Orateur
Description
Co-authors: C. Skene, S. Tobias
Abstract: Many low-mass stars like the Sun host periodic, oscillatory magnetic fields that lead to variable levels of stellar activity and variations of space weather, affecting habitability and detection of exoplanets. Due to the intrinsic difficulties of modelling stellar magnetohydrodynamics at all scales, realistic numerical simulations of this process are very challenging and their reduced-order models of oscillatory dynamos are of interest. In this work, we develop a framework to recover such models directly from numerical data using a combination of Hankel Dynamic Mode Decomposition (DMD) to identify magnetic structures, and Sparse Identification of Nonlinear Dynamics (SINDy) to model their dynamics, and compare it to classic mathematical method of weakly nonlinear analysis (WNL). We implement this approach on a one-dimensional idealized mean-field dynamo model parametrizing the main components of convective dynamo in a low-mass star, helical convection and differential rotation.