Jovian High‐Latitude Ionospheric Ions: Juno In Situ Observations

P. Valek (1) , F. Allegrini (1, 2) , F. Bagenal (3) , S. Bolton (1) , J. Connerney (4, 5) , R. Ebert (1, 2) , T. Kim (1, 2) , S. Levin (6) , P. Louarn (7) , D. Mccomas (8) , J. Szalay (8) , M. Thomsen , R. Wilson (9)

1 SwRI - Southwest Research Institute [San Antonio]
2 UTSA - The University of Texas at San Antonio
3 LASP - Laboratory for Atmospheric and Space Physics [Boulder]
4 GSFC - NASA Goddard Space Flight Center
5 SSRC - Space Systems Research Corporation
6 JPL - Jet Propulsion Laboratory
7 IRAP - Institut de recherche en astrophysique et planétologie
8 Princeton University
9 University of Colorado [Boulder]

The lowaltitude, highvelocity trajectory of the Juno spacecraft enables the Jovian Auroral Distributions Experiment to make the rst in situ observations of the highlatitude ionospheric plasma. Ions are observed to energies below 1 eV. The highlatitude ionospheric ions are observed simultaneously with a loss cone in the magnetospheric ions, suggesting precipitating magnetospheric ions contribute to the heating of the upper ionosphere, raising the scale height, and pushing ionospheric ions to altitudes of 0.5 RJ above the planet where they are observed by Jovian Auroral Distributions Experiment. The source of the magnetospheric ions is tied to the Io torus and plasma sheet, indicated by the cutoff seen in both the magnetospheric and ionospheric plasma at the Io Mshells. Equatorward of the Io Mshell boundary, the ionospheric ions are not observed, indicating a drop in the scale height of the ionospheric ions at those latitudes.

Domaines: Planète et Univers [physics]

P. Valek, F. Allegrini, F. Bagenal, S. Bolton, J. Connerney, et al.. Jovian High‐Latitude Ionospheric Ions: Juno In Situ Observations. Geophysical Research Letters, 2019, 46 (15), pp.8663-8670. ⟨10.1029/2019GL084146⟩. ⟨hal-02367844⟩