Parker Solar Probe Observations of Suprathermal Electron Flux Enhancements Originating from Coronal Hole Boundaries
| Autor: | Allan R. Macneil, Laura Bercic, Mathew J. Owens, Adam J. Finley |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Physics
010504 meteorology & atmospheric sciences FOS: Physical sciences Flux Coronal hole Astronomy and Astrophysics Magnetic reconnection Plasma Electron 01 natural sciences Space Physics (physics.space-ph) Magnetic flux Computational physics Solar wind Astrophysics - Solar and Stellar Astrophysics Physics - Space Physics 13. Climate action Space and Planetary Science 0103 physical sciences Physics::Space Physics Astrophysics::Solar and Stellar Astrophysics 010303 astronomy & astrophysics Event (particle physics) Solar and Stellar Astrophysics (astro-ph.SR) 0105 earth and related environmental sciences |
| ISSN: | 0035-8711 |
| Popis: | Reconnection between pairs of solar magnetic flux elements, one open and the other a closed loop, is theorized to be a crucial process for both maintaining the structure of the corona and producing the solar wind. This ‘interchange reconnection’ is expected to be particularly active at the open-closed boundaries of coronal holes (CHs). Previous analysis of solar wind data at 1 au indicated that peaks in the flux of suprathermal electrons at slow–fast stream interfaces may arise from magnetic connection to the CH boundary, rather than dynamic effects such as compression. Further, offsets between the peak and stream interface locations are suggested to be the result of interchange reconnection at the source. As a preliminary test of these suggestions, we analyse two solar wind streams observed during the first Parker Solar Probe (PSP) perihelion encounter, each associated with equatorial CH boundaries (one leading and one trailing with respect to rotation). Each stream features a peak in suprathermal electron flux, the locations and associated plasma properties of which are indicative of a solar origin, in agreement with previous suggestions from 1 au observations. Discrepancies between locations of the flux peaks and other features suggest that these peaks may too be shifted by source region interchange reconnection. Our interpretation of each event is compatible with a global pattern of open flux transport, although random footpoint motions or other explanations remain feasible. These exploratory results highlight future opportunities for statistical studies regarding interchange reconnection and flux transport at CH boundaries with modern near-Sun missions. |
| Databáze: | OpenAIRE |
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