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Users/ModelInterfacing/AGRIF (diff) – NEMO

Changes between Version 24 and Version 25 of Users/ModelInterfacing/AGRIF


Ignore:
Timestamp:
2018-09-03T10:28:41+02:00 (6 years ago)
Author:
jchanut
Comment:

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  • Users/ModelInterfacing/AGRIF

    v24 v25  
    2727== Definition of the grid hierarchy 
    2828 
    29 An additional text file `AGRIF_FixedGrids.in` is required at run time. This is where the grid hierarchy is defined. An example of such a file, here taken from the [source:/NEMO/trunk/tests/VORTEX@10075 'VORTEX' test case], is given below:  
     29An additional text file `AGRIF_FixedGrids.in` is required at run time. This is where the grid hierarchy is defined. An example of such a file, here taken from the [source:/NEMO/trunk/tests/ICEDYN@10075 'ICEDYN' test case], is given below:  
    3030 
    31 [[IncludeSource(/NEMO/trunk/tests/VORTEX/EXPREF/AGRIF_FixedGrids.in, rev=9787, line_numbers=0)]] 
     31[[IncludeSource(/NEMO/trunk/tests/ICEDYN/EXPREF/AGRIF_FixedGrids.in, rev=10075, line_numbers=0)]] 
    3232 
    33 The first line indicates the number of zooms (1). The second line contains the starting and ending indices in both directions on the root grid (19 38 19 38) followed by the space and time refinement factors (3 3 3). The last line is the number of child grid nested in the refined region (0). A more complex example with telescoping grids can be found below and in the [source:/NEMO/trunk/cfgs/AGRIF_DEMO@10075 'AGRIF_DEMO' reference configuration directory] (NEMO 4.0 only).  
     33The first line indicates the number of zooms (1). The second line contains the starting and ending indices in both directions on the root grid (34 63 34 63) followed by the space and time refinement factors (3 3 3). The last line is the number of child grid nested in the refined region (0). A more complex example with telescoping grids can be found below and in the [source:/NEMO/trunk/cfgs/AGRIF_DEMO@10075 'AGRIF_DEMO' reference configuration directory] (NEMO 4.0 only).  
    3434 
    3535[[span(''Add some plots here with grid staggering and positioning ?'', style=background-color:lime)]] 
     
    7979 
    8080 * [[span(''Important notice concerning the change of ghost cells number:'', style=background-color:yellow)]] 
    81 The default number of ghost cells (i.e. the number of cells that serve as open boundary data provision) has been increased from 1 to 3 in NEMO 4.0. This allows to properly handle boundary conditions for numerical schemes that have a discretization order greater than 2. On the user point of view this does not change anything++ except in the definition of level 1 grids in the `AGRIF_FixedGrids.in` file. In order to retrieve exactly the position of a nested grid in NEMO 4.0 one has to shift indices by 2 points to the south-west. Taking the `VORTEX` example above for NEMO 4.0, the "old" NEMO 3.6 corresponding file would contain: 
     81The default number of ghost cells (i.e. the number of cells that serve as open boundary data provision) has been increased from 1 to 3 in NEMO 4.0. This allows to properly handle boundary conditions for numerical schemes that have a discretization order greater than 2. On the user point of view this does not change anything++ except in the definition of level 1 grids in the `AGRIF_FixedGrids.in` file. In order to retrieve exactly the position of a nested grid in NEMO 4.0 one has to shift indices by 2 points to the south-west. Taking the `ICEDYN` example above for NEMO 4.0, the "old" NEMO 3.6 corresponding file would contain: 
    8282 
    83 [[IncludeSource(/NEMO/releases/release-3.6/NEMOGCM/CONFIG/ORCA2_LIM/EXP00/AGRIF_FixedGrids.in, rev=9594)]] 
     83[[IncludeSource(/NEMO/trunk/tests/ICEDYN/EXPREF/AGRIF_FixedGrids.in_1ghost, rev=10075, line_numbers=0)]] 
    8484 
    85 ++ Output files are now greater by 4 points in each direction. 
     85++ Child grid output files are now greater by 4 points in each direction. 
    8686 
    8787 
     
    130130Debreu, L., P. Marchesiello, P. Penven and G. Cambon, 2012: Two-way nesting in split-explicit ocean models: Algorithms, implementation and validation. Ocean Modelling, 49-50, 1-21. [https://doi.org/10.1016/j.ocemod.2012.03.003] 
    131131 
    132 Penven, P., L. Debreu, P. Marchesiello and J. C. McWilliams, 2006: Evaluation and application of the ROMS 1-way embedding procedure to the central california upwelling system. Ocean Modelling, 12, 157-187. [https://doi.org/10.1016/j.ocemod.2005.05.002] 
     132Penven, P., L. Debreu, P. Marchesiello and J. C. Mc Williams, 2006: Evaluation and application of the ROMS 1-way embedding procedure to the central california upwelling system. Ocean Modelling, 12, 157-187. [https://doi.org/10.1016/j.ocemod.2005.05.002] 
    133133 
    134134Spall, M. A. and W. R. Holland, 1991: A Nested Primitive Equation Model for Oceanic Applications. J. Phys. Ocean., 21, 205-220. [https://doi.org/10.1175/1520-0485(1991)021<0205:ANPEMF>2.0.CO;2]