Estimating the possible ion heating caused by Alfvén waves at Venus Show others and affiliations
2024 (English) In: Journal of Geophysical Research - Space Physics, ISSN 2169-9380, E-ISSN 2169-9402, Vol. 129, no 12, article id e2024JA032865Article in journal (Refereed) Published
Abstract [en]
In the Earth's magnetosphere wave-particle interaction is a major ion energization process, playing an important role for the atmospheric escape. A common type of ion heating is associated with low-frequency broadband electric wave fields. For such waves the energy is not concentrated to a certain narrow frequency range and exhibits no peaks or dips in a power spectrum. If there are enough fluctuations close to the ion gyrofrequency the electric field may still come in resonance with gyrating ions and heat them perpendicular to the background magnetic field. We perform a proof-of-concept study to investigate if this heating mechanism may contibute significantly to the energization of planetary ions also in the induced magnetosphere of Venus. We assume Alfvénic fluctuations and estimate the electric field spectral density based on magnetic field observations. We find typical estimated electric spectral densities of a few (Formula presented.) /Hz close to Venus. This corresponds to a heating rate of a few eV/s. We consider an available interaction time of (Formula presented.) 300 s and conclude that this mechanism could increase the energy of an oxygen ion by about a keV. Observed thermal energies are in the range 100–1,000 eV and thus, resonant wave heating may also be important at Venus.
Place, publisher, year, edition, pages American Geophysical Union (AGU), 2024. Vol. 129, no 12, article id e2024JA032865
Keywords [en]
ion energization, resonant heating, Venus, wave-particle interaction
National Category
Fusion, Plasma and Space Physics Geophysics
Identifiers URN: urn:nbn:se:umu:diva-233330 DOI: 10.1029/2024JA032865 ISI: 001372415600001 Scopus ID: 2-s2.0-85211761537 OAI: oai:DiVA.org:umu-233330 DiVA, id: diva2:1924036
Funder Swedish Institute, 79/19 Swedish National Space Board 2025-01-022025-01-022025-01-02 Bibliographically approved