1,1,2,3,4,1- 1Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA (hcao@epss.ucla.edu)
- 2Space Research Corporation, Annapolis, USA
- 3NASA Goddard Space Flight Center, Greenbelt, USA
- 4Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138, USA
Low latitude field-aligned current systems have been well documented at the Earth and reported at Saturn. Here we presented a comprehensive analysis of Juno magnetic field measurements in the low-latitude region within 1 Jovian radii from the surface of Jupiter. After removing the internal magnetic field (and its time variations) as well as the large-scale magnetodisk field, our analysis revealed a “sandwich” structure in the azimuthal component of the Jovian magnetic field, Bphi, with day-night asymmetries: on the dayside, Bphi is positive at mid-to-low latitudes but reverses sign at high latitudes; on the other hand, the pre-dawn side between 3am and 6am features a negative band of Bphi in the low-latitude region.
Based on the observed spatial structures, we propose a day-night asymmetric low-latitude field-aligned current (FAC) system at Jupiter: currents flow from the northern to the southern hemisphere along low-latitude magnetic field lines on the dayside, and reverse direction on the pre-dawn side. These FACs are closed via ionospheric Pedersen currents, forming meridional current loops. We will also discuss the Ohmic heating associated with this current system in the Jovian upper atmosphere.
How to cite: Zhang, W., Cao, H., Connerney, J., Bloxham, J., and Khurana, K.: Low latitude field-aligned currents (FACs) at Jupiter: perspective from Juno MAG , EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–12 Sep 2025, EPSC-DPS2025-454, https://doi.org/10.5194/epsc-dps2025-454, 2025.
