Masked data output

General

From release 3.7a (r483) output of masked data is implemented in PALM. This feature allows to output quantities at different mask locations, e.g. 3d volume data or 2d cross sections of arbitrary extension within the model domain; 0d or 1d data at any positions and of any amount.
NetCDF4 file format is already available for masked data output.
Default quantities (instantaneous and time averaged) can be declared with the parameter data_output_masks, user-defined quantities can be output with data_output_masks_user.

Output steering

Different runtime parameters defines the masks and steers the output of the quantities assigned with data_output_masks and/or data_output_masks_user:

dt_domask	temporal interval at which instantaneous masked data shall be output (in s)
mask_scale_x	scaling length for masked data output in x-direction
mask_scale_y	scaling length for masked data output in y-direction
mask_scale_z	scaling length for masked data output in z-direction
mask_x	all x-coordinates of mask locations (in m)
mask_y	all y-coordinates of mask locations (in m)
mask_z	all z-coordinates of mask locations (in m)
mask_x_loop	loop begin, end and stride for x-coordinates of mask locations for masks (in multiples of mask scale)
mask_y_loop	loop begin, end and stride for y-coordinates of mask locations for masks (in multiples of mask scale)
mask_z_loop	loop begin, end and stride for z-coordinates of mask locations for masks (in multiples of mask scale)
skip_time_domask	no output of masked data before this interval has passed (in s)

So far 20 different masks can be defined. Each mask is output to one local file:
Instantaneous data of mask 1 are output to file DATA_MASK_01_NETCDF, time-averaged data to file DATA_MASK_01_AV_NETCDF.
Instantaneous data of mask 2 are output to file DATA_MASK_02_NETCDF, time-averaged data to file DATA_MASK_02_AV_NETCDF.
Instantaneous data of mask 3 are output to file DATA_MASK_03_NETCDF, time-averaged data to file DATA_MASK_03_AV_NETCDF.
...
Instantaneous data of mask 20 are output to file DATA_MASK_20_NETCDF, time-averaged data to file DATA_MASK_20_AV_NETCDF.


Besides assigning the parameters listed above, the required output files have to be comment out in the mrun-configuration file?:

#----------------------------------------------------------------------------
# List of output-files
#----------------------------------------------------------------------------
DATA_MASK_01_NETCDF       out:loc      ma#:maf         $output_data      _m01     nc
DATA_MASK_01_AV_NETCDF    out:loc      ma#:maf         $output_data      _m01_av  nc
DATA_MASK_02_NETCDF       out:loc      ma#:maf         $output_data      _m02     nc
DATA_MASK_02_AV_NETCDF    out:loc      ma#:maf         $output_data      _m02_av  nc
#DATA_MASK_03_NETCDF       out:loc      ma#:maf         $output_data      _m03     nc
#DATA_MASK_03_AV_NETCDF    out:loc      ma#:maf         $output_data      _m03_av  nc
...
#DATA_MASK_20_NETCDF       out:loc      ma#:maf         $output_data      _m20     nc
#DATA_MASK_20_AV_NETCDF    out:loc      ma#:maf         $output_data      _m20_av  nc

Here output of masks 1 and 2 is done. Masks 3 to 20 will not be output even if the parameters are assigned.


Within the mrun call ma# has to be added to the mrun-option -r:

mrun -d example_cbl -h... -r "d3# ma#"

Examples

The following examples are given for the example_cbl run with a model domain of 2000m x 2000m x 2000m and a resolution of 50.0m.

Output of one mask

Mask 1: 3d volume data with an extension of 500m x 200m x 2000m from x=0m to x=500m, from y=800m to y=1000m and from the bottom to the top of the model domain of instantaneous data of the wind components

&inipar

    nx = 39, ny = 39, nz = 40,
    dx = 50.0, dy = 50.0, dz = 50.0,
    .../

&d3par

    ...
    data_output_masks (1,:) = 'u','v','w',
   
    mask_x_loop (1,:) = 0., 500. ,50. ,
    mask_y_loop (1,:) = 800., 1000., 50. ,/

If mask_z or mask_z_loop are not assigned, all gridpoints are used along the z-direction.
Output is done at t = dt_data_output? since dt_domask is not assigned.

Output of two different masks

Mask 1: xy cross section from x=500m to x=1000m and from y=1000m to 2000m at heights 0m, 50m, 100m, 500m, 1000m and 1200m of instantaneous and time averaged data of the wind components
Mask 2: every second gridpoint in all directions of the potential temperature

&inipar

    nx = 39, ny = 39, nz = 40,
    dx = 50.0, dy = 50.0, dz = 50.0,
    .../

&d3par

    ...
    data_output_masks (1,:) = 'u','v','w','u_av','v_av','w_av',
    data_output_masks (2,:) = 'pt'
   
    mask_x_loop (1,:) = 500.,1000.,50. ,
    mask_y_loop (1,:) = 1000.,2000.,50. ,
    mask_z (1,:) = 0.,50.,100.,500.,1000.,1200.,

    mask_x_loop (2,:) = 0.,2000.,100.,
    mask_y_loop (2,:) = 0.,2000.,100.,
    mask_z_loop (2,:) = 0.,2000.,100.,/