Pyharp: Python-first High-performance Atmosphere Radiation Package

Pyharp is the one-stop tool for calculating the radiation flux of planetary atmospheres, from terrestrial to giant planets. Detailed documentation and examples are available at https://pyharp.readthedocs.io.

Installation

Pyharp can be installed via pip:

pip install pyharp

We support Linux and Mac operation systems with Python version 3.9+.

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Supported opacities

Pyharp has built-in functionalities that work with various opacity sources. The following table summaries off-the-shelf opacities.

Opacity Name	Tested	Peer Reviewed	References
Premix H2 molecule	YES	NO	[1]
H2-He continuum	YES	YES	[2]
CO2 molecule	YES	NO
CO2 continuum	YES	NO
H2O molecule	YES	NO
H2O continuum	YES	NO
N2 molecule	YES	NO
N2 continuum	YES	NO
Grey (user implement)	YES	NO
(More coming)	...	...

Supported radiative transfer solvers

You can choose the backend radiative transfer solver to use by Pyharp. Here are the available options:

Radiative Transfer Solver	Tested	Peer Reviewed	References
DISORT	YES	YES	[1]
Two-steam (Toon-McKay)	NO	NO

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Development

If you want to further develop Pyharp, you will need to install it locally, which allows you to modify the source code and test. Open a Linux or Mac terminal and clone this repo using the following command:

git clone https://github.com/chengcli/pyharp

This will copy all source files into your local computer. You will need to install a few system libraries before installing Pyharp. All following instructions are executed under the pyharp/ directory.

System required for building locally

• Python 3.9+
• Linux or macOS
• netCDF
• python virtual environment (venv)

MacOS installation

brew install netcdf

RedHat installation

sudo yum install netcdf

Ubuntu installation

sudo apt-get install libnetcdf-dev

Build C++ library

After you completed the installation steps, you can build the pyharp library. We will build the package in-place, meaning that the build (binary files) are located under pyharp/build/bin. To do so, make a new directory named build

mkdir build

All build files will be generated and placed under this directory. It is completely safe to delete the whole directory if you want another build. cd to build and cmake

cd build
cmake ..

This command tells the cmake command to look for CMakeFiles.txt in the parent directory, and start configuring the compile environment. Then compile the code by

make -j4

This comman will use 4 cores to compile the code in parallel. Once complete, all executable files will be placed in build/bin.

Build python package locally (dev mode)

The python library can be installed by running the following command in the root directory:

pip install -e .

Test the installation

To test the installation, import pyharp in a python shell:

import pyharp

The build is successful if you do not see any error messages.

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Contributing

Contributions are welcome! Please open an issue or PR if you’d like to:

• Find a bug
• Suggest new functions
• Add examples
• Improve documentation
• Expand test coverage

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Contact

Maintained by @chengcli — feel free to reach out with ideas, feedback, or collaboration proposals.