The vertical grid (Source File: updategrid.F90)

INTERFACE:

    subroutine updategrid(nlev,dt,zeta)

DESCRIPTION:

This subroutine calculates for each time step new layer thicknesses in order to fit them to the changing water depth. Three different grids can be specified:

1. Equidistant grid with possible zooming towards surface and bottom. The number of layers, nlev, and the zooming factors, ddu=$d_u$ and ddl=$d_l$, are specified in gotmmean.nml. Zooming is applied according to the formula

   $$h_k = D\frac{\mbox{tanh}\left( (d_l+d_u)\frac{k}{M}-d_l\right) +\mbox{tanh}(d_l)}{\mbox{tanh}(d_l)+\mbox{tanh}(d_u)}-1 \quad .$$ (11)

   
   

   From this formula, the following grids are constructed:

   • $d_l=d_u=0$ results in equidistant discretisations.
   • $d_l>0, d_u=0$ results in zooming near the bottom.
   • $d_l=0, d_u>0$ results in zooming near the surface.
   • $d_l>0, d_u>0$ results in double zooming nea both, the surface and the bottom.

2. Sigma-layers. The fraction that every layer occupies is read-in from file, see gotmmean.nml.
3. Cartesian layers. The height of every layer is read in from file, see gotmmean.nml. This method is not recommended when a varying sea surface is considered.

Furthermore, vertical velocity profiles are calculated here, if w_adv_method is 1 or 2, which has to be chosen in the w_advspec namelist in obs.nml. The profiles of vertical velocity are determined by two values, the height of maximum absolute value of vertical velocity, w_height, and the vertical velocity at this height, w_adv. From w_height, the vertical velocity is linearly decreasing towards the surface and the bottom, where is value is zero.

USES:

    use meanflow,     only: grid_ready
    use meanflow,     only: depth0,depth
    use meanflow,     only: ga,z,h,ho,ddu,ddl,grid_method
    use meanflow,     only: NN,SS,w_grid,grid_file,w
    use observations, only: zeta_method,w_adv_method
    use observations, only: w_adv,w_height,w_adv_discr
    IMPLICIT NONE

INPUT PARAMETERS:

    integer, intent(in)                 :: nlev
    REALTYPE, intent(in)                :: dt,zeta

REVISION HISTORY:

    Original author(s): Hans Burchard & Karsten Bolding
    $Log: updategrid.F90,v $
    Revision 1.20  2008-03-27 09:30:05  hb
    bug fix for w_height correction, bug found by Jorn Bruggeman
    Revision 1.19  2007-01-06 11:49:16  kbk
    namelist file extension changed .inp --> .nml
    Revision 1.18  2006-11-27 15:26:37  kbk
    initialise grid depending on grid_ready
    Revision 1.17  2006-11-24 15:13:41  kbk
    de-allocate memory and close open files
    Revision 1.16  2005-11-18 10:59:35  kbk
    removed unused variables - some left in parameter lists
    Revision 1.15  2005/11/15 11:39:32  lars
    documentation finish for print
    Revision 1.14  2005/08/25 19:41:33  hb
    small deviations between depth and depth0 tolerated now
    Revision 1.13  2005/08/15 20:23:40  hb
    Vertical advection profiles triangle-shaped also for
    temporally constant vertical velocity
    Revision 1.12  2005/06/27 13:44:07  kbk
    modified + removed traling blanks
    Revision 1.11  2004/08/18 11:46:19  lars
    updated documentation
    Revision 1.10  2003/07/23 10:52:52  hb
    proper initialisation of gridinit + cleaning
    Revision 1.9  2003/03/28 09:20:35  kbk
    added new copyright to files
    Revision 1.8  2003/03/28 08:56:56  kbk
    removed tabs
    Revision 1.7  2003/03/10 13:43:42  lars
    double definitions removed - to conform with DEC compiler
    Revision 1.6  2003/03/10 08:50:08  gotm
    Improved documentation and cleaned up code
    Revision 1.5  2002/02/08 08:33:44  gotm
    Manuel added support for reading grid distribution from file
    Revision 1.4  2001/11/27 19:51:49  gotm
    Cleaned
    Revision 1.3  2001/11/27 15:38:06  gotm
    Possible to read coordinate distribution from file
    Revision 1.1.1.1  2001/02/12 15:55:57  gotm
    initial import into CVS