Advanced Search



ISSN  2096-3955

CN  10-1502/P

Citation: Yuan, C. J., Zuo, Y. Q., Roussos, E., Wei, Y., Hao, Y. X., Sun, Y. X. and Krupp, N. (2021). Large-scale episodic enhancements of relativistic electron intensities in Jupiter's radiation belt. Earth Planet. Phys., 5(4), 314–326.

2021, 5(4): 314-326. doi: 10.26464/epp2021037


Large-scale episodic enhancements of relativistic electron intensities in Jupiter's radiation belt


Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China


Innovation Academy for Earth Science, Chinese Academy of Sciences, Beijing 100029, China


University of Chinese Academy of Sciences, Beijing 100049, China


Max Planck Institute for Solar System Research, Justus-von-Liebig-Weg 3, Göttingen, 37077, Germany


Institute of Space Physics and Applied Technology, Peking University, Beijing 100871, China

Corresponding author: Elias Roussos,

Received Date: 2021-03-19
Web Publishing Date: 2021-06-18

Previous studies indicate that, in the Jovian magnetosphere, the long-term trend of the radial profile of relativistic electron intensities is primarily shaped by slow radial diffusion. However, measurements by the Galileo spacecraft reveal the existence of transient increases in MeV electron intensities well above the ambient distribution. It is unclear how common such transient enhancements are, and to which dynamic processes in Jupiter's magnetosphere their occurrence is linked. We investigate the radial distributions of $>$11 MeV and $>$1 MeV electron intensities from $9R_{J}$ to $40R_{J}$ ($R_{J}=71492\;{\rm{km}}$ denotes the Jovian radius), measured by the Galileo spacecraft from 1996 to 2002. We find transient enhancements of MeV electrons during seven Galileo crossings, mostly occurring around ~20RJ. An apparent dawn-dusk asymmetry of their occurrence is resolved, with a majority of events discovered at dawn. This dawn-dusk asymmetry, as well as the average recurrence time scale of a few days, implies a potential relationship between the MeV electron transients and the storm-like dynamics in the middle and outer magnetosphere detected using a variety of Galileo, Juno and remote sensing aurora observations. We suggest that the observations of some of these transients in the inner magnetosphere may result from a synergy between the convective transport by a large-scale dawn-dusk electric field and the sources provided by injections in the middle magnetosphere.

Key words: radiation belt, Jupiter, relativistic electrons, magnetosphere

Andriopoulou, M., Roussos, E., Krupp, N., Paranicas, C., Thomsen, M., Krimigis, S., Dougherty, M. K., and Glassmeier, K. H. (2012). A noon-to-midnight electric field and nightside dynamics in Saturn’s inner magnetosphere, using microsignature observations. Icarus, 220(2), 503–513.

Andriopoulou, M., Roussos, E., Krupp, N., Paranicas, C., Thomsen, M., Krimigis, S., Dougherty, M. K., and Glassmeier, K. H. (2014). Spatial and temporal dependence of the convective electric field in Saturn’s inner magnetosphere. Icarus, 229, 57–70.

Barbosa, D. D., and Kivelson, M. G. (1983). Dawn-dusk electric field asymmetry of the Io plasma torus. Geophys. Res. Lett., 10(3), 210–213.

Birmingham, T. J. (1982). Charged particle motions in the distended magnetospheres of Jupiter and Saturn. J. Geophys. Res., 87(A9), 7421–7430.

Bolton, S. J., Janssen, M., Thorne, R., Levin, S., Klein, M., Gulkis, S., Bastian, T., Sault, R., Elachi, C., … West, R. (2002). Ultra-relativistic electrons in Jupiter’s radiation belts. Nature, 415(6875), 987–991.

Drake, F. D., and Hvatum, S. (1959). Non-thermal microwave radiation from Jupiter. Astron. J., 64, 329–330.

Ebert, R. W., Bagenal, F., McComas, D. J., and Fowler, C. M. (2014). A survey of solar wind conditions at 5 AU: a tool for interpreting solar wind-magnetosphere interactions at Jupiter. Front. Astron. Space Sci., 1, 4.

Fillius, R. W., and McIlwain, C. E. (1974). Measurements of the Jovian radiation belts. J. Geophys. Res., 79(25), 3589–3599.

Garrett, H. B., and Jun, I. (2021). First adiabatic invariants and phase space densities for the Jovian electron and proton radiation belts—Galileo and GIRE3 estimates. J. Geophys. Res., 126(1), e2020JA028593.

Grodent, D., Bonfond, B., Yao, Z., Gérard, J. C., Radioti, A., Dumont, M., Palmaerts, B., Adriani, A., Badman, S. V., … Valek, P. (2018). Jupiter’s aurora observed With HST During Juno orbits 3 to 7. J. Geophys. Res., 123(5), 3299–3319.

Guio, P., Staniland, N. R., Achilleos, N., and Arridge, C. S. (2020). Trapped particle motion in Magnetodisk fields. J. Geophys. Res., 125(7), e2020JA027827.

Han, S., Murakami, G., Kita, H., Tsuchiya, F., Tao, C., Misawa, H., Yamazaki, A., and Nakamura, M. (2018). Investigating solar wind-driven electric field influence on long-term dynamics of Jovian synchrotron radiation. J. Geophys. Res., 123(11), 9508–9516.

Hao, Y. X., Sun, Y. X., Roussos, E., Liu, Y., Kollmann, P., Yuan, C. J., Krupp, N., Paranicas, C., Zhou, X. Z., and Murakami, G. (2020). The Formation of Saturn’s and Jupiter’s electron radiation belts by Magnetospheric electric fields. Astrophys. J. Lett., 905(1), L10.

Ip, W. H., and Goertz, C. K. (1983). An interpretation of the dawn–dusk asymmetry of UV emission from the Io plasma torus. Nature, 302(5905), 232–233.

Jun, I., Garrett, H. B., Swimm, R., Evans, R. W., and Clough, G. (2005). Statistics of the variations of the high-energy electron population between 7 and 28 Jovian radii as measured by the Galileo spacecraft. Icarus, 178(2), 386–394.

Khurana, K. K. (1992). A generalized hinged-magnetodisc model of Jupiter’s Nightside current sheet. J. Geophys. Res., 97(A5), 6269–6276.

Kollmann, P., Roussos, E., Paranicas, C., Woodfield, E. E., Mauk, B. H., Clark, G., Smith, D. C., and Vandegriff, J. (2018). Electron acceleration to MeV energies at Jupiter and Saturn. J. Geophys. Res., 123(11), 9110–9129.

Kollmann, P., Paranicas, C., Lagg, A., Roussos, E., Lee-Payne, Z. H., Kusterer, M., Smith, D., Krupp, N., and Vandegriff, J. (2020). Galileo/EPD user guide. Retrieved from

Kronberg, E. A., Woch, J., Krupp, N., Lagg, A., Khurana, K. K., and Glassmeier, K. H. (2005). Mass release at Jupiter: Substorm-like processes in the Jovian magnetotail. J. Geophys. Res., 110(A3), A03211.

Krupp, N., Woch, J., Lagg, A., Wilken, B., Livi, S., and Williams, D. J. (1998). Energetic particle bursts in the predawn Jovian magnetotail. Geophys. Res. Lett., 25(8), 1249–1252.

Menietti, J. D., Groene, J. B., Averkamp, T. F., Horne, R. B., Woodfield, E. E., Shprits, Y. Y., de Soria-Santacruz Pich, M., and Gurnett, D. A. (2016). Survey of whistler mode chorus intensity at Jupiter. J. Geophys. Res., 121(10), 9758–9770.

Mitchell, D. G., Krimigis, S. M., Paranicas, C., Brandt, P. C., Carbary, J. F., Roelof, E. C., Kurth, W. S., Gurnett, D. A., Clarke, J. T., … Pryor, W. R. (2009). Recurrent energization of plasma in the midnight-to-dawn quadrant of Saturn’s magnetosphere, and its relationship to auroral UV and radio emissions. Planet. Space Sci., 57(14-15), 1732–1742.

Murakami, G., Yoshioka, K., Yamazaki, A., Tsuchiya, F., Kimura, T., Tao, C., Kita, H., Kagitani, M., Sakanoi, T., … Fujimoto, M. (2016). Response of Jupiter’s inner magnetosphere to the solar wind derived from extreme ultraviolet monitoring of the Io plasma torus. Geophysical Research Letters, 43(24), 12308–12316.

Northrop, T. G., Goertz, C. K., and Thomsen, M. F. (1974). The magnetosphere of Jupiter as observed with Pioneer 10: 2. Nonrigid rotation of the magnetodisc. J. Geophys. Res., 79(25), 3579–3582.

Paranicas, C., Mitchell, D. G., Roussos, E., Kollmann, P., Krupp, N., Müller, A. L., Krimigis, S. M., Turner, F. S., Brandt, P. C., … Johnson, R. E. (2010). Transport of energetic electrons into Saturn’s inner magnetosphere. J. Geophys. Res., 115(A9), A09214.

Roussos, E., Kollmann, P., Krupp, N., Paranicas, C., Dialynas, K., Sergis, N., Mitchell, D. G., Hamilton, D. C., and Krimigis, S. M. (2018). Drift-resonant, relativistic electron acceleration at the outer planets: Insights from the response of Saturn’s radiation belts to Magnetospheric storms. Icarus, 305, 160–173.

Roussos, E., Kollmann, P., Krupp, N., Paranicas, C., Dialynas, K., Jones, G. H., Mitchell, D. G., Krimigis, S. M., and Cooper, J. F. (2019). Sources, sinks, and transport of energetic electrons Near Saturn’s Main Rings. Geophys. Res. Lett., 46(7), 3590–3598.

Russell, C. T., Fieseler, P. D., Bindshadler, D., Yu, Z. J., Joy, S. P., Khurana, K. K., and Kivelson, M. G. (2001). Large scale changes in the highly energetic charged particles in the region of the Io torus. Advances in Space Research, 28(10), 1495–1500.

Selesnick, R. S., Cohen, C. M. S., and Khurana, K. K. (2001). Energetic ion dynamics in Jupiter’s plasma sheet. J. Geophys. Res., 106(A9), 18895–18905.

Simpson, J. A., Hamilton, D. C., McKibben, R. B., Mogro-Campero, A., Pyle, K. R., and Tuzzolino, A. J. (1974). The protons and electrons trapped in the Jovian dipole magnetic field region and their interaction with Io. J. Geophys. Res., 79(25), 3522–3544.

Sorensen, T. C., Armstrong, T. P., Pavanasam, A. G., and Taherion, S. (2005). Galileo energetic particle detector observations of the spatial distributions and energy spectra of >1 and >11 MeV electrons in the 10-40 RJ region of the Jovian magnetosphere. Icarus, 178(2), 395–405.

Sun, Y. X., Roussos, E., Krupp, N., Zong, Q. G., Kollmann, P., and Zhou, X. Z. (2019). Spectral signatures of adiabatic electron acceleration at Saturn Through Corotation drift cancelation. Geophys. Res. Lett., 46(17-18), 10240–10249.

Swithenbank‐Harris, B. G., Nichols, J. D., Allegrini, F., Bagenal, F., Bonfond, B., Bunce, E. J., Clark, G., Kurth, W. S., Kurth, B. H., and Wilson, R. J. (2021). Simultaneous observation of an Auroral dawn storm with the Hubble space telescope and Juno. J. Geophys. Res., 126(4), e2020JA028717.

Tao, C., Kataoka, R., Fukunishi, H., Takahashi, Y., and Yokoyama, T. (2005). Magnetic field variations in the Jovian magnetotail induced by solar wind dynamic pressure enhancements. J. Geophys. Res., 110(A11), A11208.

Thomsen, M. F., Roussos, E., Andriopoulou, M., Kollmann, P., Arridge, C. S., Paranicas, C. P., Gurnett, D. A., Powell, R. L., Tokar, R. L., and Young, D. T. (2012). Saturn’s inner magnetospheric convection pattern: Further evidence. J. Geophys. Res., 117(A9), A09208.

Vasyliunas, V. M. (1983). Plasma distribution and flow. In A. J. Dessler (Ed.), Physics of the Jovian Magnetosphere (pp. 395-453). Cambridge: Cambridge University Press.

Vogt, M. F., Kivelson, M. G., Khurana, K. K., Joy, S. P., and Walker, R. J. (2010). Reconnection and flows in the Jovian magnetotail as inferred from magnetometer observations. J. Geophys. Res., 115(A6), A06219.

Vogt, M. F., Gyalay, S., Kronberg, E. A., Bunce, E. J., Kurth, W. S., Zieger, B., and Tao, C. (2019). Solar wind interaction with Jupiter’s magnetosphere: A statistical study of Galileo in situ data and modeled upstream solar wind conditions. J. Geophys. Res., 124(12), 10170–10199.

Vogt, M. F., Connerney, J. E. P., DiBraccio, G. A., Wilson, R. J., Thomsen, M. F., Ebert, R. W., Clark, G. B., Paranicas, C., Kurth, W. S., … Bolton, S. J. (2020). Magnetotail reconnection at Jupiter: A survey of Juno magnetic field observations. J. Geophys. Res., 125(3), e2019JA027486.

Williams, D. J., McEntire, R. W., Jaskulek, S., and Wilken, B. (1992). The Galileo energetic particles detector. Space Sci. Rev., 60(1), 385–412.

Woch, J., Krupp, N., Lagg, A., Wilken, B., Livi, S., and Williams, D. J. (1998). Quasi‐periodic modulations of the Jovian magnetotail. Geophys. Res. Lett., 25(8), 1253–1256.

Woch, J., Krupp, N., and Lagg, A. (2002). Particle bursts in the Jovian magnetosphere: Evidence for a near-Jupiter neutral line. Geophys. Res. Lett., 29(7), 42-1–42-4.

Woodfield, E. E., Horne, R. B., Glauert, S. A., Menietti, J. D., and Shprits, Y. Y. (2014). The origin of Jupiter’s outer radiation belt. J. Geophys. Res., 119(5), 3490–3502.

Yao, Z. H., Bonfond, B., Clark, G., Grodent, D., Dunn, W. R., Vogt, M. F., Guo, R. L., Mauk, B. H., Connerney, J. E. P., … Bolton, S. J. (2020). Reconnection- and Dipolarization-driven Auroral dawn storms and injections. J. Geophys. Res., 125(8), e2019JA027663.

Yuan, C. I., Roussos, E., Wei, Y., and Krupp, N. (2020). Sustaining Saturn’s electron radiation belts through episodic, global-scale relativistic electron flux enhancements. J. Geophys. Res., 125(5), e2019JA027621.

Zieger, B., and Hansen, K. C. (2008). Statistical validation of a solar wind propagation model from 1 to 10 AU. J. Geophys. Res., 113(A8), A08107.


YuXian Wang, XiaoCheng Guo, BinBin Tang, WenYa Li, Chi Wang, 2018: Modeling the Jovian magnetosphere under an antiparallel interplanetary magnetic field from a global MHD simulation, Earth and Planetary Physics, 2, 303-309. doi: 10.26464/epp2018028


ChaoLing Tang, Xu Wang, BinBin Ni, ZhengPeng Su, JiChun Zhang, 2022: The 600 keV electron injections in the Earth’s outer radiation belt: A statistical study, Earth and Planetary Physics, 6, 149-160. doi: 10.26464/epp2022012


ZhongLei Gao, ZhenPeng Su, FuLiang Xiao, HuiNan Zheng, YuMing Wang, Shui Wang, H. E. Spence, G. D. Reeves, D. N. Baker, J. B. Blake, H. O. Funsten, 2018: Exohiss wave enhancement following substorm electron injection in the dayside magnetosphere, Earth and Planetary Physics, 2, 359-370. doi: 10.26464/epp2018033


Zhi Li, QuanMing Lu, RongSheng Wang, XinLiang Gao, HuaYue Chen, 2019: In situ evidence of resonant interactions between energetic electrons and whistler waves in magnetopause reconnection, Earth and Planetary Physics, 3, 467-473. doi: 10.26464/epp2019048


JianYong Lu, HanXiao Zhang, Ming Wang, ChunLi Gu, HaiYan Guan, 2019: Magnetosphere response to the IMF turning from north to south, Earth and Planetary Physics, 3, 8-16. doi: 10.26464/epp2019002


Laurent Lamy, Baptiste Cecconi, Stéphane Aicardi, C. K. Louis, 2022: Comment on “Locating the source field lines of Jovian decametric radio emissions” by YuMing Wang et al., Earth and Planetary Physics, 6, 10-12. doi: 10.26464/epp2022018


Jun Cui, ZhaoJin Rong, Yong Wei, YuMing Wang, 2020: Recent investigations of the near-Mars space environment by the planetary aeronomy and space physics community in China, Earth and Planetary Physics, 4, 1-3. doi: 10.26464/epp2020001


BinBin Ni, Jing Huang, YaSong Ge, Jun Cui, Yong Wei, XuDong Gu, Song Fu, Zheng Xiang, ZhengYu Zhao, 2018: Radiation belt electron scattering by whistler-mode chorus in the Jovian magnetosphere: Importance of ambient and wave parameters, Earth and Planetary Physics, 2, 1-14. doi: 10.26464/epp2018001


Jing Huang, XuDong Gu, BinBin Ni, Qiong Luo, Song Fu, Zheng Xiang, WenXun Zhang, 2018: Importance of electron distribution profiles to chorus wave driven evolution of Jovian radiation belt electrons, Earth and Planetary Physics, 2, 371-383. doi: 10.26464/epp2018035


Konrad Sauer, Klaus Baumgärtel, Richard Sydora, 2020: Gap formation around Ωe/2 and generation of low-band whistler waves by Landau-resonant electrons in the magnetosphere: Predictions from dispersion theory, Earth and Planetary Physics, 4, 138-150. doi: 10.26464/epp2020020


LongHui Yuan, YuFeng Lin, Chris A. Jones, 2021: Influence of reference states on Jupiter’s dynamo simulations, Earth and Planetary Physics, 5, 305-313. doi: 10.26464/epp2021041


Xin Ma, Zheng Xiang, BinBin Ni, Song Fu, Xing Cao, Man Hua, DeYu Guo, YingJie Guo, XuDong Gu, ZeYuan Liu, Qi Zhu, 2020: On the loss mechanisms of radiation belt electron dropouts during the 12 September 2014 geomagnetic storm, Earth and Planetary Physics, 4, 598-610. doi: 10.26464/epp2020060


Ying Xiong, Lun Xie, SuiYan Fu, BinBin Ni, ZuYin Pu, 2021: Non-storm erosion of MeV electron outer radiation belt down to L* < 4.0 associated with successive enhancements of solar wind density, Earth and Planetary Physics, 5, 581-591. doi: 10.26464/epp2021051


DongDong Ni, 2020: Signature of helium rain and dilute cores in Jupiter's interior from empirical equations of state, Earth and Planetary Physics, 4, 111-119. doi: 10.26464/epp2020017


QingHua Zhou, YunXiang Chen, FuLiang Xiao, Sai Zhang, Si Liu, Chang Yang, YiHua He, ZhongLei Gao, 2022: A machine learning-based electron density (MLED) model in the inner magnetosphere, Earth and Planetary Physics. doi: 10.26464/epp2022036


Hao Zhang, YaBing Wang, JianYong Lu, 2022: Statistical study of “trunk-like” heavy ion structures in the inner magnetosphere, Earth and Planetary Physics. doi: 10.26464/epp2022032


Tong Dang, JiuHou Lei, XianKang Dou, WeiXing Wan, 2017: A simulation study of 630 nm and 557.7 nm airglow variations due to dissociative recombination and thermal electrons by high-power HF heating, Earth and Planetary Physics, 1, 44-52. doi: 10.26464/epp2017006


LiangQuan Ge, JianKun Zhao, QingXian Zhang, YaoYao Luo, Yi Gu, 2018: Mapping of the lunar surface by average atomic number based on positron annihilation radiation from Chang’e-1, Earth and Planetary Physics, 2, 238-246. doi: 10.26464/epp2018023


ChunQin Wang, Zheng Chang, XiaoXin Zhang, GuoHong Shen, ShenYi Zhang, YueQiang Sun, JiaWei Li, Tao Jing, HuanXin Zhang, Ying Sun, BinQuan Zhang, 2020: Proton belt variations traced back to Fengyun-1C satellite observations, Earth and Planetary Physics, 4, 611-618. doi: 10.26464/epp2020069

Article Metrics
  • PDF Downloads()
  • Abstract views()
  • HTML views()
  • Cited by(0)

Figures And Tables

Large-scale episodic enhancements of relativistic electron intensities in Jupiter's radiation belt

ChongJing Yuan, YiQiao Zuo, Elias Roussos, Yong Wei, YiXin Hao, YiXin Sun, Norbert Krupp