model/src/forward_step.F

C $Header: /u/gcmpack/models/MITgcmUV/model/src/forward_step.F,v 1.2 2000/06/21 19:09:00 adcroft Exp $

#include "CPP_OPTIONS.h"

      SUBROUTINE FORWARD_STEP(
     I                    doHalfStep, iLoop,
     U                    myCurrentTime, myCurrentIter,
     &                    myThid)
C     /==========================================================\
C     | SUBROUTINE FORWARD_STEP                                  |
C     | o Does one instance of the model time stepping           |
C     |   The time stepping loop in THE_MAIN_LOOP() calls        |
C     |   this routine                                           |
C     |==========================================================|
C     \==========================================================/
      IMPLICIT NONE
C
C     Call Tree
C     =========
C     
C      THE_MAIN_LOOP()
C       |
C  ==>  | ** Time stepping loop starts here **
C  |    |
C /|\   |-FORWARD_STEP
C  |    |  |
C  |    |  |--LOAD_EXTERNAL_DATA
C /|\   |  |   o Load and/or set time dependent forcing fields
C  |    |  |
C /|\   |  |--DYNAMICS
C  |    |  |   o Evaluate "forward" terms
C /|\   |  |
C  |    |  |--DO_THE_MODEL_IO
C /|\   |  |   o Write model state
C  |    |  |
C /|\   |  |--SOLVE_FOR_PRESSURE
C  |    |  |   o Find pressure field to keep flow non-divergent
C /|\   |  |
C  |    |  |--DO_GTERM_BLOCKING_EXCHANGES
C /|\   |  |   o Update overlap regions
C  |    |  |
C /|\   |  |--WRITE_CHECKPOINT
C  |    |  |   o Write restart file(s)
C /|\   |
C  |    |
C  |<== | ** Time stepping loop finishes here **
C

C     == Global variables ===
#include "SIZE.h"
#include "EEPARAMS.h"
#include "PARAMS.h"
#include "DYNVARS.h"
#include "CG2D.h"
#ifdef ALLOW_NONHYDROSTATIC
#include "CG3D.h"
#endif

C     == Routine arguments ==
C     doHalfStep - If .TRUE. then this is the last half step
C     iLoop         - Invocation count (counter in THE_MAIN_LOOP)
C     myCurrentIter - Iteration counter for this thread
C     myCurrentTime - Time counter for this thread
C     myThid - Thread number for this instance of the routine.
      LOGICAL doHalfStep
      INTEGER iLoop
      INTEGER myCurrentIter
      _RL     myCurrentTime
      INTEGER myThid  

C     == Local variables ==


C--   Load forcing/external data fields
      CALL TIMER_START('I/O (READ)         [FORWARD_STEP]',myThid)
      CALL EXTERNAL_FIELDS_LOAD( myCurrentTime, myCurrentIter, myThid )
      CALL TIMER_STOP ('I/O (READ)         [FORWARD_STEP]',myThid)

#ifdef INCLUDE_SHAPIRO_FILTER_CODE
C--   Step forward all tiles, filter and exchange.
      CALL TIMER_START('SHAP_FILT          [FORWARD_STEP]',myThid)
      CALL SHAP_FILT( myCurrentTime, myCurrentIter, myThid )
      CALL TIMER_STOP ('SHAP_FILT          [FORWARD_STEP]',myThid)
#endif

C--   Step forward fields and calculate time tendency terms
      CALL TIMER_START('DYNAMICS           [FORWARD_STEP]',myThid)
      CALL DYNAMICS( myCurrentTime, myCurrentIter, myThid )
      CALL TIMER_STOP ('DYNAMICS           [FORWARD_STEP]',myThid)

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

C--   Do IO if needed.
C     Note:
C     =====
C     At this point model arrays hold U,V,T,S  at "time-level" N 
C     and cg2d_x at "time-level" N-1/2 where N = I+timeLevBase-1. 
C     By convention this is taken to be the model "state". 
      CALL TIMER_START('I/O (WRITE)        [FORWARD_STEP]',myThid)
      CALL DO_THE_MODEL_IO(
     &        doHalfStep, myCurrentTime, myCurrentIter, myThid )
      CALL TIMER_STOP ('I/O (WRITE)        [FORWARD_STEP]',myThid)


      IF (.NOT. doHalfStep) THEN

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

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

c     myCurrentIter = myCurrentIter + 1
c     myCurrentTime = myCurrentTime + deltaTClock 
      myCurrentIter = nIter0 + iLoop
      myCurrentTime = startTime + deltaTClock * float(iLoop)

C--   Save state for restarts
C     Note:
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 cg2d_x at "time-level" N+1/2.
C      where N = I+timeLevBase-1
C     Thus a checkpoint contains U.0000000000, GU.0000000001 and 
C     cg2d_x.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('I/O (WRITE)        [FORWARD_STEP]',myThid)
      CALL WRITE_CHECKPOINT(
     &        .FALSE., myCurrentTime, myCurrentIter, myThid )
      CALL TIMER_STOP ('I/O (WRITE)        [FORWARD_STEP]',myThid)

      ENDIF

      RETURN
      END
1	heimbach	1.3	C $Header: /u/gcmpack/models/MITgcmUV/model/src/forward_step.F,v 1.2 2000/06/21 19:09:00 adcroft Exp $
2	adcroft	1.1
3			#include "CPP_OPTIONS.h"
4
5			SUBROUTINE FORWARD_STEP(
6			I doHalfStep, iLoop,
7			U myCurrentTime, myCurrentIter,
8			& myThid)
9			C /==========================================================\
10			C \| SUBROUTINE FORWARD_STEP \|
11			C \| o Does one instance of the model time stepping \|
12			C \| The time stepping loop in THE_MAIN_LOOP() calls \|
13			C \| this routine \|
14			C \|==========================================================\|
15			C \==========================================================/
16			IMPLICIT NONE
17			C
18			C Call Tree
19			C =========
20			C
21			C THE_MAIN_LOOP()
22			C \|
23			C ==> \| Time stepping loop starts here
24			C \| \|
25			C /\|\ \|-FORWARD_STEP
26			C \| \| \|
27			C \| \| \|--LOAD_EXTERNAL_DATA
28			C /\|\ \| \| o Load and/or set time dependent forcing fields
29			C \| \| \|
30			C /\|\ \| \|--DYNAMICS
31			C \| \| \| o Evaluate "forward" terms
32			C /\|\ \| \|
33			C \| \| \|--DO_THE_MODEL_IO
34			C /\|\ \| \| o Write model state
35			C \| \| \|
36			C /\|\ \| \|--SOLVE_FOR_PRESSURE
37			C \| \| \| o Find pressure field to keep flow non-divergent
38			C /\|\ \| \|
39			C \| \| \|--DO_GTERM_BLOCKING_EXCHANGES
40			C /\|\ \| \| o Update overlap regions
41			C \| \| \|
42			C /\|\ \| \|--WRITE_CHECKPOINT
43			C \| \| \| o Write restart file(s)
44			C /\|\ \|
45			C \| \|
46			C \|<== \| Time stepping loop finishes here
47			C
48
49			C == Global variables ===
50			#include "SIZE.h"
51			#include "EEPARAMS.h"
52			#include "PARAMS.h"
53			#include "DYNVARS.h"
54			#include "CG2D.h"
55			#ifdef ALLOW_NONHYDROSTATIC
56			#include "CG3D.h"
57			#endif
58
59			C == Routine arguments ==
60			C doHalfStep - If .TRUE. then this is the last half step
61			C iLoop - Invocation count (counter in THE_MAIN_LOOP)
62			C myCurrentIter - Iteration counter for this thread
63			C myCurrentTime - Time counter for this thread
64			C myThid - Thread number for this instance of the routine.
65			LOGICAL doHalfStep
66			INTEGER iLoop
67			INTEGER myCurrentIter
68			_RL myCurrentTime
69			INTEGER myThid
70
71			C == Local variables ==
72
73
74			C-- Load forcing/external data fields
75			CALL TIMER_START('I/O (READ) [FORWARD_STEP]',myThid)
76	heimbach	1.3	CALL EXTERNAL_FIELDS_LOAD( myCurrentTime, myCurrentIter, myThid )
77	adcroft	1.1	CALL TIMER_STOP ('I/O (READ) [FORWARD_STEP]',myThid)
78
79			#ifdef INCLUDE_SHAPIRO_FILTER_CODE
80			C-- Step forward all tiles, filter and exchange.
81			CALL TIMER_START('SHAP_FILT [FORWARD_STEP]',myThid)
82			CALL SHAP_FILT( myCurrentTime, myCurrentIter, myThid )
83			CALL TIMER_STOP ('SHAP_FILT [FORWARD_STEP]',myThid)
84			#endif
85
86			C-- Step forward fields and calculate time tendency terms
87			CALL TIMER_START('DYNAMICS [FORWARD_STEP]',myThid)
88			CALL DYNAMICS( myCurrentTime, myCurrentIter, myThid )
89			CALL TIMER_STOP ('DYNAMICS [FORWARD_STEP]',myThid)
90
91			#ifdef ALLOW_NONHYDROSTATIC
92			C-- Step forward W field in N-H algorithm
93			IF ( nonHydrostatic ) THEN
94			CALL TIMER_START('CALC_GW [FORWARD_STEP]',myThid)
95			CALL CALC_GW( myThid)
96			CALL TIMER_STOP ('CALC_GW [FORWARD_STEP]',myThid)
97			ENDIF
98			#endif
99
100			C-- Do IO if needed.
101			C Note:
102			C =====
103			C At this point model arrays hold U,V,T,S at "time-level" N
104			C and cg2d_x at "time-level" N-1/2 where N = I+timeLevBase-1.
105			C By convention this is taken to be the model "state".
106			CALL TIMER_START('I/O (WRITE) [FORWARD_STEP]',myThid)
107			CALL DO_THE_MODEL_IO(
108			& doHalfStep, myCurrentTime, myCurrentIter, myThid )
109			CALL TIMER_STOP ('I/O (WRITE) [FORWARD_STEP]',myThid)
110
111
112			IF (.NOT. doHalfStep) THEN
113
114			C-- Solve elliptic equation(s).
115			C Two-dimensional only for conventional hydrostatic or
116			C three-dimensional for non-hydrostatic and/or IGW scheme.
117			CALL TIMER_START('SOLVE_FOR_PRESSURE [FORWARD_STEP]',myThid)
118			CALL SOLVE_FOR_PRESSURE( myThid )
119			CALL TIMER_STOP ('SOLVE_FOR_PRESSURE [FORWARD_STEP]',myThid)
120
121			C-- Do "blocking" sends and receives for tendency "overlap" terms
122			CALL TIMER_START('BLOCKING_EXCHANGES [FORWARD_STEP]',myThid)
123			CALL DO_GTERM_BLOCKING_EXCHANGES( myThid )
124			CALL TIMER_STOP ('BLOCKING_EXCHANGES [FORWARD_STEP]',myThid)
125
126			c myCurrentIter = myCurrentIter + 1
127			c myCurrentTime = myCurrentTime + deltaTClock
128			myCurrentIter = nIter0 + iLoop
129			myCurrentTime = startTime + deltaTClock * float(iLoop)
130
131			C-- Save state for restarts
132			C Note:
133			C =====
134			C Because of the ordering of the timestepping code and
135			C tendency term code at end of loop model arrays hold
136			C U,V,T,S at "time-level" N but gu, gv, gs, gt, guNM1,...
137			C at "time-level" N+1/2 (guNM1 at "time-level" N+1/2 is
138			C gu at "time-level" N-1/2) and cg2d_x at "time-level" N+1/2.
139			C where N = I+timeLevBase-1
140			C Thus a checkpoint contains U.0000000000, GU.0000000001 and
141			C cg2d_x.0000000001 in the indexing scheme used for the model
142			C "state" files. This example is referred to as a checkpoint
143			C at time level 1
144			CALL TIMER_START('I/O (WRITE) [FORWARD_STEP]',myThid)
145			CALL WRITE_CHECKPOINT(
146			& .FALSE., myCurrentTime, myCurrentIter, myThid )
147			CALL TIMER_STOP ('I/O (WRITE) [FORWARD_STEP]',myThid)
148
149			ENDIF
150
151			RETURN
152			END