[en] Integrating simultaneous in-situ measurements of magnetic field fluctuations, precipitating electrons, and ultraviolet auroral emissions, we find that Alfvénic acceleration mechanisms are responsible for Ganymede's auroral footprint tail. Magnetic field perturbations exhibit enhanced Alfvénic activity with Poynting fluxes of 100 mW/m2. These perturbations are capable of accelerating the observed broadband electrons with precipitating fluxes of 11 mW/m2, such that Alfvénic power is transferred to electron acceleration with 10 efficiency. The UV emissions are consistent with in-situ electron measurements, indicating 13 ± 3 mW/m2 of precipitating electron flux. Juno crosses flux tubes with both upward and downward currents connected to the auroral tail exhibiting small-scale structure. We identify an upward electron conic in the downward current region, possibly due to acceleration by inertial Alfvén waves near the Jovian ionosphere. In concert with in-situ observations at Io's footprint tail, these results suggest that Alfvénic acceleration processes are universally applicable to magnetosphere-satellite interactions.
Research Center/Unit :
STAR - Space sciences, Technologies and Astrophysics Research - ULiège
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Szalay, Jamey R.
Allegrini, Frederic
Bagenal, Fran
Bolton, Scott J.
Bonfond, Bertrand ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)
Allegrini, F., Bagenal, F., Bolton, S., Connerney, J., Clark, G., Ebert, R. W., Kim, T. K., Kurth, W. S., Levin, S., Louarn, P., Mauk, B., McComas, D. J., Pollock, C., Ranquist, D., Reno, M., Szalay, J. R., Thomsen, M. F., Valek, P., Weidner, S., Wilson, R. J., & Zink, J. L. (2017). Electron beams and loss cones in the auroral regions of Jupiter. Geophysical Research Letters, 44, 7131–7139. http://doi.org/10.1002/2017GL073180
André, M., & Eliasson, L. (1992). Electron acceleration by low frequency electric field fluctuations—Electron conics. Geophysical Research Letters, 19(11), 1073–1076. http://doi.org/10.1029/92GL01022
Bolton, S. J., Lunine, J., Stevenson, D., Connerney, J. E. P., Levin, S., Owen, T. C., Bagenal, F., Gautier, D., Ingersoll, A. P., Orton, G. S., Guillot, T., Hubbard, W., Bloxham, J., Coradini, A., Stephens, S. K., Mokashi, P., Thorne, R., & Thorpe, R. (2017). The Juno mission. Space Science Reviews, 213(1-4), 5–37. http://doi.org/10.1007/s11214-017-0429-6
Bonfond, B., Gladstone, G. R., Grodent, D., Greathouse, T. K., Versteeg, M. H., Hue, V., Davis, M. W., Vogt, M. F., Gérard, J. C., Radioti, A., Bolton, S., Levin, S. M., Connerney, J. E. P., Mauk, B. H., Valek, P., Adriani, A., & Kurth, W. S. (2017). Morphology of the UV aurorae Jupiter during Juno's first perijove observations. Geophysical Research Letters, 44, 4463–4471. http://doi.org/10.1002/2017GL073114
Bonfond, B., Grodent, D., Badman, S. V., Saur, J., Gérard, J.-C., & Radioti, A. (2017). Similarity of the Jovian satellite footprints: Spots multiplicity and dynamics. Icarus, 292, 208–217. http://doi.org/10.1016/j.icarus.2017.01.009
Bonfond, B., Grodent, D., Gérard, J.-C., Radioti, A., Dols, V., Delamere, P. A., & Clarke, J. T. (2009). The Io UV footprint: Location, inter-spot distances and tail vertical extent. Journal of Geophysical Research, 114, A07224. http://doi.org/10.1029/2009JA014312
Bonfond, B., Grodent, D., Gérard, J.-C., Radioti, A., Saur, J., & Jacobsen, S. (2008). UV Io footprint leading spot: A key feature for understanding the UV Io footprint multiplicity? Geophysical Research Letters, 35, L05107. http://doi.org/10.1029/2007GL032418
Bonfond, B., Hess, S., Bagenal, F., Gérard, J. C., Grodent, D., Radioti, A., Gustin, J., & Clarke, J. T. (2013). The multiple spots of the Ganymede auroral footprint. Geophysical Research Letters, 40, 4977–4981. http://doi.org/10.1002/grl.50989
Bonfond, B., Saur, J., Grodent, D., Badman, S. V., Bisikalo, D., Shematovich, V., Gérard, J. C., & Radioti, A. (2017). The tails of the satellite auroral footprints at Jupiter. Journal of Geophysical Research: Space Physics, 122, 7985–7996. http://doi.org/10.1002/2017JA024370
Clark, G., Tao, C., Mauk, B. H., Nichols, J., Saur, J., Bunce, E. J., Allegrini, F., Gladstone, R., Bagenal, F., Bolton, S., Bonfond, B., Connerney, J., Ebert, R. W., Gershman, D. J., Haggerty, D., Kimura, T., Kollmann, P., Kotsiaros, S., Kurth, W. S., Levin, S., McComas, D. J., Murakami, G., Paranicas, C., Rymer, A., & Valek, P. (2018). Precipitating electron energy flux and characteristic energies in Jupiter's main auroral region as measured by Juno/JEDI. Journal of Geophysical Research: Space Physics, 123, 7554–7567. https://doi.org/10.1029/2018JA025639
Clarke, J. T., Ajello, J., Ballester, G., Ben Jaffel, L., Connerney, J. E. P., Gérard, J.-C. Gladstone, G. R., Grodent, D., Pryor, W., Trauger, J., & Waite, J. H. (2002). Ultraviolet emissions from the magnetic footprints of Io, Ganymede and Europa on Jupiter. Nature, 415(6), 997–1000.
Connerney, J. E. P., Açuna, M. H., & Ness, N. F. (1981). Modeling the Jovian current sheet and inner magnetosphere. Journal of Geophysical Research, 86, 8370–8384.
Connerney, J. E. P., Benn, M., Bjarno, J. B., Denver, T., Espley, J., Jorgensen, J. L., Jorgensen, P. S., Lawton, P., Malinnikova, A., Merayo, J. M., Murphy, S., Odom, J., Oliversen, R., Schnurr, R., Sheppard, D., & Smith, E. J. (2017). The Juno magnetic field investigation. Space Science Reviews, 213(1-4), 39–138. http://doi.org/10.1007/s11214-017-0334-z
Connerney, J. E. P., Kotsiaros, S., Oliversen, R. J., Espley, J. R., Joergensen, J. L., Joergensen, P. S., Merayo, J. M. G., Herceg, M., Bloxham, J., Moore, K. M., Bolton, S. J., & Levin, S. M. (2018). A new model of Jupiter's magnetic field from Juno's first nine orbits. Geophysical Research Letters, 45, 2590–2596. http://doi.org/10.1002/2018GL077312
Damiano, P. A., Delamere, P. A., Stauffer, B., Ng, C.-S., & Johnson, J. R. (2019). Kinetic simulations of electron acceleration by dispersive scale Alfvén waves in Jupiter's magnetosphere. Geophysical Research Letters, 46, 3043–3051. https://doi.org/10.1029/2018GL081219
Ebert, R. W., Allegrini, F., Bagenal, F., Bolton, S. J., Connerney, J. E. P., Clark, G., Gladstone, G. R., Hue, V., Kurth, W. S., Levin, S., Louarn, P., Mauk, B. H., McComas, D. J., Paranicas, C., Reno, M., Saur, J., Szalay, J. R., Thomsen, M. F., Valek, P., Weidner, S., & Wilson, R. J. (2017). Spatial distribution and properties of 0.1-100 keV electrons in Jupiter's polar auroral region. Geophysical Research Letters, 44, 9199–9207. http://doi.org/10.1002/2017GL075106
Ebert, R. W., Greathouse, T. K., Clark, G., Allegrini, F., Bagenal, F., Bolton, S. J., Connerney, J. E. P., Gladstone, G. R., Imai, M., Hue, V., Kurth, W. S., Levin, S., Louarn, P., Mauk, B. H., McComas, D. J., Paranicas, C., Szalay, J. R., Thomsen, M. F., Valek, P. W., & Wilson, R. J. (2019). Comparing electron energetics and UV brightness in Jupiter's northern polar region during Juno Perijove 5. Geophysical Research Letters, 46, 19–27. http://doi.org/10.1029/2018GL081129
Gérard, J.-C., Bonfond, B., Mauk, B. H., Gladstone, G. R., Yao, Z. H., Greathouse, T. K., Hue, V., Grodent, D., Gkouvelis, L., Kammer, J. A., Versteeg, M., Clark, G., Radioti, A., Connerney, J. E. P., Bolton, S. J., & Levin, S. M. (2019). Contemporaneous observations of Jovian energetic auroral electrons and ultraviolet emissions by the Juno spacecraft. Journal of Geophysical Research: Space Physics, 124, 8298–8317. https://doi.org/10.1029/2019JA026862
Gérard, J.-C., & Singh, V. (1982). A model of energy deposition of energetic electrons and EUV emission in the Jovian and Saturnian atmospheres and implications. Journal of Geophysical Research, 87(A6), 4525–4532. http://doi.org/10.1029/JA087iA06p04525
Gershman, D. J., Connerney, J. E. P., Kotsiaros, S., DiBraccio, G. A., Martos, Y. M., Viñas, A. F., Hue, V., Clark, G., Bagenal, F., Levin, S., & Bolton, S. J. (2019). Alfvénic fluctuations associated with Jupiter's auroral emissions. Geophysical Research Letters, 46, 7157–7165. https://doi.org/10.1029/2019GL082951
Gladstone, G. R., Persyn, S. C., Eterno, J. S., Walther, B. C., Slater, D. C., Davis, M. W., Versteeg, M. H., Persson, K. B., Young, M. K., Dirks, G. J., Sawka, A. O., Tumlinson, J., Sykes, H., Beshears, J., Rhoad, C. L., Cravens, J. P., Winters, G. S., Klar, R. A., Lockhart, W., Piepgrass, B. M., Greathouse, T. K., Trantham, B. J., Wilcox, P. M., Jackson, M. W., Siegmund, O. H. W., Vallerga, J. V., Raffanti, R., Martin, A., Gérard, J. C., Grodent, D. C., Bonfond, B., Marquet, B., & Denis, F. (2017). The ultraviolet spectrograph on NASA's Juno mission. Space Science Reviews, 213(1-4), 447–473. https://doi.org/10.1007/s11214-014-0040-z
Grodent, D. (2015). A brief review of ultraviolet auroral emissions on giant planets. Space Science Reviews, 187(1-4), 23–50. https://doi.org/10.1007/s11214-014-0052-8
Grodent, D., Bonfond, B., Gérard, J. C., Radioti, A., Gustin, J., Clarke, J. T., Nichols, J., & Connerney, J. E. P. (2008). Auroral evidence of a localized magnetic anomaly in Jupiter's northern hemisphere. Journal of Geophysical Research, 113, A09201. http://doi.org/10.1029/2008JA013185
Grodent, D., Bonfond, B., Radioti, A., Gérard, J.-C., Jia, X., Nichols, J. D., & Clarke, J. T. (2009). Auroral footprint of Ganymede. Journal of Geophysical Research, 114, A07212. http://doi.org/10.1029/2009JA014289
Grodent, D., Waite, J. H. J., & Gérard, J.-C. (2001). A self-consistent model of the Jovian auroral thermal structure. Journal of Geophysical Research, 106(A), 12933–12952. http://doi.org/10.1029/2000JA900129
Gustin, J., Bonfond, B., Grodent, D., & Gérard, J. C. (2012). Conversion from HST ACS and STIS auroral counts into brightness, precipitated power and radiated power for H2 giant planets J. Journal of Geophysical Research, 117, A07316. http://doi.org/10.1029/2012JA017607
Jacobsen, S., Neubauer, F. M., Saur, J., & Schilling, N. (2007). Io's nonlinear MHD-wave field in the heterogeneous Jovian magnetosphere. Geophysical Research Letters, 34, L10202. http://doi.org/10.1029/2006GL029187
Hess, S. L. G., Delamere, P. A., Dols, V., Bonfond, B., & Swift, D. (2010). Power transmission and particle acceleration along the Io flux tube. Journal of Geophysical Research, 115(A), A06205. http://doi.org/10.1029/2009JA014928
Jia, X., Walker, R. J., Kivelson, M. G., Khurana, K. K., & Linker, J. A. (2008). Three-dimensional MHD simulations of Ganymede's magnetosphere. Journal of Geophysical Research, 113, A06212. http://doi.org/10.1029/2007JA012748
Klumpar, D. M. (1979). Transversely accelerated ions - An ionospheric source of hot magnetospheric ions. Journal of Geophysical Research, 84(A8), 4229–4237. http://doi.org/10.1029/JA084iA08p04229
Kotsiaros, S., Connerney, J. E. P., Clark, G., Allegrini, F., Gladstone, G. R., Kurth, W. S., Mauk, B. H., Saur, J., Bunce, E. J., Gershman, D. J., Martos, Y. M., Greathouse, T. K., Bolton, S. J., & Levin, S. M. (2019). Birkeland currents in Jupiter's magnetosphere observed by the polar-orbiting Juno spacecraft. Nature Astronomy, 3(10), 904–909. http://doi.org/10.1038/s41550-019-0819-7
Kurth, W. S., Hospodarsky, G. B., Kirchner, D. L., Mokrzycki, B. T., Averkamp, T. F., Robison, W. T., Piker, C. W., Sampl, M., & Zarka, P. (2017). The Juno waves investigation. Space Science Reviews, 213(1-4), 347–392. http://doi.org/10.1007/s11214-017-0396-y
Livadiotis, G., & McComas, D. J. (2013). Understanding kappa distributions: A toolbox for space science and astrophysics. Space Science Reviews, 175(1-4), 183–214. http://doi.org/10.1007/s11214-013-9982-9
Louarn, P., Allegrini, F., McComas, D. J., Valek, P. W., Kurth, W. S., André, N., Bagenal, F., Bolton, S., Ebert, R. W., Imai, M., Levin, S., Szalay, J. R., & Wilson, R. J. (2018). Observation of electron conics by Juno: Implications for radio generation and acceleration processes. Geophysical Research Letters, 45, 9408–9416. http://doi.org/10.1029/2018GL078973
Lundlin, R., Eliasson, L., Hultqvist, B., & Stasiewicz, K. (1987). Plasma energization on auroral field lines as observed by the Viking spacecraft. Geophysical Research Letters, 14(4), 443–446. http://doi.org/10.1029/GL014i004p00443
Lysak, R. L. (1993). Generalized model of the ionospheric Alfvén resonator. Auroral Plasma Dynamics. (1993), 80, 121–128. http://doi.org/10.1029/GM080p0121
Mauk, B. H., Haggerty, D. K., Paranicas, C., Clark, G., Kollmann, P., Rymer, A. M., Bolton, S. J., Levin, S. M., Adriani, A., Allegrini, F., Bagenal, F., Bonfond, B., Connerney, J. E. P., Gladstone, G. R., Kurth, W. S., McComas, D. J., & Valek, P. (2017). Discrete and broadband electron acceleration in Jupiter's powerful aurora. Nature, 549(7670), 66–69. http://doi.org/10.1038/nature23648
Mauk, B. H., Haggerty, D. K., Paranicas, C., Clark, G., Kollmann, P., Rymer, A. M., Mitchell, D. G., Bolton, S. J., Levin, S. M., Adriani, A., Allegrini, F., Bagenal, F., Connerney, J. E. P., Gladstone, G. R., Kurth, W. S., McComas, D. J., Ranquist, D., Szalay, J. R., & Valek, P. (2017). Juno observations of energetic charged particles over Jupiter's polar regions: Analysis of monodirectional and bidirectional electron beams. Geophysical Research Letters, 44, 4410–4418. http://doi.org/10.1002/2016GL072286
McComas, D. J., Alexander, N., Allegrini, F., Bagenal, F., Beebe, C., Clark, G., Crary, F., Desai, M. I., de Los Santos, A., Demkee, D., Dickinson, J., Everett, D., Finley, T., Gribanova, A., Hill, R., Johnson, J., Kofoed, C., Loeffler, C., Louarn, P., Maple, M., Mills, W., Pollock, C., Reno, M., Rodriguez, B., Rouzaud, J., Santos-Costa, D., Valek, P., Weidner, S., Wilson, P., Wilson, R. J., & White, D. (2017). The Jovian auroral distributions experiment (JADE) on the Juno mission to Jupiter. Space Science Reviews, 213(1-4), 547–643. http://doi.org/10.1007/s11214-013-9990-9
Menietti, J. D., & Burch, J. L. (1985). “Electron conic” signatures observed in the nightside auroral zone and over the polar cap. Journal of Geophysical Research, 90(A6), 5345–5353. http://doi.org/10.1029/JA090iA06p05345
Mura, A., Adriani, A., Connerney, J. E. P., Bolton, S., Altieri, F., Bagenal, F., Bonfond, B., Dinelli, B. M., Gérard, J. C., Greathouse, T., Grodent, D., Levin, S., Mauk, B., Moriconi, M. L., Saur, J., Waite, J. H. Jr., Amoroso, M., Cicchetti, A., Fabiano, F., Filacchione, G., Grassi, D., Migliorini, A., Noschese, R., Olivieri, A., Piccioni, G., Plainaki, C., Sindoni, G., Sordini, R., Tosi, F., & Turrini, D. (2018). Juno observations of spot structures and a split tail in Io-induced aurorae on Jupiter. Science, 361(6404), 774–777. http://doi.org/10.1126/science.aat1450
Neubauer, F. M. (1980). Nonlinear standing Alfven wave current system at Io - Theory. Journal of Geophysical Research, 85(A3), 1171–1178. http://doi.org/10.1029/JA085iA03p01171
Paranicas, C., Mauk, B. H., Haggerty, D. K., Clark, G., Kollmann, P., Rymer, A. M., Westlake, J., Allen, R. C., Szalay, J., Ebert, R. W., Sulaiman, A. H., Imai, M., Roussos, E., Krupp, N., Nénon, Q., Bagenal, F., & Bolton, S. J. (2019). Io's effect on energetic charged particles as seen in Juno data. Geophysical Research Letters, 46, 13615–13620. http://doi.org/10.1029/2019GL085393
Paty, C., Paterson, W., & Winglee, R. (2008). Ion energization in Ganymede's magnetosphere: Using multifluid simulations to interpret ion energy spectrograms. Journal of Geophysical Research, 113, A06211. http://doi.org/10.1029/2007JA012848
Saur, J., Grambusch, T., Duling, S., Neubauer, F. M., & Simon, S. (2013). Magnetic energy fluxes in sub-Alfvénic planet star and moon planet interactions. Astronomy and Astrophysics, 552, A119. http://doi.org/10.1051/0004-6361/201118179
Saur, J., Janser, S., Schreiner, A., Clark, G., Mauk, B. H., Kollmann, P., Ebert, R. W., Allegrini, F., Szalay, J. R., & Kotsiaros, S. (2018). Wave-particle interaction of Alfvén waves in Jupiter's magnetosphere: Auroral and magnetospheric particle acceleration. Journal of Geophysical Research: Space Physics, 123, 9560–9573. https://doi.org/10.1029/2018JA025948
Saur, J., Neubauer, F. M., & Schilling, N. (2007). Hemisphere coupling in Enceladus' asymmetric plasma interaction. Journal of Geophysical Research, 112, A11209. http://doi.org/10.1029/2007JA012479
Saur, J., Neubauer, F. M., Strobel, D. F., & Summers, M. E. (1999). Three-dimensional plasma simulation of Io's interaction with the Io plasma torus: Asymmetric plasma flow. Journal of Geophysical Research, 104(A11), 25105–25126.
Sulaiman, A. H., Kurth, W. S., Hospodarsky, G. B., Averkamp, T. F., Ye, S. Y., Menietti, J. D., Farrell, W. M., Gurnett, D. A., Persoon, A. M., Dougherty, M. K., & Hunt, G. J. (2018). Enceladus auroral hiss emissions during Cassini's grand finale. Geophysical Research Letters, 45, 7347–7353. http://doi.org/10.1029/2018GL078130
Szalay, J. R., Allegrini, F., Bagenal, F., Bolton, S., Clark, G., Connerney, J. E. P., Dougherty, L. P., Ebert, R. W., Gershman, D. J., Kurth, W. S., Levin, S., Louarn, P., Mauk, B., McComas, D. J., Paranicas, C., Ranquist, D., Reno, M., Thomsen, M. F., Valek, P. W., Weidner, S., & Wilson, R. J. (2017). Plasma measurements in the Jovian polar region with Juno/JADE. Geophysical Research Letters, 44(14), 7122–7130. http://doi.org/10.1002/2017GL072837
Szalay, J. R., Bagenal, F., Allegrini, F., Bonfond, B., Clark, G., Connerney, J. E. P., Crary, F., Ebert, R. W., Ergun, R. E., Gershman, D. J., Hinton, P. C., Imai, M., Janser, S., McComas, D. J., Paranicas, C., Saur, J., Sulaiman, A. H., Thomsen, M. F., Wilson, R. J., Bolton, S., & Levin, S. M. (2019). Proton acceleration by Io's Alfvénic interaction. Journal of Geophysical Research: Space Physics, 125. https://doi.org/10.1029/2019JA027314
Szalay, J. R., Bonfond, B., Allegrini, F., Bagenal, F., Bolton, S., Clark, G., Connerney, J. E. P., Ebert, R. W., Ergun, R. E., Gladstone, G. R., Grodent, D., Hospodarsky, G. B., Hue, V., Kurth, W. S., Kotsiaros, S., Levin, S. M., Louarn, P., Mauk, B., McComas, D. J., Saur, J., Valek, P. W., & Wilson, R. J. (2018). In situ observations connected to the Io footprint tail aurora. Journal of Geophysical Research: Planets, 123, 3061–3077. https://doi.org/10.1029/2018JE005752
Temerin, M. A., & Cravens, D. (1990). Production of electron conics by stochastic acceleration parallel to the magnetic field. Journal of Geophysical Research, 95(A4), 4285–4290. http://doi.org/10.1029/JA095iA04p04285
Thompson, B. J., & Lysak, R. L. (1996). Electron acceleration by inertial Alfvén waves. Journal of Geophysical Research, 101(A), 5359–5370. http://doi.org/10.1029/95JA03622
Wannawichian, S., Clarke, J. T., & Nichols, J. D. (2010). Ten years of Hubble Space Telescope observations of the variation of the Jovian satellites' auroral footprint brightness. Journal of Geophysical Research, 115, A02206. https://doi.org/10.1029/2009JA014456
Kolmašová, I., Imai, M., Santolík, O., Kurth, W. S., Hospodarsky, G. B., Gurnett, D. A., Connerney, J. E. P., & Bolton, S. J. (2018). Discovery of rapid whistlers close to Jupiter implying lightning rates similar to those on Earth. Nature Astronomy, 2(7), 544–548. http://doi.org/10.1038/s41550-018-0442-z
