2003/12/15 by J. Martin Laming · 1 citation
Physics and Astronomy · #Dust and Plasma Wave Phenomena #Ionosphere and magnetosphere dynamics #Solar and Space Plasma Dynamics #astro-ph
paper · pdf · doi:10.1086/382066
published as Astrophys.J. 604 (2004) 874-883 · 32 pages including 11 figures, 4 tables, accepted by ApJ
arxiv created 2003/12/15 · openalex publication_date 2004/03/26 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
We explore a mechanism, entirely new to the fast solar wind, of electron heating by lower hybrid waves to explain the shift to higher charge states observed in various elements in the fast wind at 1 AU relative to the original coronal hole plasma. This process is a variation on that previously discussed for two-temperature accretion flows by Begelman & Chiueh. Lower hybrid waves are generated by gyrating minor ions (mainly α-particles) and become significant once strong ion cyclotron heating sets in beyond 1.5 R ☉ . In this way the model avoids conflict with SUMER electron temperature diagnostic measurements between 1 and 1.5 R ☉ . The principal requirement for such a process to work is the existence of density gradients in the fast solar wind, with scale length of similar order to the proton inertial length. Similar size structures have previously been inferred by other authors from radio scintillation observations and considerations of ion cyclotron wave generation by global resonant MHD waves.