PALM Create Static Driver (palm_csd)

In order to create comprehensive drivers for PALM runs in urban environments, PALM comes shipped with the tool palm_csd. This python3-based script was developed in the course of ​the MOSAIK project and thus is, in principal, only working for the democities Berlin, Hamburg, and Stuttgart. However, with some effort it is possible to adapt the script for other cities as well. Note that in the mid-term, palm_csd will be replaced by a more generic and universal tool based with a graphical user interface as front end.

Execution

In order to create a static driver, go to the working directory (usually ~/palm/current_version), prepare a palm_csd configuration file (see below, an exemplary file can be found here​). After set-up of the configuration file, execute palm_csd as follows:

palm_csd .csd.config.default

The static driver will be written to the directory specified in the configuration file. During compilation of the driver, palm_csd will print some more or less useful information to screen.

Configuration file

This section describes how to set-up a configuration file for creating a static driver for PALM based on pre-processed NetCDF data. In the following we will use data for Berlin, which is available via Open Access. The configuration file uses the well-known format of INI files, which are processed by the ConfigParser? package in python. It consists of the following sections:

[global]

A set of global attributes can be defined that will be passed to the static driver file. In details, the following attributes can be set (see also static driver description:

Attribute	Data type	Description
author	string	Author of the static driver. Use the format: name, email
contact	string	Contact person, format as for author
acronym	string	Institional acronym (formating rules applies to static drivers used in the ​MOSAIK project)
comment	string	Arbitrary text
data_content	string	Arbitrary text
dependencies	string	Arbitrary text
keywords	string	Arbitrary keywords
source	string	List of data sources used to generate the driver
campaign	string	Information on measurement capaign (if applicable)
location	string	Geo-location of the static driver content (if applicable)
site	string	Site description od the static driver content (if applicable)
institution	string	Institution of the driver creator
palm_version	float	PALM version for which the driver was generated (for comptatibility checks)
rotation_angle	float	Clockwise angle of rotation in degrees between North positive y axis and the y axis in the data, e.g. 0.0. This value overwrites the namelist parameter rotation_angle
references	string	Arbitrary text

Example:

author = Bjoern Maronga, maronga@muk.uni-hannover.de
contact_person = Bjoern Maronga, maronga@muk.uni-hannover.de
acronym = LUHimuk
comment = created with palm_csd
data_content
dependencies
keywords
source
campaign
location = Berlin
site = Berlin Mitte
institution = Institute of Meteorology and Climatology, Leibniz University Hannover
palm_version = 6.0
rotation_angle = 0.0
references

Note that most of the global attributes have no effect on the PALM simulations, except rotation_angle and palm_version.

[settings]

This section describes global parameters used to create the static driver. All following parameters are mandatory!

Variable	Data type	Description
bridge_width	float	In case that the simulation domain contains bridges, this parameter (in m) defines the vertical thickness of all bridge elements in the domain. Note that bridges require LOD2 building information (i.e. buildings_3d)
debug_mode	logical	Can be set to True or False. Used for debugging by model developers only, currently this parameter has no effect
lai_roof_extensive	float	Leaf are index for green roofs with extensive vegetation, defined by setting the appropriate building_pars field. The value is assigned to all extensive green roofs in the model domain
lai_roof_intensive	float	Leaf are index for green roofs with intensive vegetation, defined by setting the appropriate building_pars field. The value is assigned to all intensive green roofs in the model domain
lai_high_vegetation_default	float	Default leaf area index for (high) vegetation used to generate the 3D leaf area density field. This value is used for all pixels for which no other leaf area density is available (i.e. to fill missing data)
lai_low_vegetation_default	float	Default leaf area index for (low) vegetation used to fill data gaps in the leaf area index distribution. This parameter only will a LOD2 leaf area index for parameterized vegetation via vegetation_type, i.e., through the vegetation_pars field
lai_alpha	float	Parameter for reconstruction of vertical LAD profiles based on tree shape parameters (alpha, beta) and the integral leaf area index after Markkanen et al. (2003). This scheme is used for vegetation patches (parks, forests), where the canopy can be considered to be pseudo-1D and for which usually no information on individual trees is available.
lai_beta	float	Parameter for reconstruction of vertical LAD profiles based on tree shape parameters (alpha, beta) and the integral leaf area index after Markkanen et al. (2003). This scheme is used for vegetation patches (parks, forests), where the canopy can be considered to be pseudo-1D and for which usually no information on individual trees is available.
patch_height_default	float	Default patch height (in m), which is used in the canopy generator to process canopy patches (parks, forests) for which data for individual trees is usually lacking. This parameter comes into affect for data gaps where no other vegetation height is available
season	string	As palm_csd can work with different sets of input data regarding leaf area index, this switch parameter can be set to either "summer" or "winter" to select the most suitable leaf area index input file to account for differences in leaf amount. Data for summer is usually from August (fully leaved), while data for winter is usually from April.

Example:

bridge_width = 3.0
debug_mode = False
lai_roof_extensive = 3.0
lai_roof_intensive = 1.5
lai_high_vegetation_default = 5.0
lai_low_vegetation_default = 1.0
lai_alpha = 5.0
lai_beta = 3.0
patch_height_default = 10.0
season = "summer"

[output]

Variable	Data type	Description
path	string	Directory where the output file shall be stored. Note that the static driver can - depending on model domain size - be quite large (in the order of several GB).
file_out	string	Output file name. The final output will be stored under path/file_out_domain, where domain will be "root" for the parent (root) domain, and "N01", "N02", etc., for child domains N01, N02, etc., respectively
version	integer	User-specific setting to track updates of a static driver. This value will be added as global attribute to the static driver

Example:

path = /ldata2/MOSAIK/
file_out = winter_iop1_test
version = 1

[input_01] - [input_XX]

path = /ldata2/MOSAIK/Berlin_static_driver_data pixel_size = 15.0 file_x = Berlin_CoordinatesUTM_x_15m_DLR.nc file_y = Berlin_CoordinatesUTM_y_15m_DLR.nc file_x_UTM = Berlin_CoordinatesUTM_y_15m_DLR.nc file_y_UTM = Berlin_CoordinatesUTM_x_15m_DLR.nc file_lat = Berlin_CoordinatesLatLon_y_15m_DLR.nc file_lon = Berlin_CoordinatesLatLon_x_15m_DLR.nc file_zt = Berlin_terrain_height_15m_DLR.nc file_buildings_2d = Berlin_building_height_15m_DLR.nc file_building_id = Berlin_building_id_15m_DLR.nc file_building_type = Berlin_building_type_15m_DLR.nc file_bridges_2d = Berlin_bridges_height_15m_DLR.nc file_bridges_id = Berlin_bridges_id_15m_DLR.nc file_lai = Berlin_leaf_area_index_15m_DLR_WANG_summer.nc file_vegetation_type = Berlin_vegetation_type_15m_DLR.nc file_vegetation_height = Berlin_vegetation_patch_height_15m_DLR.nc file_pavement_type = Berlin_pavement_type_15m_DLR.nc file_water_type = Berlin_water_type_15m_DLR.nc file_soil_type = Berlin_soil_type_15m_DLR.nc file_street_type = Berlin_street_type_15m_DLR.nc file_street_crossings = Berlin_street_crossings_15m_DLR.nc file_tree_height = Berlin_trees_height_clean_15m.nc file_tree_crown_diameter = Berlin_tree_crown_15m_DLR.nc file_tree_trunk_diameter = Berlin_trees_trunk_clean_15m.nc file_tree_type = Berlin_trees_type_15m_DLR.nc file_patch_height = Berlin_vegetation_patch_height_15m_DLR.nc file_vegetation_on_roofs = Berlin_vegetation_on_roofs_15m_DLR.nc

[domain_root]

pixel_size = 15.0 origin_x = 19605 origin_y = 20895 nx = 200 ny = 200 buildings_3d = False dz = 15.0 allow_high_vegetation = True generate_vegetation_patches = True use_palm_z_axis= False interpolate_terrain = False domain_parent vegetation_on_roofs = True street_trees = True canopy_patches = True

[domain_01] - [domain_NXX]

pixel_size = 1.0 origin_x = 19605 origin_y = 20895 nx = 1023 ny = 1023 buildings_3d = True dz = 1.0 allow_high_vegetation = False generate_vegetation_patches = True use_palm_z_axis= True interpolate_terrain = True domain_parent = root vegetation_on_roofs = True street_trees = True canopy_patches = True

Canopy generator

Single trees

Vegetation canopies

Required input data

Best practices

Literature

• Heldens et al.
• Mikhailovic & Lalic
• Markkanen, T., Rannik, Ü., Marcolla, B. et al. Footprints and Fetches for Fluxes over Forest Canopies with Varying Structure and Density. Boundary-Layer Meteorology 106, 437–459 (2003). ​https://doi.org/10.1023/A:1021261606719