Code for 'Conversion and Damping of Nonaxisymmetric Internal Gravity Waves in Magnetized Stellar Cores'

Cy S. David, Daniel Lecoanet, and Pascale Garaud

Overview

The code in this repository supports the main results in our paper on conversion and damping of nonaxisymmetric internal gravity waves in magnetized stellar cores [1] (doi:10.3847/1538-4357/ae4d18). The folder IVP/ contains Python scripts used to numerically solve the initial value problems (IVPs) in [1] using the Dedalus pseudo-spectral framework [2]. The folder EVP/ contains Python scripts used to construct the Wentzel-Kramers-Brillouin (WKB) solution in [1] and compare it to the simulation results. Finally, the Mathematica notebook "phase-mixing-toy.nb" generates the phase mixing figure and animation (Figure 3) in our manuscript.

Steps to reproduce the figures and animations in [1]:

Run simulations and plot

1. Run IVP I ("sim28"), IVP II ("sim32"), and IVP III ("sim27"):
From IVP/, run

python IVP_I.py
python IVP_II.py
python IVP_III.py

The scripts may be run with parallelization as, e.g.,

mpirun -np 96 python IVP_I.py
mpirun -np 192 python IVP_II.py
mpirun -np 96 python IVP_III.py

2. Generate frames for the animated versions of Figure 2 and Figure 4:
From IVP/, run

python plot_sincos.py sim28
python plot_sincos.py sim32

3. Export snapshots from the last timestep and one-dimensional (1D) timeseries data:
From IVP/, run

python export.py sim28
python export_timeseries.py sim28
python export.py sim32
python export_timeseries.py sim32
python export.py sim27
python export_timeseries.py sim27

4. Generate the static versions of Figure 2 and Figure 4 using IVP/plot_ivp.ipynb

Solve phase mixing toy problem

5. Generate the animated and static versions of Figure 3 using the Mathematica notebook phase-mixing-toy.nb.

Solve eigenvalue problems and construct WKB solution

6. Find WKB wavenumbers and eigenfunctions for both the axisymmetric and nonaxisymmetric problems:
From EVP/, run

python run_eigen_solves.py

7. Construct the WKB solution and it compare to IVP III. Generate Figures 5, 6, 7, 8 using EVP/construct_wkb.ipynb.

8. Generate frames for the supplementary animation ("supplementary.mp4") available on the Zenodo repository:
From IVP/, run

python plot_cg.py sim27

Available data

The main static figures may be generated with Steps 4-7 without completing Steps 1-3, using the snapshots and 1D timeseries available on our Zenodo repository at doi:10.5281/zenodo.18357092 in the compressed folder data.zip. The unzipped folder data should be placed in the directory IVP/. To download the data using the command line, run the following from IVP/:

wget -L -O data.zip "https://zenodo.org/records/18357093/files/data.zip"
unzip data.zip
rm data.zip

Then, follow Steps 4-7.

References

[1]: C.S. David, D. Lecoanet, and P. Garaud. 2026. Conversion and Damping of Nonaxisymmetric Internal Gravity Waves in Magnetized Stellar Cores. ApJ, 1000, 292. doi:10.3847/1538-4357/ae4d18
[2]: Burns, K. J., Vasil, G. M., Oishi, J. S., Lecoanet, D., and Brown, B. P. 2020. Dedalus: A flexible framework for numerical simulations with spectral methods. Phys. Rev. Res., 2, 023068. doi:10.1103/PhysRevResearch.2.023068