Investigation of the role of selected collisionless processes in heat flux regulation in the solar wind

• Applicant: Professorin Dr. Maria Elena Innocenti
• Subject Area: Astrophysics and Astronomy ; Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 497938371

Kinetic, collisionless processes control fundamental dynamics in heliospheric plasmas, notwithstanding the extreme separation of scales between system and kinetic scales in the solar wind. Large scale ion and electron properties of the wind are constrained by kinetic instabilities. Observations and simulations, including recent Parker Solar Probe observations few solar radii away from the Sun, show that collisionless processes have a fundamental role in regulating the heliospheric heat flux, which in turn controls the solar wind energy budget and, indirectly, the spatial extension of the heliosphere.Within this project, we will use newly developed numerical methods to contribute to the understanding of collisionless regulation of the heat flux. We will specifically address the role of kinetic processes, such as kinetic instabilities and wave/ particle interaction processes triggered in the presence of large-scale magnetic field fluctuations, in heat flux regulation under different solar wind conditions. We will use our simulations to predict and explain observed Velocity Distribution Functions (VDFs) at different heliocentric distances. We will study the effect on heat flux regulation of solar wind expansion, which alters the evolution of heat flux-regulating instabilities and hence indirectly contributes to heat flux regulation. Our findings will be constantly compared and validated against current and historical observations, chiefly from the Parker Solar Probe and Solar Orbiter missions.

• DFG Programme: Research Grants
• International Connection: United Kingdom
• Cooperation Partner: Dr. Daniel Verscharen