,J),
453 jmc 1.21 & LOG10(ABS(tsurfLoc(I,J) - t1))
454 mlosch 1.5 ENDIF
455 jmc 1.2 #endif /* SEAICE_DEBUG */
456 jmc 1.1
457 mlosch 1.5 ENDIF !/* iceOrNot */
458     ENDDO !/* i */
459     ENDDO !/* j */
460     ENDDO !/* Iterations */
461 jmc 1.21 C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----|
462    
463 mlosch 1.5 DO J=1,sNy
464     DO I=1,sNx
465     IF ( iceOrNot(I,J) ) THEN
466 jmc 1.1
467 jmc 1.21 C Save updated tsurf and finalize the flux terms
468     TSURF(I,J,bi,bj) = tsurfLoc(I,J)
469    
470 jmc 1.25 #ifdef SEAICE_MODIFY_GROWTH_ADJ
471     Cgf no additional dependency through solver, snow, etc.
472     IF ( SEAICEadjMODE.GE.2 ) THEN
473     CALL ZERO_ADJ_1D( 1, TSURF(I,J,bi,bj), myThid)
474 jmc 1.26 absorbedSW(I,J) = 0.3 _d 0 *SWDOWN(I,J,bi,bj)
475     IcePenetSW(I,J)= 0. _d 0
476     ENDIF
477     IF ( postSolvTempIter.EQ.2 .OR. SEAICEadjMODE.GE.2 ) THEN
478 jmc 1.25 t1 = TSURF(I,J,bi,bj)
479     #else /* SEAICE_MODIFY_GROWTH_ADJ */
480    
481     IF ( postSolvTempIter.EQ.2 ) THEN
482 mlosch 1.5 C Recalculate the fluxes based on the (possibly) adjusted TSURF
483 jmc 1.25 t1 = tsurfLoc(I,J)
484 jmc 1.26 #endif /* SEAICE_MODIFY_GROWTH_ADJ */
485 jmc 1.25 t2 = t1*t1
486     t3 = t2*t1
487     t4 = t2*t2
488 jmc 1.1
489 jmc 1.25 IF ( useMaykutSatVapPoly ) THEN
490     qhice(I,J)=QS1*(C1*t4+C2*t3 +C3*t2+C4*t1+C5)
491     ELSE
492 mlosch 1.5 C log 10 of the sat vap pressure
493 jmc 1.25 mm_log10pi = -aa1 / t1 + aa2
494 mlosch 1.5 C saturation vapor pressure
495 jmc 1.25 c mm_pi = TEN **(mm_log10pi)
496 jmc 1.6 C The following form does the same, but is faster
497 jmc 1.25 mm_pi = EXP(mm_log10pi*lnTEN)
498 jmc 1.21 C over ice specific humidity
499 jmc 1.25 qhice(I,J) = bb1*mm_pi/( Ppascals -(1.0 _d 0 - bb1)*mm_pi )
500     ENDIF
501 jmc 1.26 F_c(I,J) = effConduct(I,J) * (TB(I,J) - t1)
502 jmc 1.25 F_lh(I,J) = D1I * UG(I,J)*(qhice(I,J)-AQH(I,J,bi,bj))
503 ifenty 1.16 #ifdef SEAICE_ADD_SUBLIMATION_TO_FWBUDGET
504 jmc 1.25 IF (F_lh(I,J) .GT. F_lh_max(I,J)) THEN
505 ifenty 1.16 F_lh(I,J) = F_lh_max(I,J)
506 jmc 1.25 ENDIF
507 jmc 1.21 #endif /* SEAICE_ADD_SUBLIMATION_TO_FWBUDGET */
508 jmc 1.25 F_lwu(I,J) = t4 * D3(I,J)
509     F_sens(I,J) = D1 * UG(I,J) * (t1 - atempLoc(I,J))
510 jmc 1.21 C The flux between the ice/snow surface and the atmosphere.
511 jmc 1.25 F_ia(I,J) = -lwdownLoc(I,J) -absorbedSW(I,J) + F_lwu(I,J)
512     & + F_sens(I,J) + F_lh(I,J)
513 jmc 1.1
514 jmc 1.25 ELSEIF ( postSolvTempIter.EQ.1 ) THEN
515     C Update fluxes (consistent with the linearized formulation)
516     delTsurf = tsurfLoc(I,J)-tsurfPrev(I,J)
517     F_c(I,J) = effConduct(I,J)*(TB(I,J)-tsurfLoc(I,J))
518     F_ia(I,J) = F_ia(I,J) + dFia_dTs(I,J)*delTsurf
519     F_lh(I,J) = F_lh(I,J)
520     & + D1I*UG(I,J)*dqh_dTs(I,J)*delTsurf
521 jmc 1.26
522     c ELSEIF ( postSolvTempIter.EQ.0 ) THEN
523 jmc 1.25 C Take fluxes from last iteration
524 jmc 1.26
525 jmc 1.25 ELSEIF ( postSolvTempIter.NE.0 ) THEN
526 jmc 1.26 STOP 'SEAICE_SOLVE4TEMP: invalid postSolvTempIter'
527 jmc 1.21 ENDIF
528    
529     C Fresh water flux (kg/m^2/s) from latent heat of sublimation.
530     C F_lh is positive upward (sea ice looses heat) and FWsublim
531     C is also positive upward (atmosphere gains freshwater)
532     FWsublim(I,J) = F_lh(I,J)/lhSublim
533 gforget 1.9
534 jmc 1.21 #ifdef SEAICE_DEBUG
535 jmc 1.26 C Calculate the net ice-ocean and ice-atmosphere fluxes
536 jmc 1.22 IF (F_c(I,J) .GT. 0.0 _d 0) THEN
537 jmc 1.25 F_io_net = F_c(I,J)
538     F_ia_net = 0.0 _d 0
539 mlosch 1.5 ELSE
540 jmc 1.25 F_io_net = 0.0 _d 0
541     F_ia_net = F_ia(I,J)
542 mlosch 1.5 ENDIF !/* conductive fluxes up or down */
543 jmc 1.1
544 jmc 1.21 IF ( (I .EQ. SEAICE_debugPointI) .AND.
545 ifenty 1.16 & (J .EQ. SEAICE_debugPointJ) ) THEN
546 mlosch 1.5 print '(A)','----------------------------------------'
547     print '(A,i6)','ibi complete ', myIter
548     print '(A,4(1x,D24.15))',
549     & 'ibi T(SURF, surfLoc,atmos) ',
550     & TSURF(I,J,bi,bj), tsurfLoc(I,J),atempLoc(I,J)
551     print '(A,4(1x,D24.15))',
552     & 'ibi LWL ', lwdownLoc(I,J)
553     print '(A,4(1x,D24.15))',
554     & 'ibi QSW(Total, Penetrating)',
555 jmc 1.21 & SWDOWN(I,J,bi,bj), IcePenetSW(I,J)
556 mlosch 1.5 print '(A,4(1x,D24.15))',
557     & 'ibi qh(ATM ICE) ',
558     & AQH(I,J,bi,bj),qhice(I,J)
559 ifenty 1.16 print '(A,4(1x,D24.15))',
560     & 'ibi F(lwd,swi,lwu) ',
561 jmc 1.21 & -lwdownLoc(I,J), -absorbedSW(I,J), F_lwu(I,J)
562 ifenty 1.16 print '(A,4(1x,D24.15))',
563     & 'ibi F(c,lh,sens) ',
564     & F_c(I,J), F_lh(I,J), F_sens(I,J)
565     #ifdef SEAICE_ADD_SUBLIMATION_TO_FWBUDGET
566     IF (F_lh_max(I,J) .GT. ZERO) THEN
567     print '(A,4(1x,D24.15))',
568     & 'ibi F_lh_max, F_lh/lhmax) ',
569     & F_lh_max(I,J), F_lh(I,J)/ F_lh_max(I,J)
570 jmc 1.19 ELSE
571 ifenty 1.16 print '(A,4(1x,D24.15))',
572     & 'ibi F_lh_max = ZERO! '
573     ENDIF
574     print '(A,4(1x,D24.15))',
575     & 'ibi FWsub, FWsubm*dT/rhoI ',
576     & FWsublim(I,J),
577     & FWsublim(I,J)*SEAICE_deltaTtherm/SEAICE_rhoICE
578 jmc 1.21 #endif /* SEAICE_ADD_SUBLIMATION_TO_FWBUDGET */
579 mlosch 1.5 print '(A,4(1x,D24.15))',
580     & 'ibi F_ia, F_ia_net, F_c ',
581 jmc 1.25 & F_ia(I,J), F_ia_net, F_c(I,J)
582 mlosch 1.5 print '(A)','----------------------------------------'
583     ENDIF
584 jmc 1.2 #endif /* SEAICE_DEBUG */
585 jmc 1.6
586 mlosch 1.5 ENDIF !/* iceOrNot */
587     ENDDO !/* i */
588 jmc 1.1 ENDDO !/* j */
589    
590 jmc 1.19 #endif /* ALLOW_ATM_TEMP && ALLOW_DOWNWARD_RADIATION */
591     RETURN
592 jmc 1.1 END
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