Spectra Module Reference#

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Spectra Parameters#

Parameter	Default	Description
averaging_interval_sp	undefined	Averaging interval for spectra output to local file DATA_1D_SP_NETCDF.
comp_spectra_level	undefined	Vertical level for which horizontal spectra are to be calculated and output.
data_output_sp	undefined	Quantities for which horizontal spectra are to be calculated and output.
dt_dosp	undefined	Temporal interval at which spectra shall be output.
skip_time_dosp	undefined	Prohibits spectra data output until this interval has elapsed.
spectra_direction	undefined	Direction(s) along spectra are to be calculated.
switch_off_module	.FALSE.	Switches off the module if set .T.

averaging_interval_sp#

Fortran Type: R

Default: undefined

SI-Unit: s

Averaging interval for spectra output to local file DATA_1D_SP_NETCDF.

If this parameter has a non-zero value, temporally averaged spectra data are output. By default, spectra data are not subject to temporal averaging. The output interval length is limited by the parameter dt_dosp. In all cases, averaging_interval_sp <= dt_dosp must hold.

If an interval is defined, then by default the average is calculated from the data values of all time steps lying within this interval. The number of time steps entering into the average can be reduced with parameter dt_averaging_input_pr. 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.

comp_spectra_level#

Fortran Type: I (100)

Default: undefined

Vertical level for which horizontal spectra are to be calculated and output.

Levels are given as grid index k. Spectra can be calculated for up to 100 vertical levels.

data_output_sp#

Fortran Type: C*10 (10)

Default: undefined

Quantities for which horizontal spectra are to be calculated and output.

This is the general parameter to switch on calculation of spectra. Allowed standard quantities are data_output_sp = 'u', 'v', 'w', 'pt', 'q', 's'. Further quantities may be defined via the user-interface (see [../userint/output further quantities]).

Parameters comp_spectra_level and spectra_direction must be set too! Otherwise, no output will be generated. By default, spectra data are output in NetCDF format to the local file DATA_1D_SP_NETCDF. The temporal interval of the output times of spectra is assigned via the parameter dt_dosp. Spectra can also be temporally averaged (see averaging_interval_sp).

Spectra are calculated using the FFT-method defined by fft_method. Attention: Computation of spectra is currently not possible with fft_method = 'fftw'.

Calculation of spectra requires cyclic boundary conditions along the respective directions (see bc_lr and bc_ns).

dt_dosp#

Fortran Type: R

Default: undefined

SI-Unit: s

Temporal interval at which spectra shall be output.

Output can be skipped at the beginning of a simulation using parameter skip_time_dosp, which has zero value by default. Reference time is the beginning of the simulation, i.e. output takes place at times t = skip_time_dosp + dt_dosp, skip_time_dosp + 2 * dt_dosp, skip_time_dosp + 3 * dt_dosp, etc. The actual output times can slightly deviate from these theoretical values (see dt_dopr). If dt_dosp < dt, then spectra are output after each time step (it is advised to set dt_dosp = 0 if this kind of output is desired).

skip_time_dosp#

Fortran Type: R

Default: undefined

SI-Unit: s

Prohibits spectra data output until this interval has elapsed.

Counting from the beginning of the simulation t = 0 or dt_dosp.

Example:
If dt_dosp = 3600.0 and skip_time_dosp = 1800.0, then the first output will occur at t = 5400 s.

spectra_direction#

Fortran Type: C*2 (10)

Default: undefined

Direction(s) along spectra are to be calculated.

For each quantity given by data_output_sp a corresponding direction must be assigned. E.g., if data_output_sp = 'u', 'w' is set, then spectra_direction = 'x', 'xy', means that spectra along x will be calculated for u and spectra along x and y will be calculated for w. Note that spectra are always averaged perpendicular to their chosen direction, i.e. spectra along x are calculated for each grid line along the x-direction and subsequently averaged along y.

Currently 3 choices are available:

• x

  Spectra are calculated for each grid line along the x-direction and subsequently averaged along y.

• y

  Spectra are calculated for each grid line along the y-direction and subsequently averaged along x.

• xy

  Spectra are calculated along the x- as well as along the y-direction and both spectra are output (no 2d-spectra calculation!).

switch_off_module#

Fortran Type: L

Default: .FALSE.

Switches off the module if set .T.