Rotationally driven magnetic reconnection in Saturn's dayside
File(s)manuscript-final version unedited_Gao.pdf (1.37 MB) Supplementary Information_Yao.pdf (1.71 MB)
Accepted version
Supporting information
Author(s)
Type
Journal Article
Abstract
Magnetic reconnection is a key process that explosively accelerates charged particles, generating phenomena such as nebular flares1, solar flares2 and stunning aurorae3. In planetary magnetospheres, magnetic reconnection has often been identified on the dayside magnetopause and in the nightside magnetodisc, where thin-current-sheet conditions are conducive to reconnection4. The dayside magnetodisc is usually considered thicker than the nightside due to the compression of solar wind, and is therefore not an ideal environment for reconnection. In contrast, a recent statistical study of magnetic flux circulation strongly suggests that magnetic reconnection must occur throughout Saturn’s dayside magnetosphere5. Additionally, the source of energetic plasma can be present in the noon sector of giant planetary magnetospheres6. However, so far, dayside magnetic reconnection has only been identified at the magnetopause. Here, we report direct evidence of near-noon reconnection within Saturn’s magnetodisc using measurements from the Cassini spacecraft. The measured energetic electrons and ions (ranging from tens to hundreds of keV) and the estimated energy flux of ~2.6 mW m–2 within the reconnection region are sufficient to power aurorae. We suggest that dayside magnetodisc reconnection can explain bursty phenomena in the dayside magnetospheres of giant planets, which can potentially advance our understanding of quasi-periodic injections of relativistic electrons6 and auroral pulsations7.
Date Issued
2018-08-01
Date Acceptance
2018-04-04
Citation
Nature Astronomy, 2018, 2 (8), pp.640-645
ISSN
2397-3366
Publisher
Nature Publishing Group
Start Page
640
End Page
645
Journal / Book Title
Nature Astronomy
Volume
2
Issue
8
Copyright Statement
© 2018 Springer Nature Limited. The final publication is available at Springer via https://dx.doi.org/10.1038/s41550-018-0461-9
Sponsor
The Royal Society
Science and Technology Facilities Council (STFC)
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000440524400019&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Grant Number
RP140004
ST/P006922/1
Subjects
Science & Technology
Physical Sciences
Astronomy & Astrophysics
JOVIAN MAGNETOTAIL
FIELD
MAGNETOPAUSE
JUPITER
MAGNETOSPHERE
ACCELERATION
INJECTIONS
ELECTRONS
Publication Status
Published
Date Publish Online
2018-06-04