DART Python tools

Installation

DART provides a set of Python tools that can be used to work with DART data and models. These tools are located in the DART/pytools directory.

We recommend creating a virtual environment to install DART Python tools. This helps to keep the DART Python tools and their dependencies isolated from other Python packages you may have installed.

python3 -m venv py-dart
source py-dart/bin/activate

You can then install the DART Python tools by navigating to the DART/pytools directory and running:

cd DART/pytools
pip install -r pyDART.txt

When you want to use the DART Python tools in a new session you will need to activate the virtual environment:

source py-dart/bin/activate

To deactivate the virtual environment when you are done, simply run:

deactivate

Available Tool Packages

pyjedi

The pyjedi package provides utilities for DART JEDI interoperability. This is a new package that is under development and is not fully functional yet. At this time, a new converter is available that can transform a JEDI IODA observation file into a DART observation sequence file. This converter can be run as follows:

ioda2obsq <yamlConfigFile> <inputIodaFile> <outputObsqFile>

where <yamlConfigFile> is a YAML configuration file that specifies the mapping between JEDI IODA observation variables and DART observation variables, <inputIodaFile> is the input JEDI IODA observation file, and <outputObsqFile> is the output DART observation sequence file.

The YAML configuration file contains the mapping between JEDI IODA observation variables and DART observation types along with the specification of the desired vertical coordinate variable. Here is an example configuration file for radiosondes:

---

ioda to obsq converter:
  observation variables:
    - name: airTemperature
      type: RADIOSONDE_TEMPERATURE
    - name: specificHumidity
      type: RADIOSONDE_SPECIFIC_HUMIDITY
    - name: windEastward
      type: RADIOSONDE_U_WIND_COMPONENT
    - name: windNorthward
      type: RADIOSONDE_V_WIND_COMPONENT

  vertical coordinate:
    name: MetaData/pressure
    units: "pressure (Pa)"

The name: entries are the names of the variables in the JEDI IODA observation file, and the type: entries are the corresponding DART observation types. The vertical coordinate section specifies the variable that will be used as the vertical coordinate in the DART observation sequence file. Note that in the vertical coordinate section, the name: entry must specify the full netcdf path to the variabile in the JEDI IODA observation file, and the units: entry specifies the units to be used in the DART observation sequence file.

Note

The ioda2obsq tool is under active development and has limited functionality at this time. It is expected that more features will be added soon, including support for satellite radiance observation types. In its current state, it is primarily intended for use with radiosonde and similar conventional observation types.