Recent progress in modeling Farley-Buneman turbulence: Revisiting fluid stability and the application of surrogate models

It is generally accepted that modeling Farley-Buneman instabilities require resolving ion Landau damping to reproduce experimentally observed features. Particle-in-cell (PIC) simulations have been able to reproduce most of these but at a computational cost that severely affects their scalability. This limitation hinders the study of non-local phenomena that require three dimensions or coupling with larger-scale processes. We argue that a form of the five-moment fluid system can recreate several qualitative aspects of Farley–Buneman dynamics, such as density and phase speed saturation, wave turning, and heating. Unexpectedly, these features are reproduced even without using artificial viscosity to capture Landau damping. This work will describe the mechanisms that allow fluid models to capture this instability despite the standard predictions. Our results suggest that the electron inertia, commonly neglected, can contribute significantly to stabilizing the system through the advection term. Furthermore, we will compare the role of thermal effects, viscosity, and Landau closures as stabilizing mechanisms. Moreover, we will briefly describe recent efforts to build surrogate models based on Gaussian processes to capture the main features of these simulations and how these surrogates can be used for plasma diagnostics and multiscale simulations.