Atmospheres & Climate

Approximating Rayleigh Scattering in Exoplanetary Atmospheres using Physics-informed Neural Networks (PINNs)

By Keith Cowing
Press Release
August 11, 2024
Filed under , , , ,
Approximating Rayleigh Scattering in Exoplanetary Atmospheres using Physics-informed Neural Networks (PINNs)
Example solution for the 𝛼(π‘₯, 𝑦) shown in Fig. 1 for the direction of the light in positive x-direction (πœ™ = 0). Top: The complete solution (left), the solution if scattering would be treated as absorption (middle) and the difference between the two: the scattered light component (right), all in units of 𝑒0 := 𝑒(π‘₯ = βˆ’1, πœ™ = 0) = 1. Bottom: The logarithm (log10) of the respective residuals of the differential equations. The middle plot shows the residual of π‘’π‘Ž with respect to the RTE without scattering and the right one the residual of (π‘’π‘Ž + 𝑒𝑠 ) with respect to the complete RTE. The left plot is calculated from the two residuals by taking their root mean square. — astro-ph.EP

This research introduces an innovative application of physics-informed neural networks (PINNs) to tackle the intricate challenges of radiative transfer (RT) modeling in exoplanetary atmospheres, with a special focus on efficiently handling scattering phenomena.

Traditional RT models often simplify scattering as absorption, leading to inaccuracies. Our approach utilizes PINNs, noted for their ability to incorporate the governing differential equations of RT directly into their loss function, thus offering a more precise yet potentially fast modeling technique. The core of our method involves the development of a parameterized PINN tailored for a modified RT equation, enhancing its adaptability to various atmospheric scenarios.

We focus on RT in transiting exoplanet atmospheres using a simplified 1D isothermal model with pressure-dependent coefficients for absorption and Rayleigh scattering. In scenarios of pure absorption, the PINN demonstrates its effectiveness in predicting transmission spectra for diverse absorption profiles.

For Rayleigh scattering, the network successfully computes the RT equation, addressing both direct and diffuse stellar light components. While our preliminary results with simplified models are promising, indicating the potential of PINNs in improving RT calculations, we acknowledge the errors stemming from our approximations as well as the challenges in applying this technique to more complex atmospheric conditions.

Specifically, extending our approach to atmospheres with intricate temperature-pressure profiles and varying scattering properties, such as those introduced by clouds and hazes, remains a significant area for future development.

David DahlbΓΌdding, Karan Molaverdikhani, Barbara Ercolano, Tommaso Grassi

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM); Machine Learning (cs.LG); Neural and Evolutionary Computing (cs.NE)
Cite as: arXiv:2408.00084 [astro-ph.EP] (or arXiv:2408.00084v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2408.00084
Focus to learn more
Submission history
From: David DahlbΓΌdding
[v1] Wed, 31 Jul 2024 18:00:55 UTC (1,867 KB)
https://arxiv.org/abs/2408.00084

Astrobiology, Astronomy,

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) πŸ––πŸ»