/[MITgcm]/MITgcm/model/src/ini_cartesian_grid.F
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Revision 1.7 - (hide annotations) (download)
Thu Jul 2 14:16:24 1998 UTC (25 years, 10 months ago) by adcroft
Branch: MAIN
CVS Tags: checkpoint11, checkpoint13, checkpoint12, branch-point-rdot
Branch point for: branch-rdot
Changes since 1.6: +2 -73 lines
Re-arrangment of initialisation:
 o ini_grid is now called first and it sets up *only* the grid and
   coordinate system.
 o ini_depths then reads topography are can set it as a function of xC, yC.
 o ini_masks_etc then derives everything else (masks, lopping factors and
   recipricols).
This tidy-up is in preparation for the rDot transformation...(tense pause)!

1 adcroft 1.7 C $Header: /u/gcmpack/models/MITgcmUV/model/src/ini_cartesian_grid.F,v 1.6 1998/06/25 20:43:23 cnh Exp $
2 cnh 1.1
3     #include "CPP_EEOPTIONS.h"
4    
5     CStartOfInterface
6     SUBROUTINE INI_CARTESIAN_GRID( myThid )
7     C /==========================================================\
8     C | SUBROUTINE INI_CARTESIAN_GRID |
9     C | o Initialise model coordinate system |
10     C |==========================================================|
11     C | These arrays are used throughout the code in evaluating |
12     C | gradients, integrals and spatial avarages. This routine |
13     C | is called separately by each thread and initialise only |
14     C | the region of the domain it is "responsible" for. |
15     C | Notes: |
16     C | Two examples are included. One illustrates the |
17     C | initialisation of a cartesian grid. The other shows the |
18     C | inialisation of a spherical polar grid. Other orthonormal|
19     C | grids can be fitted into this design. In this case |
20     C | custom metric terms also need adding to account for the |
21     C | projections of velocity vectors onto these grids. |
22     C | The structure used here also makes it possible to |
23     C | implement less regular grid mappings. In particular |
24     C | o Schemes which leave out blocks of the domain that are |
25     C | all land could be supported. |
26     C | o Multi-level schemes such as icosohedral or cubic |
27     C | grid projections onto a sphere can also be fitted |
28     C | within the strategy we use. |
29     C | Both of the above also require modifying the support |
30     C | routines that map computational blocks to simulation |
31     C | domain blocks. |
32     C | Under the cartesian grid mode primitive distances in X |
33     C | and Y are in metres. Disktance in Z are in m or Pa |
34     C | depending on the vertical gridding mode. |
35     C \==========================================================/
36    
37     C === Global variables ===
38     #include "SIZE.h"
39     #include "EEPARAMS.h"
40     #include "PARAMS.h"
41     #include "GRID.h"
42    
43     C == Routine arguments ==
44     C myThid - Number of this instance of INI_CARTESIAN_GRID
45     INTEGER myThid
46     CEndOfInterface
47    
48     C == Local variables ==
49     C xG, yG - Global coordinate location.
50     C zG
51     C xBase - South-west corner location for process.
52     C yBase
53     C zUpper - Work arrays for upper and lower
54     C zLower cell-face heights.
55     C phi - Temporary scalar
56     C xBase - Temporaries for lower corner coordinate
57     C yBase
58     C iG, jG - Global coordinate index. Usually used to hold
59     C the south-west global coordinate of a tile.
60     C bi,bj - Loop counters
61     C zUpper - Temporary arrays holding z coordinates of
62     C zLower upper and lower faces.
63     C I,J,K
64     _RL xG, yG, zG
65     _RL phi
66     _RL zUpper(Nz), zLower(Nz)
67     _RL xBase, yBase
68     INTEGER iG, jG
69     INTEGER bi, bj
70     INTEGER I, J, K
71    
72     C-- Simple example of inialisation on cartesian grid
73     C-- First set coordinates of cell centers
74     C This operation is only performed at start up so for more
75     C complex configurations it is usually OK to pass iG, jG to a custom
76     C function and have it return xG and yG.
77     C Set up my local grid first
78 cnh 1.5 xC0 = 0. _d 0
79     yC0 = 0. _d 0
80 cnh 1.1 DO bj = myByLo(myThid), myByHi(myThid)
81     jG = myYGlobalLo + (bj-1)*sNy
82     DO bi = myBxLo(myThid), myBxHi(myThid)
83     iG = myXGlobalLo + (bi-1)*sNx
84     yBase = 0. _d 0
85     xBase = 0. _d 0
86     DO i=1,iG-1
87     xBase = xBase + delX(i)
88     ENDDO
89     DO j=1,jG-1
90     yBase = yBase + delY(j)
91     ENDDO
92     yG = yBase
93     DO J=1,sNy
94     xG = xBase
95     DO I=1,sNx
96     xc(I,J,bi,bj) = xG + delX(iG+i-1)*0.5 _d 0
97     yc(I,J,bi,bj) = yG + delY(jG+j-1)*0.5 _d 0
98     xG = xG + delX(iG+I-1)
99     dxF(I,J,bi,bj) = delX(iG+i-1)
100     dyF(I,J,bi,bj) = delY(jG+j-1)
101     ENDDO
102     yG = yG + delY(jG+J-1)
103     ENDDO
104     ENDDO
105     ENDDO
106     C Now sync. and get edge regions from other threads and/or processes.
107     C Note: We could just set the overlap regions ourselves here but
108     C exchanging edges is safer and is good practice!
109     _EXCH_XY_R4( xc, myThid )
110     _EXCH_XY_R4( yc, myThid )
111     _EXCH_XY_R4(dxF, myThid )
112     _EXCH_XY_R4(dyF, myThid )
113    
114     C-- Calculate separation between other points
115     C dxG, dyG are separations between cell corners along cell faces.
116     DO bj = myByLo(myThid), myByHi(myThid)
117     DO bi = myBxLo(myThid), myBxHi(myThid)
118     DO J=1,sNy
119     DO I=1,sNx
120     dxG(I,J,bi,bj) = (dxF(I,J,bi,bj)+dxF(I,J-1,bi,bj))*0.5 _d 0
121     dyG(I,J,bi,bj) = (dyF(I,J,bi,bj)+dyF(I-1,J,bi,bj))*0.5 _d 0
122     ENDDO
123     ENDDO
124     ENDDO
125     ENDDO
126     _EXCH_XY_R4(dxG, myThid )
127     _EXCH_XY_R4(dyG, myThid )
128     C dxV, dyU are separations between velocity points along cell faces.
129     DO bj = myByLo(myThid), myByHi(myThid)
130     DO bi = myBxLo(myThid), myBxHi(myThid)
131     DO J=1,sNy
132     DO I=1,sNx
133     dxV(I,J,bi,bj) = (dxG(I,J,bi,bj)+dxG(I-1,J,bi,bj))*0.5 _d 0
134     dyU(I,J,bi,bj) = (dyG(I,J,bi,bj)+dyG(I,J-1,bi,bj))*0.5 _d 0
135     ENDDO
136     ENDDO
137     ENDDO
138     ENDDO
139     _EXCH_XY_R4(dxV, myThid )
140     _EXCH_XY_R4(dyU, myThid )
141     C dxC, dyC is separation between cell centers
142     DO bj = myByLo(myThid), myByHi(myThid)
143     DO bi = myBxLo(myThid), myBxHi(myThid)
144     DO J=1,sNy
145     DO I=1,sNx
146     dxC(I,J,bi,bj) = (dxF(I,J,bi,bj)+dxF(I-1,J,bi,bj))*0.5 D0
147     dyC(I,J,bi,bj) = (dyF(I,J,bi,bj)+dyF(I,J-1,bi,bj))*0.5 D0
148     ENDDO
149     ENDDO
150     ENDDO
151     ENDDO
152     _EXCH_XY_R4(dxC, myThid )
153     _EXCH_XY_R4(dyC, myThid )
154     C Calculate vertical face area
155     DO bj = myByLo(myThid), myByHi(myThid)
156     DO bi = myBxLo(myThid), myBxHi(myThid)
157     DO J=1,sNy
158     DO I=1,sNx
159     zA(I,J,bi,bj) = dxF(I,J,bi,bj)*dyF(I,J,bi,bj)
160 cnh 1.6 tanPhiAtU(I,J,bi,bj) = 0. _d 0
161     tanPhiAtV(I,J,bi,bj) = 0. _d 0
162     ENDDO
163     ENDDO
164     ENDDO
165     ENDDO
166 adcroft 1.7 _EXCH_XY_R4 (zA , myThid )
167 cnh 1.5 _EXCH_XY_R4 (tanPhiAtU , myThid )
168     _EXCH_XY_R4 (tanPhiAtV , myThid )
169 cnh 1.1
170     C
171     RETURN
172     END

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