model/src/forward_step.F

C $Header: /u/gcmpack/MITgcm/model/src/forward_step.F,v 1.43 2002/12/06 20:10:58 cheisey Exp $
C $Name:  $

#include "CPP_OPTIONS.h"

CBOP
C     !ROUTINE: FORWARD_STEP
C     !INTERFACE:
      SUBROUTINE FORWARD_STEP( iloop, myTime, myIter, myThid )

C     !DESCRIPTION: \bv
C     *==================================================================
C     | SUBROUTINE forward_step
C     | o Run the ocean model and, optionally, evaluate a cost function.
C     *==================================================================
C     |
C     | THE_MAIN_LOOP is the toplevel routine for the Tangent Linear and
C     | Adjoint Model Compiler (TAMC). For this purpose the initialization
C     | of the model was split into two parts. Those parameters that do
C     | not depend on a specific model run are set in INITIALISE_FIXED,   
C     | whereas those that do depend on the specific realization are
C     | initialized in INITIALISE_VARIA.   
C     |
C     *==================================================================
C     \ev

C     !USES:
      IMPLICIT NONE
C     == Global variables ==
#include "SIZE.h"
#include "EEPARAMS.h"
#include "PARAMS.h"
#include "DYNVARS.h"
#include "FFIELDS.h"

#ifdef ALLOW_NONHYDROSTATIC
#include "CG3D.h"
#endif

#ifdef ALLOW_SHAP_FILT
#include "SHAP_FILT.h"
#endif
#ifdef ALLOW_ZONAL_FILT
#include "ZONAL_FILT.h"
#endif

#ifdef ALLOW_AUTODIFF_TAMC
# include "tamc.h"
# include "ctrl.h"
# include "ctrl_dummy.h"
# include "cost.h"
# include "EOS.h"
# ifdef INCLUDE_EXTERNAL_FORCING_PACKAGE
#  include "exf_fields.h"
#  ifdef ALLOW_BULK_FORCE
#   include "exf_constants.h"
#  endif
# endif
# ifdef ALLOW_OBCS
#  include "OBCS.h"
# endif
#endif

C     !LOCAL VARIABLES:
C     == Routine arguments ==
C     note: under the multi-threaded model myiter and 
C           mytime are local variables passed around as routine 
C           arguments. Although this is fiddly it saves the need to 
C           impose additional synchronisation points when they are 
C           updated.
C     myiter - iteration counter for this thread
C     mytime - time counter for this thread
C     mythid - thread number for this instance of the routine.
      integer iloop
      integer mythid 
      integer myiter
      _RL     mytime
      INTEGER bi,bj

CEOP


#ifdef ALLOW_AUTODIFF_TAMC
C--     Reset the model iteration counter and the model time.
        myiter = nIter0 + (iloop-1)
        mytime = startTime + float(iloop-1)*deltaTclock
#endif

#if (defined (ALLOW_AUTODIFF_TAMC) && defined (ALLOW_AUTODIFF_MONITOR))
C       Include call to a dummy routine. Its adjoint will be 
C       called at the proper place in the adjoint code.
C       The adjoint routine will print out adjoint values 
C       if requested. The location of the call is important, 
C       it has to be after the adjoint of the exchanges 
C       (DO_GTERM_BLOCKING_EXCHANGES).
        CALL DUMMY_IN_STEPPING( myTime, myIter, myThid )
        CALL DO_FIELDS_BLOCKING_EXCHANGES( myThid )
#endif

#ifdef EXACT_CONSERV
      IF (exactConserv) THEN
C--   Update etaH(n+1) :
         CALL TIMER_START('UPDATE_ETAH        [FORWARD_STEP]',mythid)
         CALL UPDATE_ETAH( myTime, myIter, myThid )
         CALL TIMER_STOP ('UPDATE_ETAH        [FORWARD_STEP]',mythid)
      ENDIF
#endif /* EXACT_CONSERV */ 

#ifdef NONLIN_FRSURF
C--   compute the future surface level thickness
C      according to etaH(n+1) 
        IF ( nonlinFreeSurf.GT.0) THEN
          CALL TIMER_START('CALC_SURF_DR      [FORWARD_STEP]',mythid)
          CALL CALC_SURF_DR(etaH, myTime, myIter, myThid )
          CALL TIMER_STOP ('CALC_SURF_DR      [FORWARD_STEP]',mythid)
        ENDIF
#endif /* NONLIN_FRSURF */


C--     Load forcing/external data fields.
#ifdef ALLOW_AUTODIFF_TAMC
c**************************************
#include "checkpoint_lev1_directives.h"
c**************************************
#endif


C--   Call external forcing package
cswdblk -- add ---
#ifdef ALLOW_BULK_FORCE
       CALL TIMER_START('BULKF_FIELDS_LOAD[THE_MAIN_LOOP]',mythid)
       CALL BULKF_FIELDS_LOAD( mytime, myiter, mythid )
       CALL TIMER_STOP ('BULKF_FIELDS_LOAD[THE_MAIN_LOOP]',mythid)
c calculate qnet and empmr (and wind stress)
       DO bj=myByLo(myThid),myByHi(myThid)
         DO bi=myBxLo(myThid),myBxHi(myThid)
          CALL BULKF_FORCING( bi,bj, mytime, myiter, mythid )
         ENDDO
       ENDDO
c     Update the tile edges.
       _EXCH_XY_R8(Qnet,   mythid)
       _EXCH_XY_R8(EmPmR,   mythid)
       CALL EXCH_UV_XY_RS(fu, fv, .TRUE., myThid)
C       _EXCH_XY_R8(fu     , mythid)
C       _EXCH_XY_R8(fv     , mythid)
cswdblk -- end add ---
#else
#ifdef INCLUDE_EXTERNAL_FORCING_PACKAGE
        IF ( .not. useSEAICE  ) THEN 
         CALL TIMER_START('EXF_GETFORCING     [FORWARD_STEP]',mythid)
         CALL EXF_GETFORCING( mytime, myiter, mythid )
         CALL TIMER_STOP ('EXF_GETFORCING     [FORWARD_STEP]',mythid)
        ENDIF
#else
        IF ( .not. useSEAICE  ) THEN 
         CALL TIMER_START('EXTERNAL_FIELDS_LOAD[FORWARD_STEP]',mythid)
         CALL EXTERNAL_FIELDS_LOAD( mytime, myiter, mythid )
         CALL TIMER_STOP ('EXTERNAL_FIELDS_LOAD[FORWARD_STEP]',mythid)
        ENDIF
#endif /* INCLUDE_EXTERNAL_FORCING_PACKAGE */
#endif


#ifdef ALLOW_SEAICE
C--   Call sea ice model to compute forcing/external data fields.
        IF ( useSEAICE ) THEN
         CALL TIMER_START('SEAICE_MODEL       [FORWARD_STEP]',myThid)
         CALL SEAICE_MODEL( myTime, myIter, myThid )
         CALL TIMER_STOP ('SEAICE_MODEL       [FORWARD_STEP]',myThid)
        ENDIF
#endif ALLOW_SEAICE

C--     Step forward fields and calculate time tendency terms.
        CALL TIMER_START('THERMODYNAMICS      [FORWARD_STEP]',mythid)
        CALL THERMODYNAMICS( myTime, myIter, myThid )
        CALL TIMER_STOP ('THERMODYNAMICS      [FORWARD_STEP]',mythid)

C--   do exchanges (needed for DYNAMICS) when using stagger time-step :
        CALL TIMER_START('BLOCKING_EXCHANGES  [FORWARD_STEP]',myThid)
        CALL DO_STAGGER_FIELDS_EXCHANGES( myTime, myIter, myThid )
        CALL TIMER_STOP ('BLOCKING_EXCHANGES  [FORWARD_STEP]',myThid)

#ifdef ALLOW_SHAP_FILT
       IF (useSHAP_FILT .AND. 
     &     staggerTimeStep .AND. shap_filt_TrStagg ) THEN
        CALL TIMER_START('SHAP_FILT           [FORWARD_STEP]',myThid)
        CALL SHAP_FILT_APPLY_TS( gT, gS, myTime, myIter, myThid )
        CALL TIMER_STOP ('SHAP_FILT           [FORWARD_STEP]',myThid)
       ENDIF
#endif
#ifdef ALLOW_ZONAL_FILT
       IF (useZONAL_FILT .AND. 
     &     staggerTimeStep .AND. zonal_filt_TrStagg ) THEN
        CALL TIMER_START('ZONAL_FILT_APPLY    [FORWARD_STEP]',myThid)
        CALL ZONAL_FILT_APPLY_TS( gT, gS, myThid )
        CALL TIMER_STOP ('ZONAL_FILT_APPLY    [FORWARD_STEP]',myThid)
      ENDIF
#endif   

C--     Step forward fields and calculate time tendency terms.
        IF ( momStepping ) THEN
        CALL TIMER_START('DYNAMICS            [FORWARD_STEP]',mythid)
        CALL DYNAMICS( myTime, myIter, myThid )
        CALL TIMER_STOP ('DYNAMICS            [FORWARD_STEP]',mythid)
        ENDIF

#ifdef ALLOW_NONHYDROSTATIC
C--   Step forward W field in N-H algorithm
        IF ( momStepping .AND. nonHydrostatic ) THEN
          CALL TIMER_START('CALC_GW          [FORWARD_STEP]',myThid)
          CALL CALC_GW(myThid)
          CALL TIMER_STOP ('CALC_GW          [FORWARD_STEP]',myThid)
        ENDIF
#endif

#ifdef NONLIN_FRSURF
C--   update hfacC,W,S and recip_hFac according to etaH(n+1) :
      IF ( nonlinFreeSurf.GT.0) THEN
        CALL TIMER_START('UPDATE_SURF_DR     [FORWARD_STEP]',mythid)
        CALL UPDATE_SURF_DR( myTime, myIter, myThid )
        CALL TIMER_STOP ('UPDATE_SURF_DR     [FORWARD_STEP]',myThid)
      ENDIF
C-    update also CG2D matrix (and preconditioner)
      IF ( momStepping .AND. nonlinFreeSurf.GT.2 ) THEN
        CALL TIMER_START('UPDATE_CG2D        [FORWARD_STEP]',mythid)
        CALL UPDATE_CG2D( myTime, myIter, myThid )
        CALL TIMER_STOP ('UPDATE_CG2D        [FORWARD_STEP]',mythid)
      ENDIF
#endif

C--   Apply Filters to u*,v* before SOLVE_FOR_PRESSURE
#ifdef ALLOW_SHAP_FILT
      IF (useSHAP_FILT .AND. shap_filt_uvStar) THEN
        CALL TIMER_START('SHAP_FILT           [FORWARD_STEP]',myThid)
        CALL SHAP_FILT_APPLY_UV( gUnm1,gVnm1, myTime,myIter,myThid )
        IF (implicDiv2Dflow.LT.1.) THEN
C--   Explicit+Implicit part of the Barotropic Flow Divergence
C      => Filtering of uVel,vVel is necessary
          CALL SHAP_FILT_APPLY_UV( uVel,vVel, myTime,myIter,myThid )
        ENDIF
        CALL TIMER_STOP ('SHAP_FILT           [FORWARD_STEP]',myThid)
      ENDIF
#endif
#ifdef ALLOW_ZONAL_FILT
      IF (useZONAL_FILT .AND. zonal_filt_uvStar) THEN
        CALL TIMER_START('ZONAL_FILT_APPLY    [FORWARD_STEP]',myThid)
        CALL ZONAL_FILT_APPLY_UV( gUnm1, gVnm1, myThid )
        IF (implicDiv2Dflow.LT.1.) THEN
C--   Explicit+Implicit part of the Barotropic Flow Divergence
C      => Filtering of uVel,vVel is necessary
          CALL ZONAL_FILT_APPLY_UV( uVel, vVel, myThid )
        ENDIF
        CALL TIMER_STOP ('ZONAL_FILT_APPLY    [FORWARD_STEP]',myThid)
      ENDIF
#endif  

C--   Solve elliptic equation(s).
C     Two-dimensional only for conventional hydrostatic or 
C     three-dimensional for non-hydrostatic and/or IGW scheme.
      IF ( momStepping ) THEN
      CALL TIMER_START('SOLVE_FOR_PRESSURE  [FORWARD_STEP]',myThid)
      CALL SOLVE_FOR_PRESSURE(myTime, myIter, myThid)
      CALL TIMER_STOP ('SOLVE_FOR_PRESSURE  [FORWARD_STEP]',myThid)
      ENDIF

#ifdef ALLOW_AUTODIFF_TAMC
cph This is needed because convective_adjustment calls
cph find_rho which may use pressure()
CADJ STORE pressure  = comlev1, key = ikey_dynamics
#endif
C--   Correct divergence in flow field and cycle time-stepping
C     arrays (for all fields) ; update time-counter
      myIter = nIter0 + iLoop
      myTime = startTime + deltaTClock * float(iLoop)
      CALL TIMER_START('THE_CORRECTION_STEP [FORWARD_STEP]',myThid)
      CALL THE_CORRECTION_STEP(myTime, myIter, myThid)
      CALL TIMER_STOP ('THE_CORRECTION_STEP [FORWARD_STEP]',myThid)

C--   Do "blocking" sends and receives for tendency "overlap" terms
c     CALL TIMER_START('BLOCKING_EXCHANGES  [FORWARD_STEP]',myThid)
c     CALL DO_GTERM_BLOCKING_EXCHANGES( myThid )
c     CALL TIMER_STOP ('BLOCKING_EXCHANGES  [FORWARD_STEP]',myThid)

C--   Do "blocking" sends and receives for field "overlap" terms
      CALL TIMER_START('BLOCKING_EXCHANGES  [FORWARD_STEP]',myThid)
      CALL DO_FIELDS_BLOCKING_EXCHANGES( myThid )
      CALL TIMER_STOP ('BLOCKING_EXCHANGES  [FORWARD_STEP]',myThid)

#ifdef ALLOW_FLT
C--   Calculate float trajectories
      IF (useFLT) THEN
        CALL TIMER_START('FLOATS            [FORWARD_STEP]',myThid)
        CALL FLT_MAIN(myIter,myTime, myThid)
        CALL TIMER_STOP ('FLOATS            [FORWARD_STEP]',myThid)
      ENDIF
#endif

#ifndef EXCLUDE_MONITOR
C--   Check status of solution (statistics, cfl, etc...)
      CALL TIMER_START('MONITOR             [FORWARD_STEP]',mythid)
      CALL MONITOR( myIter, myTime, myThid )
      CALL TIMER_STOP ('MONITOR             [FORWARD_STEP]',myThid)
#endif /* EXCLUDE_MONITOR */

C--   Do IO if needed.
      CALL TIMER_START('DO_THE_MODEL_IO     [FORWARD_STEP]',myThid)
      CALL DO_THE_MODEL_IO( myTime, myIter, myThid )
      CALL TIMER_STOP ('DO_THE_MODEL_IO     [FORWARD_STEP]',myThid)

C--   Save state for restarts
C     Note:    (jmc: is it still the case after ckp35 ?)
C     =====
C     Because of the ordering of the timestepping code and
C     tendency term code at end of loop model arrays hold
C     U,V,T,S  at "time-level" N but gu, gv, gs, gt, guNM1,... 
C     at "time-level" N+1/2 (guNM1 at "time-level" N+1/2 is 
C     gu at "time-level" N-1/2) and etaN at "time-level" N+1/2.
C      where N = I+timeLevBase-1
C     Thus a checkpoint contains U.0000000000, GU.0000000001 and 
C     etaN.0000000001 in the indexing scheme used for the model 
C     "state" files. This example is referred to as a checkpoint 
C     at time level 1 
      CALL TIMER_START('WRITE_CHECKPOINT    [FORWARD_STEP]',myThid)
      CALL WRITE_CHECKPOINT(
     &        .FALSE., myTime, myIter, myThid )
      CALL TIMER_STOP ('WRITE_CHECKPOINT    [FORWARD_STEP]',myThid)

      END
1	jmc	1.44	C $Header: /u/gcmpack/MITgcm/model/src/forward_step.F,v 1.43 2002/12/06 20:10:58 cheisey Exp $
2	adcroft	1.15	C $Name: $
3	adcroft	1.1
4			#include "CPP_OPTIONS.h"
5
6	cnh	1.22	CBOP
7			C !ROUTINE: FORWARD_STEP
8			C !INTERFACE:
9	adcroft	1.13	SUBROUTINE FORWARD_STEP( iloop, myTime, myIter, myThid )
10	heimbach	1.12
11	cnh	1.22	C !DESCRIPTION: \bv
12			C *==================================================================
13			C \| SUBROUTINE forward_step
14			C \| o Run the ocean model and, optionally, evaluate a cost function.
15			C *==================================================================
16			C \|
17			C \| THE_MAIN_LOOP is the toplevel routine for the Tangent Linear and
18			C \| Adjoint Model Compiler (TAMC). For this purpose the initialization
19			C \| of the model was split into two parts. Those parameters that do
20			C \| not depend on a specific model run are set in INITIALISE_FIXED,
21			C \| whereas those that do depend on the specific realization are
22			C \| initialized in INITIALISE_VARIA.
23			C \|
24			C *==================================================================
25			C \ev
26	adcroft	1.1
27	cnh	1.22	C !USES:
28			IMPLICIT NONE
29			C == Global variables ==
30	adcroft	1.1	#include "SIZE.h"
31			#include "EEPARAMS.h"
32			#include "PARAMS.h"
33			#include "DYNVARS.h"
34	heimbach	1.12	#include "FFIELDS.h"
35
36	adcroft	1.1	#ifdef ALLOW_NONHYDROSTATIC
37			#include "CG3D.h"
38			#endif
39
40	jmc	1.27	#ifdef ALLOW_SHAP_FILT
41			#include "SHAP_FILT.h"
42			#endif
43			#ifdef ALLOW_ZONAL_FILT
44			#include "ZONAL_FILT.h"
45			#endif
46
47	heimbach	1.12	#ifdef ALLOW_AUTODIFF_TAMC
48	heimbach	1.30	# include "tamc.h"
49			# include "ctrl.h"
50			# include "ctrl_dummy.h"
51			# include "cost.h"
52	heimbach	1.37	# include "EOS.h"
53	heimbach	1.30	# ifdef INCLUDE_EXTERNAL_FORCING_PACKAGE
54			# include "exf_fields.h"
55	cheisey	1.40	# ifdef ALLOW_BULK_FORCE
56	heimbach	1.30	# include "exf_constants.h"
57			# endif
58			# endif
59			# ifdef ALLOW_OBCS
60			# include "OBCS.h"
61			# endif
62	heimbach	1.12	#endif
63
64	cnh	1.22	C !LOCAL VARIABLES:
65			C == Routine arguments ==
66	adcroft	1.13	C note: under the multi-threaded model myiter and
67			C mytime are local variables passed around as routine
68			C arguments. Although this is fiddly it saves the need to
69			C impose additional synchronisation points when they are
70			C updated.
71			C myiter - iteration counter for this thread
72			C mytime - time counter for this thread
73			C mythid - thread number for this instance of the routine.
74	heimbach	1.12	integer iloop
75			integer mythid
76			integer myiter
77			_RL mytime
78	jmc	1.21	INTEGER bi,bj
79	heimbach	1.12
80	cnh	1.22	CEOP
81	heimbach	1.12
82
83			#ifdef ALLOW_AUTODIFF_TAMC
84	heimbach	1.14	C-- Reset the model iteration counter and the model time.
85	heimbach	1.12	myiter = nIter0 + (iloop-1)
86			mytime = startTime + float(iloop-1)*deltaTclock
87			#endif
88
89	heimbach	1.32	#if (defined (ALLOW_AUTODIFF_TAMC) && defined (ALLOW_AUTODIFF_MONITOR))
90	heimbach	1.16	C Include call to a dummy routine. Its adjoint will be
91			C called at the proper place in the adjoint code.
92			C The adjoint routine will print out adjoint values
93			C if requested. The location of the call is important,
94			C it has to be after the adjoint of the exchanges
95			C (DO_GTERM_BLOCKING_EXCHANGES).
96			CALL DUMMY_IN_STEPPING( myTime, myIter, myThid )
97	heimbach	1.26	CALL DO_FIELDS_BLOCKING_EXCHANGES( myThid )
98	heimbach	1.16	#endif
99
100	jmc	1.21	#ifdef EXACT_CONSERV
101			IF (exactConserv) THEN
102			C-- Update etaH(n+1) :
103	heimbach	1.36	CALL TIMER_START('UPDATE_ETAH [FORWARD_STEP]',mythid)
104	jmc	1.35	CALL UPDATE_ETAH( myTime, myIter, myThid )
105	heimbach	1.36	CALL TIMER_STOP ('UPDATE_ETAH [FORWARD_STEP]',mythid)
106	jmc	1.21	ENDIF
107			#endif /* EXACT_CONSERV */
108
109	jmc	1.18	#ifdef NONLIN_FRSURF
110			C-- compute the future surface level thickness
111	jmc	1.21	C according to etaH(n+1)
112	jmc	1.18	IF ( nonlinFreeSurf.GT.0) THEN
113	heimbach	1.36	CALL TIMER_START('CALC_SURF_DR [FORWARD_STEP]',mythid)
114	jmc	1.21	CALL CALC_SURF_DR(etaH, myTime, myIter, myThid )
115	heimbach	1.36	CALL TIMER_STOP ('CALC_SURF_DR [FORWARD_STEP]',mythid)
116	jmc	1.18	ENDIF
117	jmc	1.21	#endif /* NONLIN_FRSURF */
118	jmc	1.18
119	cheisey	1.38
120
121
122	adcroft	1.13	C-- Load forcing/external data fields.
123	heimbach	1.28	#ifdef ALLOW_AUTODIFF_TAMC
124			c**************************************
125			#include "checkpoint_lev1_directives.h"
126			c**************************************
127	heimbach	1.23	#endif
128	cheisey	1.38
129
130	heimbach	1.37	C-- Call external forcing package
131	cheisey	1.38	cswdblk -- add ---
132	cheisey	1.40	#ifdef ALLOW_BULK_FORCE
133	cheisey	1.38	CALL TIMER_START('BULKF_FIELDS_LOAD[THE_MAIN_LOOP]',mythid)
134			CALL BULKF_FIELDS_LOAD( mytime, myiter, mythid )
135			CALL TIMER_STOP ('BULKF_FIELDS_LOAD[THE_MAIN_LOOP]',mythid)
136			c calculate qnet and empmr (and wind stress)
137			DO bj=myByLo(myThid),myByHi(myThid)
138			DO bi=myBxLo(myThid),myBxHi(myThid)
139			CALL BULKF_FORCING( bi,bj, mytime, myiter, mythid )
140			ENDDO
141			ENDDO
142			c Update the tile edges.
143			_EXCH_XY_R8(Qnet, mythid)
144			_EXCH_XY_R8(EmPmR, mythid)
145	cheisey	1.43	CALL EXCH_UV_XY_RS(fu, fv, .TRUE., myThid)
146			C _EXCH_XY_R8(fu , mythid)
147			C _EXCH_XY_R8(fv , mythid)
148	cheisey	1.38	cswdblk -- end add ---
149	cheisey	1.42	#else
150	cheisey	1.39	#ifdef INCLUDE_EXTERNAL_FORCING_PACKAGE
151	cheisey	1.42	IF ( .not. useSEAICE ) THEN
152	heimbach	1.36	CALL TIMER_START('EXF_GETFORCING [FORWARD_STEP]',mythid)
153			CALL EXF_GETFORCING( mytime, myiter, mythid )
154			CALL TIMER_STOP ('EXF_GETFORCING [FORWARD_STEP]',mythid)
155			ENDIF
156	heimbach	1.12	#else
157	cheisey	1.42	IF ( .not. useSEAICE ) THEN
158	heimbach	1.36	CALL TIMER_START('EXTERNAL_FIELDS_LOAD[FORWARD_STEP]',mythid)
159			CALL EXTERNAL_FIELDS_LOAD( mytime, myiter, mythid )
160			CALL TIMER_STOP ('EXTERNAL_FIELDS_LOAD[FORWARD_STEP]',mythid)
161			ENDIF
162			#endif /* INCLUDE_EXTERNAL_FORCING_PACKAGE */
163	cheisey	1.42	#endif
164	cheisey	1.38
165
166
167	heimbach	1.36	#ifdef ALLOW_SEAICE
168	heimbach	1.37	C-- Call sea ice model to compute forcing/external data fields.
169	heimbach	1.36	IF ( useSEAICE ) THEN
170			CALL TIMER_START('SEAICE_MODEL [FORWARD_STEP]',myThid)
171	jmc	1.41	CALL SEAICE_MODEL( myTime, myIter, myThid )
172	heimbach	1.36	CALL TIMER_STOP ('SEAICE_MODEL [FORWARD_STEP]',myThid)
173			ENDIF
174			#endif ALLOW_SEAICE
175	adcroft	1.15
176			C-- Step forward fields and calculate time tendency terms.
177	heimbach	1.36	CALL TIMER_START('THERMODYNAMICS [FORWARD_STEP]',mythid)
178	adcroft	1.15	CALL THERMODYNAMICS( myTime, myIter, myThid )
179	heimbach	1.36	CALL TIMER_STOP ('THERMODYNAMICS [FORWARD_STEP]',mythid)
180	jmc	1.35
181			C-- do exchanges (needed for DYNAMICS) when using stagger time-step :
182	heimbach	1.36	CALL TIMER_START('BLOCKING_EXCHANGES [FORWARD_STEP]',myThid)
183	jmc	1.35	CALL DO_STAGGER_FIELDS_EXCHANGES( myTime, myIter, myThid )
184	heimbach	1.36	CALL TIMER_STOP ('BLOCKING_EXCHANGES [FORWARD_STEP]',myThid)
185	jmc	1.24
186			#ifdef ALLOW_SHAP_FILT
187	jmc	1.27	IF (useSHAP_FILT .AND.
188			& staggerTimeStep .AND. shap_filt_TrStagg ) THEN
189	heimbach	1.36	CALL TIMER_START('SHAP_FILT [FORWARD_STEP]',myThid)
190	jmc	1.24	CALL SHAP_FILT_APPLY_TS( gT, gS, myTime, myIter, myThid )
191	heimbach	1.36	CALL TIMER_STOP ('SHAP_FILT [FORWARD_STEP]',myThid)
192	jmc	1.24	ENDIF
193			#endif
194	jmc	1.27	#ifdef ALLOW_ZONAL_FILT
195			IF (useZONAL_FILT .AND.
196			& staggerTimeStep .AND. zonal_filt_TrStagg ) THEN
197	heimbach	1.36	CALL TIMER_START('ZONAL_FILT_APPLY [FORWARD_STEP]',myThid)
198	jmc	1.27	CALL ZONAL_FILT_APPLY_TS( gT, gS, myThid )
199	heimbach	1.36	CALL TIMER_STOP ('ZONAL_FILT_APPLY [FORWARD_STEP]',myThid)
200	jmc	1.27	ENDIF
201			#endif
202	heimbach	1.12
203	adcroft	1.13	C-- Step forward fields and calculate time tendency terms.
204	adcroft	1.19	IF ( momStepping ) THEN
205	heimbach	1.36	CALL TIMER_START('DYNAMICS [FORWARD_STEP]',mythid)
206	heimbach	1.12	CALL DYNAMICS( myTime, myIter, myThid )
207	heimbach	1.36	CALL TIMER_STOP ('DYNAMICS [FORWARD_STEP]',mythid)
208	adcroft	1.19	ENDIF
209	heimbach	1.12
210	adcroft	1.1	#ifdef ALLOW_NONHYDROSTATIC
211			C-- Step forward W field in N-H algorithm
212	adcroft	1.19	IF ( momStepping .AND. nonHydrostatic ) THEN
213	heimbach	1.36	CALL TIMER_START('CALC_GW [FORWARD_STEP]',myThid)
214	heimbach	1.12	CALL CALC_GW(myThid)
215	heimbach	1.36	CALL TIMER_STOP ('CALC_GW [FORWARD_STEP]',myThid)
216	heimbach	1.12	ENDIF
217	adcroft	1.1	#endif
218	jmc	1.18
219			#ifdef NONLIN_FRSURF
220	jmc	1.21	C-- update hfacC,W,S and recip_hFac according to etaH(n+1) :
221	jmc	1.18	IF ( nonlinFreeSurf.GT.0) THEN
222	heimbach	1.36	CALL TIMER_START('UPDATE_SURF_DR [FORWARD_STEP]',mythid)
223	jmc	1.18	CALL UPDATE_SURF_DR( myTime, myIter, myThid )
224	heimbach	1.36	CALL TIMER_STOP ('UPDATE_SURF_DR [FORWARD_STEP]',myThid)
225	jmc	1.18	ENDIF
226			C- update also CG2D matrix (and preconditioner)
227	jmc	1.33	IF ( momStepping .AND. nonlinFreeSurf.GT.2 ) THEN
228	heimbach	1.36	CALL TIMER_START('UPDATE_CG2D [FORWARD_STEP]',mythid)
229	jmc	1.18	CALL UPDATE_CG2D( myTime, myIter, myThid )
230	jmc	1.44	CALL TIMER_STOP ('UPDATE_CG2D [FORWARD_STEP]',mythid)
231	adcroft	1.19	ENDIF
232	jmc	1.18	#endif
233	adcroft	1.1
234	jmc	1.27	C-- Apply Filters to u,v before SOLVE_FOR_PRESSURE
235			#ifdef ALLOW_SHAP_FILT
236			IF (useSHAP_FILT .AND. shap_filt_uvStar) THEN
237	heimbach	1.36	CALL TIMER_START('SHAP_FILT [FORWARD_STEP]',myThid)
238	jmc	1.27	CALL SHAP_FILT_APPLY_UV( gUnm1,gVnm1, myTime,myIter,myThid )
239			IF (implicDiv2Dflow.LT.1.) THEN
240			C-- Explicit+Implicit part of the Barotropic Flow Divergence
241			C => Filtering of uVel,vVel is necessary
242			CALL SHAP_FILT_APPLY_UV( uVel,vVel, myTime,myIter,myThid )
243			ENDIF
244	heimbach	1.36	CALL TIMER_STOP ('SHAP_FILT [FORWARD_STEP]',myThid)
245	jmc	1.27	ENDIF
246			#endif
247			#ifdef ALLOW_ZONAL_FILT
248			IF (useZONAL_FILT .AND. zonal_filt_uvStar) THEN
249	heimbach	1.36	CALL TIMER_START('ZONAL_FILT_APPLY [FORWARD_STEP]',myThid)
250	jmc	1.27	CALL ZONAL_FILT_APPLY_UV( gUnm1, gVnm1, myThid )
251			IF (implicDiv2Dflow.LT.1.) THEN
252			C-- Explicit+Implicit part of the Barotropic Flow Divergence
253			C => Filtering of uVel,vVel is necessary
254			CALL ZONAL_FILT_APPLY_UV( uVel, vVel, myThid )
255			ENDIF
256	heimbach	1.36	CALL TIMER_STOP ('ZONAL_FILT_APPLY [FORWARD_STEP]',myThid)
257	jmc	1.27	ENDIF
258			#endif
259	heimbach	1.12
260	adcroft	1.1	C-- Solve elliptic equation(s).
261			C Two-dimensional only for conventional hydrostatic or
262			C three-dimensional for non-hydrostatic and/or IGW scheme.
263	adcroft	1.19	IF ( momStepping ) THEN
264	heimbach	1.36	CALL TIMER_START('SOLVE_FOR_PRESSURE [FORWARD_STEP]',myThid)
265	jmc	1.31	CALL SOLVE_FOR_PRESSURE(myTime, myIter, myThid)
266	heimbach	1.36	CALL TIMER_STOP ('SOLVE_FOR_PRESSURE [FORWARD_STEP]',myThid)
267	adcroft	1.19	ENDIF
268	adcroft	1.1
269	heimbach	1.37	#ifdef ALLOW_AUTODIFF_TAMC
270			cph This is needed because convective_adjustment calls
271			cph find_rho which may use pressure()
272			CADJ STORE pressure = comlev1, key = ikey_dynamics
273			#endif
274	adcroft	1.5	C-- Correct divergence in flow field and cycle time-stepping
275	jmc	1.7	C arrays (for all fields) ; update time-counter
276	heimbach	1.12	myIter = nIter0 + iLoop
277			myTime = startTime + deltaTClock * float(iLoop)
278	heimbach	1.36	CALL TIMER_START('THE_CORRECTION_STEP [FORWARD_STEP]',myThid)
279	heimbach	1.12	CALL THE_CORRECTION_STEP(myTime, myIter, myThid)
280	heimbach	1.36	CALL TIMER_STOP ('THE_CORRECTION_STEP [FORWARD_STEP]',myThid)
281	adcroft	1.5
282	adcroft	1.1	C-- Do "blocking" sends and receives for tendency "overlap" terms
283	heimbach	1.36	c CALL TIMER_START('BLOCKING_EXCHANGES [FORWARD_STEP]',myThid)
284	jmc	1.7	c CALL DO_GTERM_BLOCKING_EXCHANGES( myThid )
285	heimbach	1.36	c CALL TIMER_STOP ('BLOCKING_EXCHANGES [FORWARD_STEP]',myThid)
286	adcroft	1.5
287			C-- Do "blocking" sends and receives for field "overlap" terms
288	heimbach	1.36	CALL TIMER_START('BLOCKING_EXCHANGES [FORWARD_STEP]',myThid)
289	adcroft	1.5	CALL DO_FIELDS_BLOCKING_EXCHANGES( myThid )
290	heimbach	1.36	CALL TIMER_STOP ('BLOCKING_EXCHANGES [FORWARD_STEP]',myThid)
291	adcroft	1.20
292			#ifdef ALLOW_FLT
293			C-- Calculate float trajectories
294			IF (useFLT) THEN
295	heimbach	1.36	CALL TIMER_START('FLOATS [FORWARD_STEP]',myThid)
296	adcroft	1.20	CALL FLT_MAIN(myIter,myTime, myThid)
297	heimbach	1.36	CALL TIMER_STOP ('FLOATS [FORWARD_STEP]',myThid)
298	adcroft	1.20	ENDIF
299			#endif
300	heimbach	1.12
301			#ifndef EXCLUDE_MONITOR
302			C-- Check status of solution (statistics, cfl, etc...)
303	heimbach	1.36	CALL TIMER_START('MONITOR [FORWARD_STEP]',mythid)
304	heimbach	1.12	CALL MONITOR( myIter, myTime, myThid )
305	heimbach	1.36	CALL TIMER_STOP ('MONITOR [FORWARD_STEP]',myThid)
306	heimbach	1.12	#endif /* EXCLUDE_MONITOR */
307	adcroft	1.1
308	jmc	1.7	C-- Do IO if needed.
309	heimbach	1.36	CALL TIMER_START('DO_THE_MODEL_IO [FORWARD_STEP]',myThid)
310	heimbach	1.12	CALL DO_THE_MODEL_IO( myTime, myIter, myThid )
311	heimbach	1.36	CALL TIMER_STOP ('DO_THE_MODEL_IO [FORWARD_STEP]',myThid)
312	adcroft	1.1
313			C-- Save state for restarts
314	jmc	1.7	C Note: (jmc: is it still the case after ckp35 ?)
315	adcroft	1.1	C =====
316			C Because of the ordering of the timestepping code and
317			C tendency term code at end of loop model arrays hold
318			C U,V,T,S at "time-level" N but gu, gv, gs, gt, guNM1,...
319			C at "time-level" N+1/2 (guNM1 at "time-level" N+1/2 is
320	jmc	1.10	C gu at "time-level" N-1/2) and etaN at "time-level" N+1/2.
321	adcroft	1.1	C where N = I+timeLevBase-1
322			C Thus a checkpoint contains U.0000000000, GU.0000000001 and
323	jmc	1.10	C etaN.0000000001 in the indexing scheme used for the model
324	adcroft	1.1	C "state" files. This example is referred to as a checkpoint
325			C at time level 1
326	heimbach	1.36	CALL TIMER_START('WRITE_CHECKPOINT [FORWARD_STEP]',myThid)
327	adcroft	1.1	CALL WRITE_CHECKPOINT(
328	heimbach	1.12	& .FALSE., myTime, myIter, myThid )
329	heimbach	1.36	CALL TIMER_STOP ('WRITE_CHECKPOINT [FORWARD_STEP]',myThid)
330	adcroft	1.1
331			END