/[MITgcm]/MITgcm/pkg/aim_v23/phy_suflux_sice.F
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Contents of /MITgcm/pkg/aim_v23/phy_suflux_sice.F

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Revision 1.4 - (show annotations) (download)
Thu Jun 24 23:43:11 2004 UTC (19 years, 11 months ago) by jmc
Branch: MAIN
CVS Tags: checkpoint54a_pre, checkpoint54a_post, checkpoint54b_post, checkpoint54, checkpoint53g_post, checkpoint53f_post, checkpoint54c_post
Changes since 1.3: +68 -21 lines
- include stability function into surf.Flux derivative relative to Ts
- calculate clear-sky radiation & surface temp. change
- update diagnostics (snap-shot, timeave & diagnostics)

1 C $Header: /u/gcmpack/MITgcm/pkg/aim_v23/phy_suflux_sice.F,v 1.3 2004/05/21 17:43:04 jmc Exp $
2 C $Name: $
3
4 #include "AIM_OPTIONS.h"
5
6 CBOP
7 C !ROUTINE: SUFLUX_SICE
8 C !INTERFACE:
9 SUBROUTINE SUFLUX_SICE(
10 I PSA, FMASK, EMISloc,
11 I Tsurf, dTskin, SSR, SLRD,
12 I T1, T0, Q0, DENVV,
13 O SHF, EVAP, SLRU,
14 O Shf0, dShf, Evp0, dEvp, Slr0, dSlr, sFlx,
15 O TSFC, TSKIN,
16 I bi,bj,myThid)
17
18 C !DESCRIPTION: \bv
19 C *==========================================================*
20 C | S/R SUFLUX_SICE
21 C | o compute surface flux over sea-ice
22 C *==========================================================*
23 C | o contains part of original S/R SUFLUX (Speedy code)
24 C *==========================================================*
25 C \ev
26
27 C !USES:
28 IMPLICIT NONE
29
30 C Resolution parameters
31
32 C-- size for MITgcm & Physics package :
33 #include "AIM_SIZE.h"
34 #include "EEPARAMS.h"
35
36 C-- Physics package
37 #include "AIM_PARAMS.h"
38
39 C Physical constants + functions of sigma and latitude
40 #include "com_physcon.h"
41
42 C Surface flux constants
43 #include "com_sflcon.h"
44
45 C !INPUT/OUTPUT PARAMETERS:
46 C == Routine Arguments ==
47 C-- Input:
48 C PSA :: norm. surface pressure [p/p0] (2-dim)
49 C FMASK :: fractional land-sea mask (2-dim)
50 C EMISloc:: longwave surface emissivity
51 C Tsurf :: surface temperature (2-dim)
52 C dTskin :: temp. correction for daily-cycle heating [K]
53 C SSR :: sfc sw radiation (net flux) (2-dim)
54 C SLRD :: sfc lw radiation (downward flux)(2-dim)
55 C T1 :: near-surface air temperature (from Pot.temp)
56 C T0 :: near-surface air temperature (2-dim)
57 C Q0 :: near-surface sp. humidity [g/kg](2-dim)
58 C DENVV :: surface flux (sens,lat.) coeff. (=Rho*|V|) [kg/m2/s]
59 C-- Output:
60 C SHF :: sensible heat flux (2-dim)
61 C EVAP :: evaporation [g/(m^2 s)] (2-dim)
62 C SLRU :: sfc lw radiation (upward flux) (2-dim)
63 C Shf0 :: sensible heat flux over freezing surf.
64 C dShf :: sensible heat flux derivative relative to surf. temp
65 C Evp0 :: evaporation computed over freezing surface (Ts=0.oC)
66 C dEvp :: evaporation derivative relative to surf. temp
67 C Slr0 :: upward long wave radiation over freezing surf.
68 C dSlr :: upward long wave rad. derivative relative to surf. temp
69 C sFlx :: net heat flux (+=down) except SW, function of surf. temp Ts:
70 C 0: Flux(Ts=0.oC) ; 1: Flux(Ts^n) ; 2: d.Flux/d.Ts(Ts^n)
71 C TSFC :: surface temperature (clim.) (2-dim)
72 C TSKIN :: skin surface temperature (2-dim)
73 C-- Input:
74 C bi,bj :: tile index
75 C myThid :: Thread number for this instance of the routine
76 C--
77 _RL PSA(NGP), FMASK(NGP), EMISloc
78 _RL Tsurf(NGP), dTskin(NGP)
79 _RL SSR(NGP), SLRD(NGP)
80 _RL T1(NGP), T0(NGP), Q0(NGP), DENVV(NGP)
81
82 _RL SHF(NGP), EVAP(NGP), SLRU(NGP)
83 _RL Shf0(NGP), dShf(NGP), Evp0(NGP), dEvp(NGP)
84 _RL Slr0(NGP), dSlr(NGP), sFlx(NGP,0:2)
85 _RL TSFC(NGP), TSKIN(NGP)
86
87 INTEGER bi,bj,myThid
88 CEOP
89
90 #ifdef ALLOW_AIM
91
92 C-- Local variables:
93 C CDENVV :: surf. heat flux (sens.,lat.) coeff including stability effect
94 _RL CDENVV(NGP), RDTH, FSSICE
95 _RL Fstb0, dTstb, dFstb
96 _RL QSAT0(NGP,2)
97 _RL QDUMMY(1), RDUMMY(1), TS2
98 INTEGER J
99
100 C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----|
101
102 C 1.5 Define effective skin temperature to compensate for
103 C non-linearity of heat/moisture fluxes during the daily cycle
104
105 DO J=1,NGP
106 c TSKIN(J) = Tsurf(J) + dTskin(J)
107 c TSFC(J)=273.16 _d 0 + dTskin(J)
108 TSKIN(J) = Tsurf(J)
109 TSFC(J)=273.16 _d 0
110 ENDDO
111
112
113 C-- 2. Computation of fluxes over land and sea
114
115 C 2.1 Stability correction
116
117 RDTH = FSTAB/DTHETA
118
119 DO J=1,NGP
120 FSSICE=1.+MIN(DTHETA,MAX(-DTHETA,TSKIN(J)-T1(J)))*RDTH
121 CDENVV(J)=CHS*DENVV(J)*FSSICE
122 ENDDO
123
124 IF ( dTstab.GT.0. _d 0 ) THEN
125 C- account for stability function derivative relative to Tsurf:
126 C note: to avoid discontinuity in the derivative (because of min,max), compute
127 C the derivative using the discrete form: F(Ts+dTstab)-F(Ts-dTstab)/2.dTstab
128 DO J=1,NGP
129 Fstb0 = 1.+MIN(DTHETA,MAX(-DTHETA,TSFC(J) -T1(J)))*RDTH
130 Shf0(J) = CHL*DENVV(J)*Fstb0
131 dTstb = ( DTHETA+dTstab-ABS(TSKIN(J)-T1(J)) )/dTstab
132 dFstb = RDTH*MIN(1. _d 0, MAX(0. _d 0, dTstb*0.5 _d 0))
133 dShf(J) = CHL*DENVV(J)*dFstb
134 ENDDO
135 ENDIF
136
137 C 2.2 Evaporation
138
139 CALL SHTORH (2, NGP, TSKIN, PSA, 1. _d 0, QDUMMY, dEvp,
140 & QSAT0(1,1), myThid)
141 CALL SHTORH (0, NGP, TSFC, PSA, 1. _d 0, QDUMMY, RDUMMY,
142 & QSAT0(1,2), myThid)
143
144 IF ( dTstab.GT.0. _d 0 ) THEN
145 C- account for stability function derivative relative to Tsurf:
146 DO J=1,NGP
147 EVAP(J) = CDENVV(J)*(QSAT0(J,1)-Q0(J))
148 Evp0(J) = Shf0(J)*(QSAT0(J,2)-Q0(J))
149 dEvp(J) = CDENVV(J)*dEvp(J)
150 & + dShf(J)*(QSAT0(J,1)-Q0(J))
151 ENDDO
152 ELSE
153 DO J=1,NGP
154 EVAP(J) = CDENVV(J)*(QSAT0(J,1)-Q0(J))
155 Evp0(J) = CDENVV(J)*(QSAT0(J,2)-Q0(J))
156 dEvp(J) = CDENVV(J)*dEvp(J)
157 ENDDO
158 ENDIF
159
160 C 2.3 Sensible heat flux
161
162 IF ( dTstab.GT.0. _d 0 ) THEN
163 C- account for stability function derivative relative to Tsurf:
164 DO J=1,NGP
165 SHF(J) = CDENVV(J)*CP*(TSKIN(J)-T0(J))
166 Shf0(J) = Shf0(J)*CP*(TSFC(J) -T0(J))
167 dShf(J) = CDENVV(J)*CP
168 & + dShf(J)*CP*(TSKIN(J)-T0(J))
169 ENDDO
170 ELSE
171 DO J=1,NGP
172 SHF(J) = CDENVV(J)*CP*(TSKIN(J)-T0(J))
173 Shf0(J) = CDENVV(J)*CP*(TSFC(J) -T0(J))
174 dShf(J) = CDENVV(J)*CP
175 dShf(J) = MAX( dShf(J), 0. _d 0 )
176 ENDDO
177 ENDIF
178
179 C 2.4 Emission of lw radiation from the surface
180
181 DO J=1,NGP
182 TS2 = TSFC(J)*TSFC(J)
183 Slr0(J) = SBC*TS2*TS2
184 TS2 = TSKIN(J)*TSKIN(J)
185 SLRU(J) = SBC*TS2*TS2
186 dSlr(J) = 4. _d 0 *SBC*TS2*TSKIN(J)
187 ENDDO
188
189 C-- Compute net surface heat flux and its derivative ./. surf. temp.
190 DO J=1,NGP
191 sFlx(J,0)= ( SLRD(J) - EMISloc*Slr0(J) )
192 & - ( Shf0(J) + ALHC*Evp0(J) )
193 sFlx(J,1)= ( SLRD(J) - EMISloc*SLRU(J) )
194 & - ( SHF(J) + ALHC*EVAP(J) )
195 sFlx(J,2)= -EMISloc*dSlr(J)
196 & - ( dShf(J) + ALHC*dEvp(J) )
197 ENDDO
198 IF ( aim_energPrecip ) THEN
199 C- Evap of snow/ice: substract Latent Heat of freezing from heatFlux
200 DO J=1,NGP
201 sFlx(J,0) = sFlx(J,0) - ALHF*Evp0(J)
202 sFlx(J,1) = sFlx(J,1) - ALHF*EVAP(J)
203 sFlx(J,2) = sFlx(J,2) - ALHF*dEvp(J)
204 ENDDO
205 ENDIF
206
207 C-- 3. Adjustment of skin temperature and fluxes over land
208 C-- based on energy balance (to be implemented)
209 C <= done separately for each surface type (land,ocean,sea-ice)
210
211 C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----|
212 #endif /* ALLOW_AIM */
213
214 RETURN
215 END

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