Examination of Magnetic Field Signatures and Local Plasma Distribution Variations in Jupiter's Magnetosphere.

Spinning disk of plasma results in deformation of Jupiter's magnetic field from a dipole to a magnetodisc configuration with significant radial and azimuthal components. Polar orbit of the Juno spacecraft enables a comprehensive in situ observation of Jupiter's plasmadisc at different latitudes. Observations from magnetometer and plasma distribution instruments on Juno mission were used to examine interaction of magnetic field and heavy ions in Jupiter's nightside magnetosphere. Power spectrum analysis was used to evaluate magnetic fluctuations inside and outside of the plasmadisc. Extensive radial maps of magnetic activity in Jupiter's nightside magnetosphere are presented. Comprehensive examination of magnetic fluctuations enable to identify local plasma density variations that correlate with plasma distribution count rate fluctuations. Observations of magnetic signatures together with examination of plasma distribution are used to detect features that point to plasma transport inside and outside of Jupiter's plasmadisc. This work shows that plasma in Jupiter's magnetosphere is contained near centrifugal equator and is not a subject to curvature drift that could generate ring currents. Signatures described as current sheet crossings were investigated. On close inspection these signatures show attributes that belong to stand alone formations rather than a single current sheet structure. This work shows that current flow is not an adequate mechanism to explain deformation of Jupiter's magnetic field. Plain Language Summary: The goal of this paper is to use observations from Juno's magnetometer and plasma instruments to investigate structure of Jupiter's magnetosphere. Magnetometer instrument observations are used to construct detailed maps of magnetic activity. Identified magnetic signatures enable to detect structures that point to plasma transport inside and outside of the giant planet's plasmadisc. This study shows that plasma in Jupiter's magnetosphere is contained near centrifugal equator and is not a subject to curvature drift in dipole configuration, that could generate ring currents. Since ring currents are not generated then they cannot be responsible for distorting magnetosphere from dipole in to magnetodisc configuration. Close inspection of magnetic field signatures described as current sheet crossing show that they possess attributes that belong to stand alone individual structures and are not a part of one continuous current sheet formation. It is important to note that multiple publications have been reporting observations of nonexistent magnetosphere deforming "current sheet" since pioneer 10 encounter with Jupiter. Findings in this work warrants a further comprehensive examination of formation of Jupiter's magnetosphere and plasma transport mechanisms within it. Key Points: Shear waves propagate out the plasmadisc while compressive field fluctuations are associated with plasma distribution variationsMagnetic field signatures are used to identify structures that point to plasma transport mechanisms inside and outside of the plasmadiscCurrent flow is not an adequate mechanism to describe deformation of the magnetosphere of Jupiter from dipole to magnetodisc configuration [ABSTRACT FROM AUTHOR]