SH055-01
Parker Solar Probe In-Situ Observations of Magnetic Reconnection in the Near-Sun Solar Wind
Wednesday, 16 December 2020: 16:00
Virtual
Tai Phan1, Stuart D Bale2, Benoit Lavraud3, Jonathan P Eastwood4, Davin E Larson5, Roberto Livi6, Jasper S Halekas7, Phyllis L Whittlesey6, Ali Rahmati2, Marc Pulupa6, Robert J MacDowall8, Michael Louis Stevens9, Anthony W Case9, Justin Christophe Kasper10, Kelly E Korreck9, John W Bonnell11, James Frederick Drake12, Michael A Shay13, Marit Oieroset1, Timothy Simon Horbury14, Marco C M Velli15, Nour E. Raouafi16, Adam Szabo17, Andriy Koval17, Keith Goetz18 and Peter Harvey19, (1)Univ California, Berkeley, CA, United States, (2)University of California Berkeley, Space Sciences Laboratory, Berkeley, CA, United States, (3)IRAP/CNRS, Toulouse, France, (4)Imperial College London, Physics, London, SW7, United Kingdom, (5)Space Sciences Laboratory, Berkeley, CA, United States, (6)Space Sciences Laboratory, University of California Berkeley, Berkeley, CA, United States, (7)University of Iowa, Department of Physics and Astronomy, Iowa City, IA, United States, (8)NASA/Goddard Space Flight Center, Greenbelt, United States, (9)Smithsonian Astrophysical Observatory, Cambridge, MA, United States, (10)University of Michigan, Climate and Space Sciences and Engineering, Ann Arbor, MI, United States, (11)University of California, Berkeley, Space Sciences Laboratory, Berkeley, CA, United States, (12)University of Maryland College Park, College Park, MD, United States, (13)University of Delaware, Newark, DE, United States, (14)Imperial College London, Department of Physics, London, SW7, United Kingdom, (15)University of California Los Angeles, Los Angeles, CA, United States, (16)Johns Hopkins University, Baltimore, MD, United States, (17)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (18)University of Minnesota, School of Physics and Astronomy, Minneapolis, MN, United States, (19)Space Sciences Laboratory, Berkeley, United States
Abstract:
During the first five orbits, PSP has encountered a large number of current sheets in the near-Sun solar wind. Magnetic reconnection exhausts have been detected in current sheets associated with the heliospheric current sheet (HCS), coronal mass ejections, magnetic flux ropes, and the regular solar wind. PSP crossings of the HCS have revealed beautiful examples of both sunward and anti-sunward-directed exhausts. In the sunward exhausts, PSP detected counterstreaming strahl electrons, indicating that HCS reconnection resulted in the formation of closed magnetic field lines with both feet on the Sun. In the anti-sunward exhausts, PSP observed dropouts of strahl electrons, consistent with the reconnected HCS field lines being disconnected from the Sun.
An early surprise was that the majority of solar wind current sheets encountered by PSP near perihelia did not appear to be undergoing local reconnection. Furthermore, reconnection seems to be occurring more commonly in large-scale heliospheric current sheets than in small-scale, thin current sheets, raising questions about what conditions control the onset of reconnection. PSP observations so far have demonstrated that the near-Sun solar wind is a rich laboratory ideal for the investigations of the reconnection onset conditions, as well as the large-scale consequences of reconnection.
