Local time dependence of turbulent magnetic fields in Saturn's magnetodisc. Issue 4 (1st April 2017)

• Record Type: Journal Article
• Authors: Kaminker, V.; Delamere, P. A.; Ng, C. S.; Dennis, T.; Otto, A.; Ma, X.
• Is Part Of: Journal of geophysical research. Volume 122:Issue 4(2017)
• Page Start: 3972
• Page End: 3984
• Publication Date: 2017-04-01
• Subjects: magnetic fluctuations -- turbulence -- reconnection -- asymmetry -- magnetosphere -- Saturn; Magnetospheric physics -- Periodicals; Space environment -- Periodicals; Cosmic physics -- Periodicals; Planets -- Atmospheres -- Periodicals; Heliosphere (Astrophysics) -- Periodicals; Geophysics -- Periodicals; 523.01
• DOI: 10.1002/2016JA023834
• Languages: English
• ISSNs: 2169-9380

Abstract

Abstract: Net plasma transport in magnetodiscs around giant planets is outward. Observations of plasma temperature have shown that the expanding plasma is heating nonadiabatically during this process. Turbulence has been suggested as a source of heating. However, the mechanism and distribution of magnetic fluctuations in giant magnetospheres are poorly understood. In this study we attempt to quantify the radial and local time dependence of fluctuating magnetic field signatures that are suggestive of turbulence, quantifying the fluctuations in terms of a plasma heating rate density. In addition, the inferred heating rate density is correlated with magnetic field configurations that include azimuthal bend forward/back and magnitude of the equatorial normal component of magnetic field relative to the dipole. We find a significant local time dependence in magnetic fluctuations that is consistent with flux transport triggered in the subsolar and dusk sectors due to magnetodisc reconnection. Key Points: Saturn's magnetodisc exhibits local time asymmetry in terms of magnetic fluctuations Magnetic fluctuations and quantified in terms of turbulent heating The fluctuations are consistent with regions where magnetic reconnection associated with internal flux circulation is operating