Initialization parameters

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Mode:

Parameter Name	Type	Default Value	Explanation
ocean	L	.F.	Parameter to switch on ocean runs. By default PALM is configured to simulate atmospheric flows. However, starting from version 3.3, ocean = .T. allows simulation of ocean turbulent flows. Setting this switch has several effects: An additional prognostic equation for salinity is solved. Potential temperature in buoyancy and stability-related terms is replaced by potential density. Potential density is calculated from the equation of state for seawater after each timestep, using the algorithm proposed by Jackett et al. (2006, J. Atmos. Oceanic Technol., 23, 1709-1728). So far, only the initial hydrostatic pressure is entered into this equation. z=0 (sea surface) is assumed at the model top (vertical grid index k=nzt on the w-grid), with negative values of z indicating the depth. Initial profiles are constructed (e.g. from pt_vertical_gradient / pt_vertical_gradient_level) starting from the sea surface, using surface values given by pt_surface, sa_surface, ug_surface, and vg_surface. Zero salinity flux is used as default boundary condition at the bottom of the sea. If switched on, random perturbations are by default imposed to the upper model domain from zu(nzt*2/3) to zu(nzt-3). Relevant parameters to be exclusively used for steering ocean runs are bc_sa_t, bottom_salinityflux, sa_surface, sa_vertical_gradient, sa_vertical_gradient_level, and top_salinityflux. Section 4.4.2 gives an example for appropriate settings of these and other parameters neccessary for ocean runs. ocean = .T. does not allow settings of timestep_scheme = 'leapfrog' or 'leapfrog+euler' as well as scalar_advec = 'ups-scheme' .
[=#<insert_parameter_name> <insert_parameter_name>]	<insert type>	<insert value>	<insert explanation>

Grid:

Parameter Name	Type	Default Value	Explanation
averaging_interval	R	0.0	Averaging interval for all output of temporally averaged data (in s). This parameter defines the time interval length for temporally averaged data (vertical profiles, spectra, 2d cross-sections, 3d volume data). By default, data are not subject to temporal averaging. The interval length is limited by the parameter #dt_data_output_av dt_data_output_av. In any case, averaging_interval <= dt_data_output_av must hold. If an interval is defined, then by default the average is calculated from the data values of all timesteps lying within this interval. The number of time levels entering into the average can be reduced with the parameter dt_averaging_input. If an averaging interval can not be completed at the end of a run, it will be finished at the beginning of the next restart run. Thus for restart runs, averaging intervals do not necessarily begin at the beginning of the run. Parameters averaging_interval_pr and averaging_interval_sp can be used to define different averaging intervals for vertical profile data and spectra, respectively.
[=#<insert_parameter_name> <insert_parameter_name>]	<insert type>	<insert value>	<insert explanation>

Numerics:

Parameter Name	Type	Default Value	Explanation
averaging_interval	R	0.0	Averaging interval for all output of temporally averaged data (in s). This parameter defines the time interval length for temporally averaged data (vertical profiles, spectra, 2d cross-sections, 3d volume data). By default, data are not subject to temporal averaging. The interval length is limited by the parameter #dt_data_output_av dt_data_output_av. In any case, averaging_interval <= dt_data_output_av must hold. If an interval is defined, then by default the average is calculated from the data values of all timesteps lying within this interval. The number of time levels entering into the average can be reduced with the parameter dt_averaging_input. If an averaging interval can not be completed at the end of a run, it will be finished at the beginning of the next restart run. Thus for restart runs, averaging intervals do not necessarily begin at the beginning of the run. Parameters averaging_interval_pr and averaging_interval_sp can be used to define different averaging intervals for vertical profile data and spectra, respectively.
[=#<insert_parameter_name> <insert_parameter_name>]	<insert type>	<insert value>	<insert explanation>

Boundary conditions:

Parameter Name	Type	Default Value	Explanation
bc_e_b	C*20	'neumann'	Bottom boundary condition of the TKE. bc_e_b may be set to 'neumann' or '(u*)2+neumann' . bc_e_b = 'neumann' yields to e(k=0)=e(k=1) (Neumann boundary condition), where e(k=1) is calculated via the prognostic TKE equation. Choice of '(u*)2+neumann' also yields to e(k=0)=e(k=1), but the TKE at the Prandtl-layer top (k=1) is calculated diagnostically by e(k=1)=(us/0.1)2. However, this is only allowed if a Prandtl-layer is used (#prandtl_layer). If this is not the case, a warning is given and bc_e_b is reset to 'neumann' . At the top boundary a Neumann boundary condition is generally used: (e(nz+1) = e(nz)).
[=#<insert_parameter_name> <insert_parameter_name>]	<insert type>	<insert value>	<insert explanation>

Initialization:

Parameter Name	Type	Default Value	Explanation
averaging_interval	R	0.0	Averaging interval for all output of temporally averaged data (in s). This parameter defines the time interval length for temporally averaged data (vertical profiles, spectra, 2d cross-sections, 3d volume data). By default, data are not subject to temporal averaging. The interval length is limited by the parameter #dt_data_output_av dt_data_output_av. In any case, averaging_interval <= dt_data_output_av must hold. If an interval is defined, then by default the average is calculated from the data values of all timesteps lying within this interval. The number of time levels entering into the average can be reduced with the parameter dt_averaging_input. If an averaging interval can not be completed at the end of a run, it will be finished at the beginning of the next restart run. Thus for restart runs, averaging intervals do not necessarily begin at the beginning of the run. Parameters averaging_interval_pr and averaging_interval_sp can be used to define different averaging intervals for vertical profile data and spectra, respectively.
[=#<insert_parameter_name> <insert_parameter_name>]	<insert type>	<insert value>	<insert explanation>

Topography:

Parameter Name	Type	Default Value	Explanation
topography	C*40	'flat'	Topography mode. The user can choose between the following modes: 'flat' Flat surface. 'single_building' Flow around a single rectangular building mounted on a flat surface. The building size and location can be specified by the parameters building_height, building_length_x, building_length_y, building_wall_left and building_wall_south. 'single_street_canyon' Flow over a single, quasi-2D street canyon of infinite length oriented either in x- or in y-direction. The canyon size, orientation and location can be specified by the parameters canyon_height plus either canyon_width_x and canyon_wall_left or canyon_width_y and canyon_wall_south. 'read_from_file' Flow around arbitrary topography. This mode requires the input file TOPOGRAPHY_DATA. This file contains the arbitrary topography height information in m. These data must exactly match the horizontal grid. Alternatively, the user may add code to the user interface subroutine user_init_grid to allow further topography modes. These require to explicitly set the topography_grid_convention to either 'cell_edge' or 'cell_center'. Non-flat topography modes may assign a kinematic sensible wall_heatflux and a kinematic wall_humidityflux (requires humidity = .T.) or a wall_scalarflux (requires passive_scalar = .T.) at the five topography faces. All non-flat topography modes require the use of momentum_advec = scalar_advec = 'pw-scheme', psolver /= 'sor', alpha_surface = 0.0, galilei_transformation = .F., cloud_physics = .F., cloud_droplets = .F., and prandtl_layer = .T.. Note that an inclined model domain requires the use of topography = 'flat' and a nonzero alpha_surface.
[=#<insert_parameter_name> <insert_parameter_name>]	<insert type>	<insert value>	<insert explanation>

Canopy:

Parameter Name	Type	Default Value	Explanation
averaging_interval	R	0.0	Averaging interval for all output of temporally averaged data (in s). This parameter defines the time interval length for temporally averaged data (vertical profiles, spectra, 2d cross-sections, 3d volume data). By default, data are not subject to temporal averaging. The interval length is limited by the parameter #dt_data_output_av dt_data_output_av. In any case, averaging_interval <= dt_data_output_av must hold. If an interval is defined, then by default the average is calculated from the data values of all timesteps lying within this interval. The number of time levels entering into the average can be reduced with the parameter dt_averaging_input. If an averaging interval can not be completed at the end of a run, it will be finished at the beginning of the next restart run. Thus for restart runs, averaging intervals do not necessarily begin at the beginning of the run. Parameters averaging_interval_pr and averaging_interval_sp can be used to define different averaging intervals for vertical profile data and spectra, respectively.
[=#<insert_parameter_name> <insert_parameter_name>]	<insert type>	<insert value>	<insert explanation>

Others:

Parameter Name	Type	Default Value	Explanation
averaging_interval	R	0.0	Averaging interval for all output of temporally averaged data (in s). This parameter defines the time interval length for temporally averaged data (vertical profiles, spectra, 2d cross-sections, 3d volume data). By default, data are not subject to temporal averaging. The interval length is limited by the parameter #dt_data_output_av dt_data_output_av. In any case, averaging_interval <= dt_data_output_av must hold. If an interval is defined, then by default the average is calculated from the data values of all timesteps lying within this interval. The number of time levels entering into the average can be reduced with the parameter dt_averaging_input. If an averaging interval can not be completed at the end of a run, it will be finished at the beginning of the next restart run. Thus for restart runs, averaging intervals do not necessarily begin at the beginning of the run. Parameters averaging_interval_pr and averaging_interval_sp can be used to define different averaging intervals for vertical profile data and spectra, respectively.
[=#<insert_parameter_name> <insert_parameter_name>]	<insert type>	<insert value>	<insert explanation>