PUBLIC INTERFACE ~ PUBLIC ROUTINES

Module diag_grid_mod

Contact:  Seth Underwood
Reviewers: 
Change History: WebCVS Log

OVERVIEW

diag_grid_mod is a set of procedures to work with the model's global grid to allow regional output.

diag_grid_mod contains useful utilities for dealing with, mostly, regional output for grids other than the standard lat/lon grid. This module contains three public procedures diag_grid_init, which is shared globably in the diag_manager_mod, diag_grid_end which will free up memory used during the register field calls, and get_local_indexes. The send_global_grid procedure is called by the model that creates the global grid. send_global_grid needs to be called before any fields are registered that will output only regions. get_local_indexes is to be called by the diag_manager_mod to discover the global indexes defining a subregion on the tile. Change Log
September 2009
  • Single point region in Cubed Sphere
  • Single tile regions in the cubed sphere

OTHER MODULES USED

  constants_mod
        fms_mod
        mpp_mod
mpp_domains_mod

PUBLIC INTERFACE

diag_grid_init:
Send the global grid to the diag_manager_mod for regional output.
diag_grid_end:
Unallocate the diag_global_grid variable.
get_local_indexes:
Find the local start and local end indexes on the local PE for regional output.
get_local_indexes2:
Find the indices of the nearest grid point of the a-grid to the specified (lon,lat) location on the local PE. if desired point not within domain of local PE, return (0,0) as the indices.
gCirDistance:
Find the distance, along the geodesic, between two points.

PUBLIC ROUTINES

  1. diag_grid_init

    SUBROUTINE diag_grid_init (domain, glo_lat, glo_lon, aglo_lat, aglo_lon)
    DESCRIPTION
    In order for the diag_manager to do regional output for grids other than the standard lat/lon grid, the diag_manager_mod needs to know the the latitude and longitude values for the entire global grid. This procedure is the mechanism the models will use to share their grid with the diagnostic manager. This procedure needs to be called after the grid is created, and before the first call to register the fields.


    INPUT
    domain    The domain to which the grid data corresponds.
       [INTEGER]
    glo_lat    The latitude information for the grid tile.
       [REAL, DIMENSION(:,:)]
    glo_lon    The longitude information for the grid tile.
       [REAL, DIMENSION(:,:)]
    aglo_lat    The latitude information for the a-grid tile.
       [REAL, DIMENSION(:,:)]
    aglo_lon    The longitude information for the a-grid tile.
       [REAL, DIMENSION(:,:)]

  2. diag_grid_end

    SUBROUTINE diag_grid_end ()
    DESCRIPTION
    The diag_global_grid variable is only needed during the register field calls, and then only if there are fields requestion regional output. Once all the register fields calls are complete (before the first send_data call this procedure can be called to free up memory.


  3. get_local_indexes

    SUBROUTINE get_local_indexes (latStart, latEnd, lonStart, lonEnd, istart, iend, jstart, jend)
    DESCRIPTION
    Given a defined region, find the local indexes on the local PE surrounding the region.


    INPUT
    latStart    The minimum latitude value defining the region. This value must be less than latEnd, and be in the range [-90,90]
       [REAL]
    latEnd    The maximum latitude value defining the region. This value must be greater than latStart, and be in the range [-90,90]
       [REAL]
    lonStart    The western most longitude value defining the region. Possible ranges are either [-180,180] or [0,360].
       [REAL]
    lonEnd    The eastern most longitude value defining the region. Possible ranges are either [-180,180] or [0,360].
       [REAL]

    OUTPUT
    istart    The local start index on the local PE in the 'i' direction.
       [INTEGER]
    iend    The local end index on the local PE in the 'i' direction.
       [INTEGER]
    jstart    The local start index on the local PE in the 'j' direction.
       [INTEGER]
    jend    The local end index on the local PE in the 'j' direction.
       [INTEGER]

  4. get_local_indexes2

    SUBROUTINE get_local_indexes2 (lat, lon, iindex, jindex)
    DESCRIPTION
    Given a specified location, find the nearest a-grid indices on the local PE.


    INPUT
    lat    The requested latitude. This value must be in the range [-90,90]
       [REAL]
    lon    The requested longitude. Possible ranges are either [-180,180] or [0,360].
       [REAL]

    OUTPUT
    iindex    The local index on the local PE in the 'i' direction.
       [INTEGER]
    jindex    The local index on the local PE in the 'j' direction.
       [INTEGER]

  5. gCirDistance

    PURE ELEMENTAL REAL FUNCTION gCirDistance (lat1, lon1, lat2, lon2)
    DESCRIPTION
    aCirDistance will find the distance, along the geodesic, between two points defined by the (lat,lon) position of each point.


    INPUT
    lat1   Latitude of the first point
       [REAL]
    lon1   Longitude of the first point
       [REAL]
    lat2   Latitude of the second point
       [REAL]
    lon2   Longitude of the second point
       [REAL]

FUTURE PLANS


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