PALM input data preparation

PALM Input Data Standard (PIDS)

PALM provides a standardized way to input e.g. global attributes, topography data or surface properties, vegetation properties, etc., as well as initialization data and boundary conditions for the prognostic variables via the netCDF data format. In the following, these files are referred to as so-called drivers.

All available input variables are listed and explained in the following pages and additional remarks on restrictions and initialization are given. Please note, this documentation does not comprise all possible global attributes and variables, only those which are required by PALM. More detailed information on variable attributes can be found in the following linked description of the input files. In the attachments also older versions of the Palm-input-data standard are provided for reference. However, please note, these documents are not maintained any more, all relevant information on the input standard is given in the following linked description of the input files.

Input data is distinguished between static, dynamic, radiation, chemistry, aerosol, and virtual measurements input variables. For each category a separate PIDS driver file can be used:

• The static input file (PIDS_STATIC), contains all static information, such as topography, geographical latitude and longitude, surface and vegetation information. For details, see static driver
  
• The dynamic input file (PIDS_DYNAMIC) , contains dynamic information on the initial state of the atmosphere or time-dependent boundary conditions. For details, see dynamic driver
  
• The radiation input file (PIDS_RAD, contains static and dynamic information on radiation properties such as trace gas profiles or sky-view factors (attenttion: implementation is under way). For details, see radiation driver
  
• The chemistry input file (PIDS_CHEM) contains static and dynamic information on chemical species and emissions. For details, see chemistry driver
  
• The aerosol input file (PIDS_SALSA, after the aerosol module name "SALSA"),contains aerosol emission information. For details, see aerosol driver
  
• The virtual measurement input file (PIDS_VM, comprises metadata to perform on-the-fly virtual measurements. For details, see virtual measurements file
  
• PIDS_UVEM (description coming soon)
• PIDS_WTM (description coming soon)

There are additional drivers if the RRTMG radiation model is used:

• Longwave radiation driver (RRTMG_LW)
• Shortwave radiation driver (RRTMG_SW)

RRTMG is shipped along with standard drivers that contain standard atmospheric properties of pressure, temperature, humidity, greenhouse and trace gases up to the top of the atmosphere which can be copied to the INPUT folder if no other data is available.

Preparation of the static driver

PALM comes with two tools that can help to create the static driver:

1. You can use the python script create_basic_static_driver.py​ as a starting point for creating your own static driver. The script contains an example how to populate the driver with generic topography.

2. The palm_csd​ tool has been developed in the course of ​the MOSAIK project, and allows to create comprehensive static driver files, but relies on pre-processed netCDF data. For the German cities of Berlin and Hamburg, the required data can be provided on request (​maronga@meteo.uni-hannover.de). You can adapt the script for other cities. For a detailed documentation, see palm_csd documentation.

Preparation of the dynamic driver

To create a dynamic driver, PALM provides the pre-processing tool INIFOR, which extracts 1D/3D initialization data for the soil and atmosphere as well as boundary data for the PALM domain from DWD-COSMO output. Alternatively, the tool WRF interface can be used to extract meteorological and chemical initialization and boundary data from WRF and CAMx outputs.

Preparation of the virtual measurements driver

To create a setup file for virtual measurements, you can use the tool palm_cvd​.