/[MITgcm]/MITgcm_contrib/darwin2/pkg/darwin/dic_surfforcing.F
ViewVC logotype

Annotation of /MITgcm_contrib/darwin2/pkg/darwin/dic_surfforcing.F

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


Revision 1.2 - (hide annotations) (download)
Wed Apr 20 19:19:27 2011 UTC (14 years, 6 months ago) by stephd
Branch: MAIN
CVS Tags: ctrb_darwin2_ckpt62w_20110426
Changes since 1.1: +15 -1 lines
o add fix to two bugs in handling water vapour pressure in carbonate chemisty
  and air-sea fluxes. Found by Val Bennington and Galen McKinley

1 jahn 1.1 #include "CPP_OPTIONS.h"
2     #include "PTRACERS_OPTIONS.h"
3     #include "DARWIN_OPTIONS.h"
4    
5     #ifdef ALLOW_PTRACERS
6     #ifdef ALLOW_DARWIN
7    
8     #ifdef ALLOW_CARBON
9    
10     CBOP
11     C !ROUTINE: DIC_SURFFORCING
12    
13     C !INTERFACE: ==========================================================
14     SUBROUTINE DIC_SURFFORCING( PTR_DIC , PTR_ALK, PTR_PO4, PTR_SIL,
15     O GDC,
16     I bi,bj,imin,imax,jmin,jmax,
17     I myIter,myTime,myThid)
18    
19     C !DESCRIPTION:
20     C Calculate the carbon air-sea flux terms
21     C following external_forcing_dic.F (OCMIP run) from Mick
22    
23     C !USES: ===============================================================
24     IMPLICIT NONE
25     #include "SIZE.h"
26     #include "DYNVARS.h"
27     #include "EEPARAMS.h"
28     #include "PARAMS.h"
29     #include "GRID.h"
30     #include "FFIELDS.h"
31     #include "DARWIN_SIZE.h"
32     #include "DARWIN_IO.h"
33     #include "DARWIN_FLUX.h"
34    
35     C !INPUT PARAMETERS: ===================================================
36     C myThid :: thread number
37     C myIter :: current timestep
38     C myTime :: current time
39     c PTR_DIC :: DIC tracer field
40     INTEGER myIter, myThid
41     _RL myTime
42     _RL PTR_DIC(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
43     _RL PTR_ALK(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
44     _RL PTR_PO4(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
45     _RL PTR_SIL(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
46     INTEGER iMin,iMax,jMin,jMax, bi, bj
47    
48     C !OUTPUT PARAMETERS: ===================================================
49     c GDC :: tendency due to air-sea exchange
50     _RL GDC(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
51    
52    
53     C !LOCAL VARIABLES: ====================================================
54     INTEGER I,J, kLev, it
55     C Number of iterations for pCO2 solvers...
56     C Solubility relation coefficients
57     _RL SchmidtNoDIC(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
58     _RL pCO2sat(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
59     _RL Kwexch(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
60     _RL pisvel(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
61     C local variables for carbon chem
62     _RL surfdic(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
63     _RL surfalk(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
64     _RL surfphos(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
65     _RL surfsi(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
66     _RL surfsalt(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
67     #ifdef ALLOW_OLD_VIRTUALFLUX
68     _RL VirtualFlux(1-OLx:sNx+OLx,1-OLy:sNy+OLy)
69     #endif
70     CEOP
71    
72     cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc
73    
74     kLev=1
75    
76     cc if coupled to atmsopheric model, use the
77     cc Co2 value passed from the coupler
78     c#ifndef USE_ATMOSCO2
79     cC PRE-INDUSTRIAL STEADY STATE pCO2 = 278.0 ppmv
80     c DO j=1-OLy,sNy+OLy
81     c DO i=1-OLx,sNx+OLx
82     c AtmospCO2(i,j,bi,bj)=278.0 _d -6
83     c ENDDO
84     c ENDDO
85     c#endif
86     C =================================================================
87     C determine inorganic carbon chem coefficients
88     DO j=jmin,jmax
89     DO i=imin,imax
90     surfdic(i,j) = max(10. _d 0 , PTR_DIC(i,j))*1e-3
91     & * maskC(i,j,kLev,bi,bj)
92     surfalk(i,j) = max(10. _d 0 , PTR_ALK(i,j))*1e-3
93     & * maskC(i,j,kLev,bi,bj)
94     surfphos(i,j) = max(1. _d -10, PTR_PO4(i,j))*1e-3
95     & * maskC(i,j,kLev,bi,bj)
96     surfsi(i,j) = max(1. _d -8, PTR_SIL(i,j))*1e-3
97     & * maskC(i,j,kLev,bi,bj)
98     surfsalt(i,j) = max(4. _d 0, salt(i,j,kLev,bi,bj))
99     ENDDO
100     ENDDO
101    
102     CALL CARBON_COEFFS(
103     I theta,salt,
104     I bi,bj,iMin,iMax,jMin,jMax,myThid)
105     C====================================================================
106    
107     DO j=jmin,jmax
108     DO i=imin,imax
109     C Compute AtmosP and Kwexch_Pre which are re-used for flux of O2
110    
111     #ifdef USE_PLOAD
112     C Convert anomalous pressure pLoad (in Pa) from atmospheric model
113     C to total pressure (in Atm)
114     C Note: it is assumed the reference atmospheric pressure is 1Atm=1013mb
115     C rather than the actual ref. pressure from Atm. model so that on
116     C average AtmosP is about 1 Atm.
117     AtmosP(i,j,bi,bj)= 1. _d 0 + pLoad(i,j,bi,bj)/Pa2Atm
118     #endif
119    
120     C Pre-compute part of exchange coefficient: pisvel*(1-fice)
121     C Schmidt number is accounted for later
122     pisvel(i,j)=0.337 _d 0 *wind(i,j,bi,bj)**2/3.6 _d 5
123     Kwexch_Pre(i,j,bi,bj) = pisvel(i,j)
124     & * (1. _d 0 - FIce(i,j,bi,bj))
125    
126     ENDDO
127     ENDDO
128    
129     c pCO2 solver...
130     C$TAF LOOP = parallel
131     DO j=jmin,jmax
132     C$TAF LOOP = parallel
133     DO i=imin,imax
134    
135     IF ( maskC(i,j,kLev,bi,bj).NE.0. _d 0 ) THEN
136     CALL CALC_PCO2_APPROX(
137     I theta(i,j,kLev,bi,bj),surfsalt(i,j),
138     I surfdic(i,j), surfphos(i,j),
139     I surfsi(i,j),surfalk(i,j),
140     I ak1(i,j,bi,bj),ak2(i,j,bi,bj),
141     I ak1p(i,j,bi,bj),ak2p(i,j,bi,bj),ak3p(i,j,bi,bj),
142     I aks(i,j,bi,bj),akb(i,j,bi,bj),akw(i,j,bi,bj),
143 stephd 1.2 I aksi(i,j,bi,bj),akf(i,j,bi,bj),
144     I ak0(i,j,bi,bj), fugf(i,j,bi,bj),
145     I ff(i,j,bi,bj),
146 jahn 1.1 I bt(i,j,bi,bj),st(i,j,bi,bj),ft(i,j,bi,bj),
147     U pH(i,j,bi,bj),pCO2(i,j,bi,bj),
148     I myThid )
149     ELSE
150     pCO2(i,j,bi,bj)=0. _d 0
151     ENDIF
152     ENDDO
153     ENDDO
154    
155    
156     DO j=jmin,jmax
157     DO i=imin,imax
158    
159     IF ( maskC(i,j,kLev,bi,bj).NE.0. _d 0 ) THEN
160     C calculate SCHMIDT NO. for CO2
161     SchmidtNoDIC(i,j) =
162     & sca1
163     & + sca2 * theta(i,j,kLev,bi,bj)
164     & + sca3 * theta(i,j,kLev,bi,bj)*theta(i,j,kLev,bi,bj)
165     & + sca4 * theta(i,j,kLev,bi,bj)*theta(i,j,kLev,bi,bj)
166     & *theta(i,j,kLev,bi,bj)
167    
168     C Determine surface flux (FDIC)
169     C first correct pCO2at for surface atmos pressure
170     pCO2sat(i,j) =
171     & AtmosP(i,j,bi,bj)*AtmospCO2(i,j,bi,bj)
172    
173     C then account for Schmidt number
174     Kwexch(i,j) = Kwexch_Pre(i,j,bi,bj)
175     & / sqrt(SchmidtNoDIC(i,j)/660.0 _d 0)
176    
177    
178 stephd 1.2 #ifdef WATERVAP_BUG
179 jahn 1.1 C Calculate flux in terms of DIC units using K0, solubility
180     C Flux = Vp * ([CO2sat] - [CO2])
181     C CO2sat = K0*pCO2atmos*P/P0
182     C Converting pCO2 to [CO2] using ff, as in CALC_PCO2
183     FluxCO2(i,j,bi,bj) =
184     & Kwexch(i,j)*(
185     & ak0(i,j,bi,bj)*pCO2sat(i,j) -
186     & ff(i,j,bi,bj)*pCO2(i,j,bi,bj)
187     & )
188 stephd 1.2 #else
189     C Corrected by Val Bennington Nov 2010 per G.A. McKinley's finding
190     C of error in application of water vapor correction
191     c Flux = kw*rho*(ff*pCO2atm-k0*FugFac*pCO2ocean)
192     FluxCO2(i,j,bi,bj) =
193     & Kwexch(i,j)*(
194     & ff(i,j,bi,bj)*pCO2sat(i,j) -
195     & pCO2(i,j,bi,bj)*fugf(i,j,bi,bj)
196     & *ak0(i,j,bi,bj) )
197     &
198     #endif
199 jahn 1.1 ELSE
200     FluxCO2(i,j,bi,bj) = 0. _d 0
201     ENDIF
202     C convert flux (mol kg-1 m s-1) to (mol m-2 s-1)
203     FluxCO2(i,j,bi,bj) = FluxCO2(i,j,bi,bj)/permil
204     c convert flux (mol m-2 s-1) to (mmol m-2 s-1)
205     FluxCO2(i,j,bi,bj) = FluxCO2(i,j,bi,bj)*1. _d 3
206    
207    
208     #ifdef ALLOW_OLD_VIRTUALFLUX
209     IF (maskC(i,j,kLev,bi,bj).NE.0. _d 0) THEN
210     c calculate virtual flux
211     c EminusPforV = dS/dt*(1/Sglob)
212     C NOTE: Be very careful with signs here!
213     C Positive EminusPforV => loss of water to atmos and increase
214     C in salinity. Thus, also increase in other surface tracers
215     C (i.e. positive virtual flux into surface layer)
216     C ...so here, VirtualFLux = dC/dt!
217     VirtualFlux(i,j)=gsm_DIC*surfaceForcingS(i,j,bi,bj)/gsm_s
218     c OR
219     c let virtual flux be zero
220     c VirtualFlux(i,j)=0.d0
221     c
222     ELSE
223     VirtualFlux(i,j)=0. _d 0
224     ENDIF
225     #endif /* ALLOW_OLD_VIRTUALFLUX */
226     ENDDO
227     ENDDO
228    
229     C update tendency
230     DO j=jmin,jmax
231     DO i=imin,imax
232     GDC(i,j)= recip_drF(kLev)*recip_hFacC(i,j,kLev,bi,bj)
233     & *(FluxCO2(i,j,bi,bj)
234     #ifdef ALLOW_OLD_VIRTUALFLUX
235     & + VirtualFlux(i,j)
236     #endif
237     & )
238     ENDDO
239     ENDDO
240    
241     RETURN
242     END
243     #endif /*ALLOW_CARBON*/
244    
245     #endif /*DARWIN*/
246     #endif /*ALLOW_PTRACERS*/
247     c ==================================================================

  ViewVC Help
Powered by ViewVC 1.1.22