Journal article
Multiple Subscale Magnetic Reconnection Embedded inside a Heliospheric Current Sheet Reconnection Exhaust: Evidence for Flux Rope Merging
Astrophysical journal. Letters, Vol.971(2), L42
08/16/2024
DOI: 10.3847/2041-8213/ad6841
Abstract
We report observations of multiple subscale reconnecting current sheets embedded inside a large-scale heliospheric current sheet (HCS) reconnection exhaust. The discovery was made possible by the unusual skimming trajectory of Parker Solar Probe through a sunward-directed HCS exhaust, sampling structures convecting with the exhaust outflows for more than 3 hr during Encounter 14, at a radial distance of ∼17 solar radii. A large number of subscale current sheets (SCSs) were detected inside the HCS exhaust. Remarkably, five SCSs showed direct evidence for reconnection, displaying near-Alfvénic outflow jets and bifurcated current sheets. The reconnecting SCSs all had small magnetic shears (27°–81°), i.e., strong guide fields. The thickness of the subscale reconnecting current sheets ranged from ∼60 km to ∼5000 km (∼20–2000 ion inertial lengths). The SCS exhausts were directed predominantly in the normal or out-of-plane direction of the HCS, i.e., nearly orthogonal to the HCS exhaust direction. The presence of multiple low-magnetic-shear reconnecting current sheets inside a large-scale exhaust could be associated with coalescence of multiple large flux ropes inside the HCS exhaust. The orientation of some SCS exhausts was partly in the ecliptic plane of the HCS, which may indicate that the coalescence process is highly three-dimensional. Since the coalescence process is likely short-lived, the detection of five such events inside a single HCS crossing could imply the common occurrence of flux rope coalescence in large-scale HCS reconnection exhausts.
Details
- Title: Subtitle
- Multiple Subscale Magnetic Reconnection Embedded inside a Heliospheric Current Sheet Reconnection Exhaust: Evidence for Flux Rope Merging
- Creators
- D. Larson - University of California, BerkeleyM. Oieroset - University of California, BerkeleyS. Eriksson - Laboratory for Atmospheric and Space PhysicsZ. Yin - University of Maryland, College ParkB. Lavraud - Université Fédérale de Toulouse Midi-PyrénéesM. Swisdak - University of Maryland, College ParkS. D. Bale - University of California, BerkeleyR. Livi - University of California, BerkeleyO. Romeo - University of California, BerkeleyP. Whittlesey - University of California, BerkeleyJ. Halekas - University of Iowa , Iowa City, IA, USAA. Rahmati - University of California, BerkeleyM. Pulupa - University of California, BerkeleyA. Szabo - Goddard Space Flight CenterA. Koval - University of Maryland, Baltimore CountyM. Moncuquet - Laboratoire d’études spatiales et d’instrumentation en astrophysiqueJ. Kasper - University of MichiganM. Stevens - Center for Astrophysics Harvard & SmithsonianM. Desai - Southwest Research InstituteT. D. Phan - University of California, BerkeleyN. Raouafi - Johns Hopkins University Applied Physics LaboratoryJ. F. Drake - University of Maryland, College Park
- Resource Type
- Journal article
- Publication Details
- Astrophysical journal. Letters, Vol.971(2), L42
- DOI
- 10.3847/2041-8213/ad6841
- ISSN
- 2041-8205
- eISSN
- 2041-8213
- Publisher
- The American Astronomical Society; BRISTOL
- Number of pages
- 8
- Grant note
- 80NSSC20K1781 / NASA ∣ SMD ∣ Heliophysics Division (HPD) (https://doi.org/10.13039/100020016) NNG04EB99C / NASA ∣ SMD ∣ Heliophysics Division (HPD) (https://doi.org/10.13039/100020016) AGS-2024198 / NSF ∣ GEO ∣ Division of Atmospheric and Geospace Sciences (AGS) (https://doi.org/10.13039/100000159) 80NSSC22K0433 / NASA ∣ SMD ∣ Heliophysics Division (HPD) (https://doi.org/10.13039/100020016) PHY2109083 / NSF ∣ MPS ∣ Division of Physics (PHY) (https://doi.org/10.13039/100000166) NNN06AA01C / NASA ∣ SMD ∣ Heliophysics Division (HPD) (https://doi.org/10.13039/100020016)
- Language
- English
- Date published
- 08/16/2024
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984696864602771
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