/[MITgcm]/MITgcm/pkg/ggl90/ggl90_calc.F
ViewVC logotype

Annotation of /MITgcm/pkg/ggl90/ggl90_calc.F

Parent Directory Parent Directory | Revision Log Revision Log | View Revision Graph Revision Graph


Revision 1.1 - (hide annotations) (download)
Thu Sep 16 11:27:18 2004 UTC (19 years, 8 months ago) by mlosch
Branch: MAIN
CVS Tags: checkpoint55c_post, checkpoint55b_post, checkpoint55, checkpoint54f_post, checkpoint55a_post
o initial check-in of TKE-model of Gaspar et al. 1990

1 mlosch 1.1 C $Header: $
2     C $Name: $
3    
4     #include "GGL90_OPTIONS.h"
5    
6     CBOP
7     C !ROUTINE: GGL90_CALC
8    
9     C !INTERFACE: ======================================================
10     subroutine GGL90_CALC(
11     I bi, bj, myTime, myThid )
12    
13     C !DESCRIPTION: \bv
14     C /==========================================================\
15     C | SUBROUTINE GGL90_CALC |
16     C | o Compute all GGL90 fields defined in GGL90.h |
17     C |==========================================================|
18     C | Equation numbers refer to |
19     C | Gaspar et al. (1990), JGR 95 (C9), pp 16,179 |
20     C | Some parts of the implementation follow Blanke and |
21     C | Delecuse (1993), JPO, and OPA code, in particular the |
22     C | computation of the |
23     C | mixing length = max(min(lk,depth),lkmin) |
24     C \==========================================================/
25     IMPLICIT NONE
26     C
27     C--------------------------------------------------------------------
28    
29     C global parameters updated by ggl90_calc
30     C GGL90TKE - sub-grid turbulent kinetic energy (m^2/s^2)
31     C GGL90viscAz - GGL90 eddy viscosity coefficient (m^2/s)
32     C GGL90diffKzT - GGL90 diffusion coefficient for temperature (m^2/s)
33     C
34     C \ev
35    
36     C !USES: ============================================================
37     #include "SIZE.h"
38     #include "EEPARAMS.h"
39     #include "PARAMS.h"
40     #include "DYNVARS.h"
41     #include "GGL90.h"
42     #include "FFIELDS.h"
43     #include "GRID.h"
44    
45     C !INPUT PARAMETERS: ===================================================
46     c Routine arguments
47     c bi, bj - array indices on which to apply calculations
48     c myTime - Current time in simulation
49    
50     INTEGER bi, bj
51     INTEGER myThid
52     _RL myTime
53    
54     #ifdef ALLOW_GGL90
55    
56     C !LOCAL VARIABLES: ====================================================
57     c Local constants
58     C iMin, iMax, jMin, jMax, I, J - array computation indices
59     C K, Kp1, km1, kSurf, kBottom - vertical loop indices
60     C ab15, ab05 - weights for implicit timestepping
61     C uStarSquare - square of friction velocity
62     C verticalShear - (squared) vertical shear of horizontal velocity
63     C Nsquare - squared buoyancy freqency
64     C RiNumber - local Richardson number
65     C KappaM - (local) viscosity parameter (eq.10)
66     C KappaH - (local) diffusivity parameter for temperature (eq.11)
67     C KappaE - (local) diffusivity parameter for TKE (eq.15)
68     C buoyFreq - buoyancy freqency
69     C TKEdissipation - dissipation of TKE
70     C GGL90mixingLength- mixing length of scheme following Banke+Delecuse
71     C totalDepth - thickness of water column (inverse of recip_Rcol)
72     C TKEPrandtlNumber - here, an empirical function of the Richardson number
73     C rhoK, rhoKm1 - density at layer K and Km1 (relative to K)
74     C gTKE - right hand side of implicit equation
75     INTEGER iMin ,iMax ,jMin ,jMax
76     INTEGER I, J, K, Kp1, Km1, kSurf, kBottom
77     _RL ab15, ab05
78     _RL uStarSquare
79     _RL verticalShear
80     _RL KappaM, KappaH
81     _RL Nsquare
82     _RL deltaTggl90
83     _RL SQRTTKE
84     _RL RiNumber
85     _RL TKEdissipation
86     _RL tempU, tempV, prTemp
87     _RL TKEPrandtlNumber (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
88     _RL GGL90mixingLength(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
89     _RL KappaE (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
90     _RL rhoK (1-OLx:sNx+OLx,1-OLy:sNy+OLy)
91     _RL rhoKm1 (1-OLx:sNx+OLx,1-OLy:sNy+OLy)
92     _RL totalDepth (1-OLx:sNx+OLx,1-OLy:sNy+OLy)
93     _RL gTKE (1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
94     C tri-diagonal matrix
95     _RL a(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
96     _RL b(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
97     _RL c(1-OLx:sNx+OLx,1-OLy:sNy+OLy,Nr)
98     CEOP
99     iMin = 2-OLx
100     iMax = sNx+OLx-1
101     jMin = 2-OLy
102     jMax = sNy+OLy-1
103    
104     C set separate time step (should be deltaTtracer)
105     deltaTggl90 = deltaTtracer
106     C
107     kSurf = 1
108     C implicit timestepping weights for dissipation
109     ab15 = 1.5 _d 0
110     ab05 = -0.5 _d 0
111     ab15 = 1. _d 0
112     ab05 = 0. _d 0
113    
114     C Initialize local fields
115     DO K = 1, Nr
116     DO J=1-Oly,sNy+Oly
117     DO I=1-Olx,sNx+Olx
118     gTKE(I,J,K) = 0. _d 0
119     KappaE(I,J,K) = 0. _d 0
120     TKEPrandtlNumber(I,J,K) = 0. _d 0
121     GGL90mixingLength(I,J,K) = 0. _d 0
122     ENDDO
123     ENDDO
124     ENDDO
125     DO J=1-Oly,sNy+Oly
126     DO I=1-Olx,sNx+Olx
127     rhoK (I,J) = 0. _d 0
128     rhoKm1 (I,J) = 0. _d 0
129     totalDepth(I,J) = 0. _d 0
130     IF ( recip_Rcol(I,J,bi,bj) .NE. 0. )
131     & totalDepth(I,J) = 1./recip_Rcol(I,J,bi,bj)
132     ENDDO
133     ENDDO
134    
135     C start k-loop
136     DO K = 2, Nr
137     Km1 = K-1
138     Kp1 = MIN(Nr,K+1)
139     CALL FIND_RHO(
140     I bi, bj, iMin, iMax, jMin, jMax, Km1, K,
141     I theta, salt,
142     O rhoKm1,
143     I myThid )
144     CALL FIND_RHO(
145     I bi, bj, iMin, iMax, jMin, jMax, K, K,
146     I theta, salt,
147     O rhoK,
148     I myThid )
149     DO J=jMin,jMax
150     DO I=iMin,iMax
151     SQRTTKE=SQRT( GGL90TKE(I,J,K,bi,bj) )
152     C
153     C buoyancy frequency
154     C
155     Nsquare = - gravity*recip_rhoConst*recip_drC(K)
156     & * ( rhoKm1(I,J) - rhoK(I,J) )*maskC(I,J,K,bi,bj)
157     C vertical shear term (dU/dz)^2+(dV/dz)^2
158     tempu= .5*( uVel(I,J,Km1,bi,bj)+uVel(I+1,J,Km1,bi,bj)
159     & - (uVel(I,J,K ,bi,bj)+uVel(I+1,J,K ,bi,bj)) )
160     & *recip_drC(K)
161     tempv= .5*( vVel(I,J,Km1,bi,bj)+vVel(I,J+1,Km1,bi,bj)
162     & - (vVel(I,J,K ,bi,bj)+vVel(I,J+1,K ,bi,bj)) )
163     & *recip_drC(K)
164     verticalShear = tempU*tempU + tempV*tempV
165     RiNumber = MAX(Nsquare,0. _d 0)/(verticalShear+GGL90eps)
166     C compute Prandtl number (always greater than 0)
167     prTemp = 1. _d 0
168     IF ( RiNumber .GE. 0.2 ) prTemp = 5.0 * RiNumber
169     TKEPrandtlNumber(I,J,K) = MIN(10.,prTemp)
170     C mixing length
171     GGL90mixingLength(I,J,K) =
172     & SQRTTKE/SQRT( MAX(Nsquare,GGL90eps) )
173     C impose upper bound for mixing length (total depth)
174     GGL90mixingLength(I,J,K) = MIN(GGL90mixingLength(I,J,K),
175     & totalDepth(I,J))
176     C impose minimum mixing length (to avoid division by zero)
177     GGL90mixingLength(I,J,K) = MAX(GGL90mixingLength(I,J,K),
178     & GGL90mixingLengthMin)
179     C viscosity of last timestep
180     KappaM = GGL90ck*GGL90mixingLength(I,J,K)*SQRTTKE
181     KappaE(I,J,K) = KappaM*GGL90alpha
182     C dissipation term
183     TKEdissipation = ab05*GGL90ceps
184     & *SQRTTKE/GGL90mixingLength(I,J,K)
185     & *GGL90TKE(I,J,K,bi,bj)
186     C sum up contributions to form the right hand side
187     gTKE(I,J,K) = GGL90TKE(I,J,K,bi,bj)
188     & + deltaTggl90*(
189     & + KappaM*verticalShear
190     & - KappaM*Nsquare/TKEPrandtlNumber(I,J,K)
191     & - TKEdissipation
192     & )
193     ENDDO
194     ENDDO
195     ENDDO
196     C
197     C Implicit time step to update TKE for k=1,Nr; TKE(Nr+1)=0 by default
198     C
199     C set up matrix
200     C-- Old aLower
201     DO j=jMin,jMax
202     DO i=iMin,iMax
203     a(i,j,1) = 0. _d 0
204     ENDDO
205     ENDDO
206     DO k=2,Nr
207     km1=MAX(1,k-1)
208     DO j=jMin,jMax
209     DO i=iMin,iMax
210     a(i,j,k) = -deltaTggl90
211     & *recip_drF(km1)*recip_hFacI(i,j,k,bi,bj)
212     & *.5*(KappaE(i,j, k )+KappaE(i,j,km1))
213     & *recip_drC(k)
214     IF (recip_hFacI(i,j,km1,bi,bj).EQ.0.) a(i,j,k)=0.
215     ENDDO
216     ENDDO
217     ENDDO
218    
219     C-- Old aUpper
220     DO j=jMin,jMax
221     DO i=iMin,iMax
222     c(i,j,1) = 0. _d 0
223     c(i,j,Nr) = 0. _d 0
224     ENDDO
225     ENDDO
226     CML DO k=1,Nr-1
227     DO k=2,Nr
228     kp1=min(Nr,k+1)
229     DO j=jMin,jMax
230     DO i=iMin,iMax
231     c(i,j,k) = -deltaTggl90
232     & *recip_drF( k )*recip_hFacI(i,j,k,bi,bj)
233     & *.5*(KappaE(i,j,k)+KappaE(i,j,kp1))
234     & *recip_drC(k)
235     C IF (recip_hFacI(i,j,kp1,bi,bj).EQ.0.) c(i,j,k)=0.
236     ENDDO
237     ENDDO
238     ENDDO
239    
240     C-- Old aCenter
241     DO k=1,Nr
242     DO j=jMin,jMax
243     DO i=iMin,iMax
244     b(i,j,k) = 1. _d 0 - c(i,j,k) - a(i,j,k)
245     & + ab15*deltaTggl90*GGL90ceps*SQRT(GGL90TKE(I,J,K,bi,bj))
246     & /GGL90mixingLength(I,J,K)
247     ENDDO
248     ENDDO
249     ENDDO
250     C end set up matrix
251    
252     C
253     C Apply boundary condition
254     C
255     DO J=jMin,jMax
256     DO I=iMin,iMax
257     C estimate friction velocity uStar from surface forcing
258     uStarSquare = SQRT(
259     & ( .5*( surfaceForcingU(I, J, bi,bj)
260     & + surfaceForcingU(I+1,J, bi,bj) ) )**2
261     & + ( .5*( surfaceForcingV(I, J, bi,bj)
262     & + surfaceForcingV(I, J+1,bi,bj) ) )**2
263     & )
264     C Dirichlet surface boundary condition for TKE
265     gTKE(I,J,kSurf) = MAX(GGL90TKEmin,GGL90m2*uStarSquare)
266     & *maskC(I,J,kSurf,bi,bj)
267     C Dirichlet bottom boundary condition for TKE = GGL90TKEbottom
268     kBottom = MIN(MAX(kLowC(I,J,bi,bj),1),Nr)
269     gTKE(I,J,kBottom) = gTKE(I,J,kBottom)
270     & - GGL90TKEbottom*c(I,J,kBottom)
271     ENDDO
272     ENDDO
273     C
274     C solve tri-diagonal system, and store solution on gTKE (previously rhs)
275     C
276     CALL GGL90_SOLVE( bi, bj, iMin, iMax, jMin, jMax,
277     I a, b, c,
278     U gTKE,
279     I myThid )
280     C
281     C now update TKE
282     C
283     DO K=1,Nr
284     DO J=jMin,jMax
285     DO I=iMin,iMax
286     C impose minimum TKE to avoid numerical undershoots below zero
287     GGL90TKE(I,J,K,bi,bj) = MAX( gTKE(I,J,K), GGL90TKEmin )
288     & * maskC(I,J,K,bi,bj)
289     C
290     C end of time step
291     C
292     ENDDO
293     ENDDO
294     ENDDO
295     C
296     C compute viscosity coefficients
297     C
298     DO K=2,Nr
299     DO J=jMin,jMax
300     DO I=iMin,iMax
301     C Eq. (11), (18) and (21)
302     KappaM = GGL90ck*GGL90mixingLength(I,J,K)*
303     & SQRT( GGL90TKE(I,J,K,bi,bj) )
304     KappaH = KappaM/TKEPrandtlNumber(I,J,K)
305     C Set a minium (= background) value
306     KappaM = MAX(KappaM,viscAr)
307     KappaH = MAX(KappaH,diffKrT)
308     C Set a maximum and mask land point
309     GGL90viscAr(I,J,K,bi,bj) = MIN(KappaM,GGL90viscMax)
310     & * maskC(I,J,K,bi,bj)
311     GGL90diffKr(I,J,K,bi,bj) = MIN(KappaH,GGL90diffMax)
312     & * maskC(I,J,K,bi,bj)
313     ENDDO
314     ENDDO
315     C end third k-loop
316     ENDDO
317    
318     #endif /* ALLOW_GGL90 */
319    
320     RETURN
321     END
322    

  ViewVC Help
Powered by ViewVC 1.1.22