Surface output parameters














Information about surface properties as well as the actual physical conditions at horizontal and vertical surfaces can be output in NetCDF format (parallel NetCDF4 installation required) or in binary format. The binary output can be further processed and visualized with Paraview via VTK-files which allows the input of unstructured data. Output is written into binary files SURFACE_DATA_BIN and SURFACE_DATA_AV_BIN, respectively. Please note, in order to visualize surface data with Paraview, the PALM output data needs to be further converted into the VTK file format in the post-processing. A suitable post-processing tool is provided under /trunk/UTIL/surface_output_processing/surface_output_to_vtk.f90. This tool comes with an additional namelist file surface_output_parin, where output specific information such as cycle number, path to the output data, etc. needs to be defined.

To enable model output for unstructured surface data the following namelist is required in your PALM parameter file:

NAMELIST group name: surface_data_output_parameters


Parameter Name FORTRAN
Type
Default
Value
Explanation

averaging_interval_surf

R

value of averaging_interval

Averaging interval for surface output data (in s). In any case, averaging_interval_surf <= dt_dosurf_av 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.

data_output_surf

C * 300 (100)

' '

Quantities for which surface data shall be be output. PALM allows the output of instantaneous data as well as of temporally averaged data which is steered by the string '_av' assigned to this parameter (see data_output for more explanation). For example, data_output_surf = 'shf', 'shf_av', will output instantaneous as well as time-averaged data of surface sensible heat flux at all surface elements.

Surface data for all surfaces elements on the processor subdomain is output in a separate NetCDF file. Further, additional information about polygons and vertices defining the surface elements are output. This information enables to create VTK files with a post-processor (not available yet) which can be read by this visualization software PARAVIEW.

The following quantities are available for output:

Quantity name Meaning Unit
us friction velocity m / s
ts scaling parameter for temperature K
qs scaling parameter for mixing ratio kg / kg
ss scaling parameter for passive scalar -
qcs scaling parameter for cloud water mixing ratio kg / kg
ncs scaling parameter for number concentration of cloud water 1 / m3
qrs scaling parameter for rain water mixing ratio kg / kg
nrs scaling parameter for rain water droplet concentration 1 / m3
ol Obukhov length m
z0 roughness length for momentum m
z0h roughness length for heat m
z0q roughness length for moisture m
theta1 potential temperature at 1st grid point outside the wall K
qv1 mixing ratio at 1st grid point outside the wall kg / kg
thetav1 virtual potential temperature at 1st grid point outside the wall K
usws surface momentum flux for the u-component m m / ( s s )
vsws surface momentum flux for the v-component m m / ( s s )
shf surface sensible heat flux K m / s
qsws surface latent heat flux kg m / ( kg s )
ssws surface passive scalar flux m / s
qcsws surface flux of cloud water mixing ratio m kg / ( s kg )
ncsws surface flux of number concentration of cloud water 1 / ( s m2 )
qrsws surface flux of rain water mixing ratio m kg / ( s kg )
nrsws surface flux of rain water droplet concentration 1 / ( s m2 )
sasws surface salinity flux -
q_surface surface moisture kg / kg
theta_surface surface temperature K
thetav_surface surface virtual temperature K
rad_net radiation balance W / m2
rad_lw_in total incoming longwave radiation W / m2
rad_lw_dif incoming longwave radiation flux from sky W / m2
rad_lw_out outgoing longwave radiation flux W / m2
rad_lw_ref incoming longwave radiation flux from reflections W / m2
rad_lw_res residual longwave radiation flux in surfaces after last reflection step W / m2
rad_sw_in total incoming shortwave radiation flux W / m2
rad_sw_dif incoming diffused shortwave radiation flux W / m2
rad_sw_dir direct incoming shortwave radiation flux W / m2
rad_sw_out outgoing shortwave radiation flux W / m2
rad_sw_ref incoming shortwave radiation flux from reflections W / m2
rad_sw_res residual shortwave radiation flux in surfaces after last reflection step W / m2
ghf ground heat flux W / m2
r_a aerodynamic resistance 1 / m
r_soil soil resistance 1 / m
r_canopy canopy resistance 1 / m
r_s total resistance 1 / m
uvw1 surface-parallel flow speed at 1st grid point outside the wall m / s
waste_heat waste_heat, only if indoor_model is applied W / m2
im_hf heatflux at innermost building wall, only if indoor_model is applied W / m2
albedo aggregated albedo value for the surface based on the tile albedo values -
emissivity aggregated emissivity value for the surface based on the tile emissivity values -

dt_dosurf

R

value of dt_data_output

Temporal interval at which instantaneous surface data shall be output (in s). Output can be skipped at the beginning of a simulation using parameter skip_time_dosurf, which has zero value by default.

dt_dosurf_av

R

value of dt_dosurf

Temporal interval at which time averaged surface data shall be output (in s). Output can be skipped at the beginning of a simulation using parameter skip_time_dosurf_av, which has zero value by default.

skip_time_dosurf

R

0.0

No surface data output before this interval has passed (in s). This parameter causes that surface data output activities are starting not before this interval (counting from the beginning of the simulation, t=0) has passed.

skip_time_dosurf_av

R

0.0

No surfave data output of averaged variables before this interval has passed (in s). This parameter causes that averaged surface data output activities are starting not before this interval (counting from the beginning of the simulation, t=0) has passed.

switch_off_module

L

.F.

to_netcdf

L

.F.

Control parameter enabling surface data output to NetCDF. Note, surface data output to NetCDF is only allowed with netcdf_data_format >= 5.

to_vtk

L

.F.

Control parameter enabling surface data output to VTK format.

Last modified 3 years ago Last modified on Feb 26, 2021 3:26:48 PM