== Ocean Mode Parameters ==
[[TracNav(doc/app/partoc|nocollapse)]]

[[NoteBox(note,This page is part of the **Ocean mode** documentation. \\ Since revision r3303 the ocean mode has been \\ modularized and has an own parameter namelist. \\It contains a listing of all PALM input parameters used to steer the ocean mode. \\ For an overview of all ocean-mode-related pages\, see the **[wiki:doc/tec/ocean ocean mode main page]**.)]]
'''NAMELIST group name:''' [=#d3par '''{{{ocean_parameters}}}''']
||='''Parameter Name'''  =||='''[../fortrantypes FORTRAN]\\[../fortrantypes Type]'''  =||='''Default\\Value'''  =||='''Explanation'''  =||
|----------------
{{{#!td style="vertical-align:top"
[=#bc_sa_t '''bc_sa_t''']
}}}
{{{#!td style="vertical-align:top"
C*20
}}}
{{{#!td style="vertical-align:top"
'neumann'
}}}
{{{#!td
Top boundary condition of the salinity.\\\\
Allowed are the values '' 'dirichlet' '' (sa(k=nz+1) does not change during the run) and '' 'neumann' '' (sa(k=nz+1)=sa(k=nz)).\\\\
When a constant salinity flux is used at the top boundary ([#top_salinityflux top_salinityflux]), '''bc_sa_t''' = '' 'neumann' '' must be used, because otherwise the resolved scale may contribute to the top flux so that a constant value cannot be guaranteed.
}}}
|----------------
{{{#!td style="vertical-align:top"
[=#bottom_salinityflux '''bottom_salinityflux''']
}}}
{{{#!td style="vertical-align:top"
R
}}}
{{{#!td style="vertical-align:top"
0.0
}}}
{{{#!td
Kinematic salinity flux near the surface (in psu m/s).\\\\ 
The respective salinity flux value is used as bottom (horizontally homogeneous) boundary condition for the salinity equation. This additionally requires that a Neumann condition must be used for the salinity, which is currently the only available condition.
}}}
|----------------
{{{#!td style="vertical-align:top;width: 150px"
[=#salinity '''salinity''']
}}}
{{{#!td style="vertical-align:top;width: 50px"
L
}}}
{{{#!td style="vertical-align:top;width: 75px"
.T.
}}}
{{{#!td
Parameter to switch on/off calculation of salinity equation.

You may set '''salinity = .FALSE.''' in case of ocean mixed layer studies (where the turbulent layer is shallow), in order to save CPU time. In that case, a constant salinity as given by [#sa_surface sa_surface] is assumed when calculating the equation of state.

In case of '''salinity''' = ''.F.'' non-zero values for parameters [#bottom_salinityflux bottom_salinityflux] and [#top_salinityflux top_salinityflux] are not allowed. 
}}}
|----------------
{{{#!td style="vertical-align:top;width: 150px"
[=#sa_surface '''sa_surface''']
}}}
{{{#!td style="vertical-align:top;width: 50px"
R
}}}
{{{#!td style="vertical-align:top;width: 75px"
35.0
}}}
{{{#!td
Surface salinity (in psu).\\\\ 
This parameter assigns the value of the salinity '''sa''' at the sea surface (k=[#nzt nzt]). Starting from this value, the initial vertical salinity profile is constructed from the surface down to the bottom of the model (k=0) by using [#sa_vertical_gradient sa_vertical_gradient] and [#sa_vertical_gradient_level sa_vertical_gradient_level].
}}}
|----------------
{{{#!td style="vertical-align:top;width: 150px"
[=#sa_vertical_gradient '''sa_vertical_gradient''']
}}}
{{{#!td style="vertical-align:top;width: 50px"
R(10)
}}}
{{{#!td style="vertical-align:top;width: 75px"
10 * 0.0
}}}
{{{#!td
Salinity gradient(s) of the initial salinity profile (in psu / 100 m).\\\\
This salinity gradient holds starting from the height level defined by [#sa_vertical_gradient_level sa_vertical_gradient_level] (precisely: for all uv levels k where zu(k) < sa_vertical_gradient_level, sa_init(k) is set: sa_init(k) = sa_init(k+1) - dzu(k+1) * '''sa_vertical_gradient''') down to the bottom boundary or down to the next height level defined by sa_vertical_gradient_level. A total of 10 different gradients for 11 height intervals (10 intervals if sa_vertical_gradient_level(1) = 0.0) can be assigned. The surface salinity at k=[#nzt nzt] is assigned via [#sa_surface sa_surface].\\\\
'''Example:'''\\\\
      '''sa_vertical_gradient''' = ''1.0,'' ''0.5,''\\
      [#sa_vertical_gradient_level sa_vertical_gradient_level] = ''-500.0,'' ''-1000.0,''\\\\
That defines the salinity to be constant down to z = -500.0 m with a salinity given by sa_surface. For -500.0 m < z <= -1000.0 m the salinity gradient is 1.0 psu / 100 m and for z < -1000.0 m down to the bottom boundary it is 0.5 psu / 100 m (it is assumed that the assigned height levels correspond with uv levels).
}}}
|----------------
{{{#!td style="vertical-align:top;width: 150px"
[=#sa_vertical_gradient_level '''sa_vertical_gradient_level''']
}}}
{{{#!td style="vertical-align:top;width: 50px"
R(10)
}}}
{{{#!td style="vertical-align:top;width: 75px"
10 * 0.0
}}}
{{{#!td
Height level from which on the salinity gradient defined by [#sa_vertical_gradient sa_vertical_gradient] is effective (in m).\\\\
The height levels have to be assigned in descending order. The default values result in a constant salinity profile regardless of the values of sa_vertical_gradient (unless the bottom boundary of the model is lower than -100000.0 m). For the piecewise construction of salinity profiles see [#sa_vertical_gradient sa_vertical_gradient].
}}}
|----------------
{{{#!td style="vertical-align:top"
[=#stokes_waveheight '''stokes_waveheight''']
}}}
{{{#!td style="vertical-align:top"
R
}}}
{{{#!td style="vertical-align:top"
0.0
}}}
{{{#!td
Parameter to switch on and set the effects of Langmuir circulation in PALM's ocean mode.

The effects of Langmuir circulation are considered in PALM by the Craik-Leibovich vortex force and the Stokes drift velocity, as described in Noh et al. (2004), JPO. In order to switch these effects on, you need to set both parameters, '''stokes_waveheight''' as well as [#stokes_wavelength stokes_wavelength] to a non-zero positive value. '''stokes_waveheight''' sets the height of the ocean surface waves to be used for calculating the vertical profile of the Stokes drift velocity. The direction of the Stokes drift velocity is derived from parameters [wiki:doc/app/inipar#top_momentumflux_u top_momentumflux_u] and [wiki:doc/app/inipar#top_momentumflux_v top_momentumflux_v], which define the wind stress at the ocean surface.
}}}
|----------------
{{{#!td style="vertical-align:top;width: 150px"
[=#stokes_wavelength '''stokes_wavelength''']
}}}
{{{#!td style="vertical-align:top;width: 50px"
R
}}}
{{{#!td style="vertical-align:top;width: 75px"
0.0
}}}
{{{#!td
Parameter to switch on and set the effects of Langmuir circulation in PALM's ocean mode.

The effects of Langmuir circulation are considered in PALM by the Craik-Leibovich vortex force and the Stokes drift velocity, as described in Noh et al. (2004), JPO. In order to switch these effects on, you need to set both parameters, '''stokes_wavelength''' as well as [#stokes_waveheight stokes_waveheight] to a non-zero positive value. '''stokes_wavelength''' sets the wave length of the ocean surface waves to be used for calculating the vertical profile of the Stokes drift velocity. The direction of the Stokes drift velocity is derived from parameters [wiki:doc/app/inipar#top_momentumflux_u top_momentumflux_u] and [wiki:doc/app/inipar#top_momentumflux_v top_momentumflux_v], which define the wind stress at the ocean surface.

}}}
|----------------
{{{#!td style="vertical-align:top"
[=#top_salinityflux '''top_salinityflux''']
}}}
{{{#!td style="vertical-align:top"
R
}}}
{{{#!td style="vertical-align:top"
no prescribed\\
salinityflux
}}}
{{{#!td
Kinematic salinity flux at the top boundary, i.e. the sea surface (in psu m/s).\\\\
If a value is assigned to this parameter, the internal surface heat flux array is initialized with the value of '''top_salinityflux''' as top (horizontally homogeneous) boundary condition for the salinity equation. This additionally requires that a Neumann condition must be used for the salinity (see [#bc_sa_t bc_sa_t]), because otherwise the resolved scale may contribute to the top flux so that a constant flux value cannot be guaranteed.\\\\
'''Note:'''\\
The application of a salinity flux at the model top additionally requires the setting of initial parameter [wiki:doc/app/inipar#use_top_fluxes use_top_fluxes] = ''.T.''.\\\\
See also [#bottom_salinityflux bottom_salinityflux].
}}}
|----------------
{{{#!td style="vertical-align:top;width: 150px"
[=#wall_salinityflux '''wall_salinityflux''']
}}}
{{{#!td style="vertical-align:top;width: 50px"
R(0:5)
}}}
{{{#!td style="vertical-align:top;width: 75px"
6 * 0.0
}}}
{{{#!td
Prescribed kinematic salinity flux in Psu m/s at the six topography faces:\\\\
'''wall_salinityflux'''(0)    top face\\
'''wall_salinityflux'''(1)    left face\\
'''wall_salinityflux'''(2)    right face\\
'''wall_salinityflux'''(3)    south face\\
'''wall_salinityflux'''(4)    north face\\
'''wall_salinityflux'''(5)    bottom face\\\\
This parameter applies only in case of a non-flat topography. Prescribing wall_salinityflux additionally requires setting of [#bottom_salinityflux bottom_salinityflux]. Furthermore, please note that wall_salinityflux(0) only describes the kinematic flux at non-zero height. At zero-height (surface) the kinematic flux is given by [#bottom_salinityflux bottom_salinityflux] instead.
}}}
|----------------
{{{#!td style="vertical-align:top;width: 150px"
[=#wave_breaking '''wave_breaking''']
}}}
{{{#!td style="vertical-align:top;width: 50px"
L
}}}
{{{#!td style="vertical-align:top;width: 75px"
.F.
}}}
{{{#!td
Parameter to switch on turbulence generation by wave breaking.

You need to set '''wave_breaking = .T.''' to switch on turbulence generation by wave breaking at the ocean surface. This way, random perturbation are added to the horizontal velocity components at the top model layer (k = nzt). The parameterization is realized as described in Noh et al. (2004), JPO.

'''WARNING: The implemented parameterization is designed for a vertical grid spacing of dz = 1.25m and time steps of about 4 s. It will probably fail for other setups.'''
}}}