Temperature anisotropy instabilities stimulated by the solar wind suprathermal populations
- This review paper compiles recent results obtained by the present group of authors describing the effects of suprathermal populations present in space plasmas (up to a few keVs) on temperature anisotropy instabilities. Of particular interest are the electromagnetic cyclotron and firehose excitations, which play a major role in limiting temperature anisotropy, resulting, for instance, from the adiabatic expansion of the solar wind. Relying on a rigorous modeling and interpretation of the observed velocity distributions, both theoretical models and numerical simulations indicate a systematic stimulation of these excitations in the presence of suprathermal populations of electrons or protons. Moreover, the enhanced fluctuations react back on particles, and determine a faster and deeper relaxation of their anisotropy. The present comparative analysis suggests that previous studies, considering only quasi-thermal low-energy populations, may have significantly underestimated these excitations and their implications in various applications in space plasmas.
| Author: | Marian LazarORCiDGND, Rodrigo LópezGND, Shaaban Mohammed ShaabanGND, Stefaan PoedtsGND, Peter Haesung YoonGND, Horst FichtnerORCiDGND |
|---|---|
| URN: | urn:nbn:de:hbz:294-86797 |
| DOI: | https://doi.org/10.3389/fspas.2021.777559 |
| Parent Title (English): | Frontiers in astronomy and space sciences |
| Publisher: | Frontiers Media |
| Place of publication: | Lausanne |
| Document Type: | Article |
| Language: | English |
| Date of Publication (online): | 2022/03/04 |
| Date of first Publication: | 2022/01/19 |
| Publishing Institution: | Ruhr-Universität Bochum, Universitätsbibliothek |
| Tag: | instabilities; particle velocity distribution; solar wind; suprathermal particles; temperature |
| Volume: | 8 |
| Issue: | Article 777559 |
| First Page: | 777559-1 |
| Last Page: | 777559-12 |
| Institutes/Facilities: | Institut für Theoretische Physik IV |
| Dewey Decimal Classification: | Naturwissenschaften und Mathematik / Physik |
| open_access (DINI-Set): | open_access |
| faculties: | Fakultät für Physik und Astronomie |
| Licence (English): |  Creative Commons - CC BY 4.0 - Attribution 4.0 International |
