Modeling Electron Scattering and Acceleration by Whistler Mode Chorus Waves in Jupiter's Magnetosphere: Effects of Magnetic Field Model, Total Electron Density, and Electron Injections

We evaluate the energetic electron scattering and acceleration due to whistler mode chorus waves using realistic magnetic field and density models in Jupiter's magnetosphere, and study the potential effects of electron injections. The bounce-averaged diffusion coefficients are calculated using the total electron density from the diffusive equilibrium model and the magnetic field strength from the VIP4 internal magnetic field and CAN current sheet model. The electron phase space density evolution due to chorus wave is simulated at $M=10$. The typical chorus waves could cause fast pitch angle scattering loss of electrons from tens to several hundred keV, and gradual acceleration of relativistic electrons at several MeV. The latitudinally varying density and $\text{VIP}4+\text{CAN}$ magnetic field model leads to faster pitch angle scattering and acceleration of electrons at energies above 100 keV than the constant density and dipolar magnetic field model. The simulation is compared to the electron dynamics during an electron injection event observed by Juno on 29 October, 2018. The electron flux is enhanced at low energies during the injection event, and the Fokker Planck simulation indicates an enhanced electron acceleration due to chorus waves subsequent to the injections. The modeling indicates an electron flux increase by nearly 1 order of magnitude within 1 day, suggesting the potentially important role of chorus waves in forming Jupiter's radiation belts after injections.

[1]  W. Li,et al.  Global Distribution of Whistler Mode Waves in Jovian Inner Magnetosphere , 2020, Geophysical Research Letters.

[2]  W. Li,et al.  Energetic Electron Scattering due to Whistler Mode Chorus Waves Using Realistic Magnetic Field and Density Models in Jupiter's Magnetosphere , 2020, Journal of Geophysical Research: Space Physics.

[3]  J. Vandegriff,et al.  Electron Acceleration to MeV Energies at Jupiter and Saturn , 2018, Journal of geophysical research. Space physics.

[4]  Ronald J. Oliversen,et al.  A New Model of Jupiter's Magnetic Field From Juno's First Nine Orbits , 2018 .

[5]  Jingbo Huang,et al.  Radiation belt electron scattering by whistler‐mode chorus in the Jovian magnetosphere: Importance of ambient and wave parameters , 2018 .

[6]  F. Bagenal,et al.  Survey of Voyager plasma science ions at Jupiter: 2. Heavy ions , 2017 .

[7]  E. E. Woodfield,et al.  The origin of Jupiter's outer radiation belt , 2014, 2014 XXXIth URSI General Assembly and Scientific Symposium (URSI GASS).

[8]  B. Ni,et al.  Evolution of the plasma sheet electron pitch angle distribution by whistler-mode chorus waves in non-dipole magnetic fields , 2012 .

[9]  Barry H. Mauk,et al.  Electron radiation belts of the solar system , 2010 .

[10]  D. Gurnett,et al.  Gyro-resonant electron acceleration at Jupiter , 2008 .

[11]  S. Bolton,et al.  Discussing the processes constraining the Jovian synchrotron radio emission's features , 2008 .

[12]  B. Mauk,et al.  Transient aurora on Jupiter from injections of magnetospheric electrons , 2002, Nature.

[13]  S. Bourdarie,et al.  Modeling the inner Jovian electron radiation belt including non-equatorial particles , 2001 .

[14]  J. Connerney,et al.  New models of Jupiter's magnetic field constrained by the Io flux tube footprint , 1998 .

[15]  J. Connerney,et al.  Modeling the Jovian current sheet and inner magnetosphere , 1981 .

[16]  R. Thorne Physics of the Jovian Magnetosphere: Microscopic plasma processes in the Jovian magnetosphere , 1983 .