Wuppertal 2015 – wissenschaftliches Programm

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EP: Fachverband Extraterrestrische Physik

EP 7: Sonne und Heliosphäre

EP 7.7: Vortrag

Donnerstag, 12. März 2015, 10:00–10:15, G.10.02 (HS 9)

Dissipation Model for Solar Wind Turbulence by Kinetic Alfvén Waves at Electron Scales — •Anne Schreiner and Joachim Saur — Universität zu Köln, Köln, Deutschland

Similar to fluids and gases on Earth, magnetic fluctuations in the solar wind develop characteristic turbulent features. In contrast to hydrodynamic fluids, the solar wind is not dominated by direct collisions. Hence, particle collisions can not be responsible for dissipation of turbulent energy and particle heating. To reveal the physical mechanisms of the dissipation process in solar wind turbulence, we develop a model that describes magnetic energy spectra at the electron scales. Our model combines the energy transport process from large to small scales and collisionless damping processes, which extract energy from the magnetic fluctuations in the kinetic regime. We assume wave-particle interactions to be the main damping process and focus on the role of kinetic Alfvén waves. Therefore, we include the imaginary part of the kinetic Alfvén wave frequency as a damping rate. We find that damping by kinetic Alfvén waves can explain the observed quasi-exponential shape of magnetic spectra in the dissipation range. Our dissipation model provides the possibility to investigate the influence of different damping rate processes and varying solar wind parameters on the dissipation range.