NetCDF data output

PALM is able to output data of different quantities as time series, vertical profiles (usually horizontally averaged), two-dimensional cross sections or 3d-volume data. Depending on the kind of output (time series, profiles, etc.) and the output format (ASCII or binary) data are written to different files (file descriptions can be found here). All data output files are in netCDF format (, which can be processed by many public domain and commercial (graphic) software. Data from netCDF files can also be easily read from Fortran programs provided that a netCDF library is available.

The format of netCDF files generated by PALM is determined by the runtime-parameter netcdf_data_format. The accuracy of the netCDF output data can be set with parameter netcdf_precision. By default, data have single (4 byte) precision.

The following table gives an overview about the different kind of netCDF output data offered by PALM. In addition to the local names of the files, the table also lists the minimum parameter settings which are necessary to switch on the output, as well as the parameters to be used to control the output.

Kind of data Local filename Parameter settings necessary
to switch on output
Further parameters for
output control

vertical profiles


data_output_pr, dt_data_output (or dt_dopr)

averaging_interval, (or averaging_interval_pr), netcdf_data_format, dt_averaging_input, dt_averaging_input_pr, skip_time_data_output (or skip_time_dopr), statistic_regions




netcdf_data_format, statistic_regions



comp_spectra_level, data_output_sp, dt_data_output (or dt_dosp), spectra_direction

averaging_interval (or averaging_interval_sp), netcdf_data_format, dt_averaging_input_pr, skip_time_data_output (or skip_time_dosp)

2d cross section (xy)


data_output (or data_output_user), dt_data_output (or dt_do2d_xy), section_xy

netcdf_data_format, data_output_2d_on_each_pe, do2d_at_begin, skip_time_data_output (or skip_time_do2d_xy)

2d cross section (xy), time-averaged


data_output (or data_output_user), dt_data_output (or dt_data_output_av or dt_do2d_xy), section_xy

averaging_interval, dt_averaging_input, netcdf_data_format, data_output_2d_on_each_pe, do2d_at_begin, skip_time_data_output (or skip_time_data_output_av, or skip_time_do2d_xy)

2d cross section (xz)


data_output (or data_output_user), dt_data_output (or dt_do2d_xz), section_xz

netcdf_data_format, data_output_2d_on_each_pe, do2d_at_begin, skip_time_data_output, (skip_time_do2d_xz

2d cross section (xz), time-averaged


data_output (or data_output_user), dt_data_output (or dt_data_output_av or dt_do2d_xz), section_xz

averaging_interval, dt_averaging_input, netcdf_data_format, data_output_on_each_pe, do2d_at_begin, skip_time_data_output (or skip_time_data_output_av, or doc/app/runtime_parameters)

2d cross section (yz)


data_output, (or data_output_user), dt_data_output (or dt_do2d_yz, section_yz

netcdf_data_format, data_output_2d_on_each_pe, do2d_at_begin, skip_time_data_output (or skip_time_do2d_yz

2d cross section (yz), time-averaged


data_output (or data_output_user), dt_data_output (or dt_data_output_av or dt_do2d_yz), section_yz

averaging_interval, dt_averaging_input, netcdf_data_format, data_output_2d_on_each_pe, do2d_at_begin, skip_time_data_output (or skip_time_data_output_av, or skip_time_do2d_yz, or skip_time_do2d_yz)

3d volume


data_output (or data_output_user), or dt_data_output (or dt_do3d)

netcdf_data_format, do3d_at_begin, nz_do3d, skip_time_data_output (or skip_time_do3d)

3d volume, time-averaged


data_output, (or data_output_user), dt_data_output (or dt_data_output_av or dt_do3d)

averaging_interval, dt_averaging_input, netcdf_data_format, do3d_at_begin, nz_do3d, skip_time_data_output (or skip_time_data_output_av, or skip_time_do3d)

particle timeseries


dt_data_output (or dt_dopts)

particle attributes



agent attributes



dim_size_agtnum_manual, dim_size_factor_agtnum

In addition to the kinds of data mentioned above, it is possible to output quantities at arbitrary locations by using the masked data output.

Last modified 21 months ago Last modified on Feb 27, 2021 11:31:37 AM