Premium
Energetic Proton Acceleration Associated With Io's Footprint Tail
Author(s) -
Clark G.,
Mauk B. H.,
Kollmann P.,
Szalay J. R.,
Sulaiman A. H.,
Gershman D. J.,
Saur J.,
Janser S.,
GarciaSage K.,
Greathouse T.,
Paranicas C.,
Allegrini F.,
Bagenal F.,
Bolton S. J.,
Connerney J. E. P.,
Ebert R. W.,
Hospodarsky G.,
Haggerty D.,
Hue V.,
Imai M.,
Kotsiaros S.,
McComas D. J.,
Rymer A.,
Westlake J.
Publication year - 2020
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2020gl090839
Subject(s) - physics , proton , cyclotron , particle acceleration , magnetosphere , ion , charged particle , acceleration , field line , plasma , atomic physics , computational physics , nuclear physics , classical mechanics , quantum mechanics
Observations of energetic charged particles associated with Io's footprint (IFP) tail, and likely within or very near the Main Alfvén Wing, during Juno's 12th perijove (PJ) crossing show evidence of intense proton acceleration by wave‐particle heating. Measurements made by Juno/JEDI reveal proton characteristics that include pitch angle distributions concentrated along the upward loss cone, broad energy distributions that span ~50 keV to 1 MeV, highly structured temporal/spatial variations in the particle intensities, and energy fluxes as high as ~100 mW/m 2 . Simultaneous measurements of the plasma waves and magnetic field suggest the presence of ion cyclotron waves and transverse Alfvénic fluctuations. We interpret the proton observations as upgoing conics likely accelerated via resonant interactions with ion cyclotron waves. These observations represent the first measurements of ion conics associated with moon‐magnetosphere interactions, suggesting energetic ion acceleration plays a more important role in the IFP tail region than previously considered.