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Jupiter has a strong magnetic field, and a huge magnetosphere is formed through the solar wind-Jupiter interaction. The generated magnetosphere–ionosphere system is reproduced based on the 9-component Magnetohydrodynamics (MHD) and the current conservation in the ionosphere. Assuming Io plasma emission rate 1.4 t/sec, this paper reproduces self-consistently global magnetic configuration, generations of the field-aligned current (FAC) and aurora, formation of the Io plasma disk at 8–20 RJ, plasma corotation, instability in the plasma disk, transition from the Io plasma disk to the plasma sheet at 20–150 RJ, and the plasmoid ejection. The rotating Io plasma in the disk forms instabilities that promotes radial diffusion. H+ is supplied from the ionosphere along high-latitude magnetic field lines and mixed with heavy ions around 15–20 RJ. Beyond 20 RJ, mixed plasma diffuses further outward by the centrifugal force that can exceed magnetic tension. In the ionosphere, the main oval occurs at 13.7°–15.5° colatitude. The Io disk is inner side of magnetic field lines traced from the low-latitude edge of the main oval. Along magnetic field lines, the main oval is mapped from the outer edge of the Io disk to the entire plasma sheet accompanying rotation delay. Due to the corotation limit, convection is accompanied by plasmoid ejection. Back reaction of plasmoid ejection affects even transport process in the Io disk. The downward FAC occurs in the polar cap showing variability. The region of externally driven Dungey convection seems quite narrow.

Plasmoids have been observed over a broad distance along Earth's magnetotail, from X= -30 RE to -200 RE (X points positively sunward along the sun-Earth line). As described in the near-Earth-neutral-line (NENL) substorm model, reconnection at the NENL causes a plasmoid to be formed and ejected tailward. Because distant-tail (X<-100 RE) plasmoids are correlated one-to-one with large, isolated substorms, they are reliable remote signatures of substorms. Such a correlation, however, does not exist between mid-tail (-100 RE < X <-30 RE) plasmoids and substorms. Also, as indicated in recent studies, magnetic reconnection may be quite localized rather than extending across the entire magnetotail in the dawn-dusk direction. Hence, plasmoid formation and evolution are not well explained by the two-dimensional NENL substorm model. In this dissertation, I will reconcile these seemingly inconsistent observations and describe the formation and expulsion of plasmoids from a three-dimensional perspective using multi-point observations of mid-tail plasmoids and other reconnection-generated structures (dipolarization fronts and anti-dipolarization fronts). To understand the formation and expulsion of plasmoids in three dimensions, I investigate the following unresolved questions: What are the three-dimensional configurations of plasmoids in the near-Earth region, the mid-tail, and the distant-tail? Is local lobe reconnection required for plasmoid ejection? How does a plasmoid that originates near Earth evolve while propagating tailward? My results reveal that a mid-tail plasmoid is typically localized and its azimuthal extent increases with increasing substorm intensity. Local lobe reconnection is not always necessary for plasmoid ejection, and thus a plasmoid can grow due to continuous reconnections on closed field lines. Reconnection produced not only plasmoids, but also anti-dipolarization front (ADF), which shares similar observed properties with plasmoids but represen

Plasmoids have been observed over a broad distance along Earth's magnetotail, from X= -30 RE to -200 RE (X points positively sunward along the sun-Earth line). As described in the near-Earth-neutral-line (NENL) substorm model, reconnection at the NENL causes a plasmoid to be formed and ejected tailward. Because distant-tail (X<-100 RE) plasmoids are correlated one-to-one with large, isolated substorms, they are reliable remote signatures of substorms. Such a correlation, however, does not exist between mid-tail (-100 RE < X <-30 RE) plasmoids and substorms. Also, as indicated in recent studies, magnetic reconnection may be quite localized rather than extending across the entire magnetotail in the dawn-dusk direction. Hence, plasmoid formation and evolution are not well explained by the two-dimensional NENL substorm model. In this dissertation, I will reconcile these seemingly inconsistent observations and describe the formation and expulsion of plasmoids from a three-dimensional perspective using multi-point observations of mid-tail plasmoids and other reconnection-generated structures (dipolarization fronts and anti-dipolarization fronts). To understand the formation and expulsion of plasmoids in three dimensions, I investigate the following unresolved questions: What are the three-dimensional configurations of plasmoids in the near-Earth region, the mid-tail, and the distant-tail? Is local lobe reconnection required for plasmoid ejection? How does a plasmoid that originates near Earth evolve while propagating tailward? My results reveal that a mid-tail plasmoid is typically localized and its azimuthal extent increases with increasing substorm intensity. Local lobe reconnection is not always necessary for plasmoid ejection, and thus a plasmoid can grow due to continuous reconnections on closed field lines. Reconnection produced not only plasmoids, but also anti-dipolarization front (ADF), which shares similar observed properties with plasmoids but represen

At least a dozen well-defined activations were recorded with high spatial resolution during the first 25 min of a substorm commencing at 1959 UT on 3 March 1976. The activations were determined by Pi1 and 2-type magnetic pulsations, magnetic variations and cosmic noise absorption. The activations exhibited differences in intensity, spatial extent and the accompanied auroral behaviour. In all cases but one an impulsive counterclockwise differential equivalent current vortex was observed superimposed on the continuously growing westward electrojet. The high-energy particle precipitation reached its maximum in these vortex regions. In cases where the activations observed on the ground occurred close to the footpoint of the IMP-J satellite, it registered simultaneously (within 2 min) burstlike enhancements of the high-energy particle fluxes. The satellite was at these times 37 RE away from the Earth in the plasma sheet boundary layer. Large, practically isotropic high-energy electron fluxes detected at the satellite during the substorm expansion suggested the existence of a large-scale magnetic loop structure in the far magnetotail. The results give evidence of a time-varying dissipation process operating in an impulsive manner in separate regions of the plasma sheet (within a few RE). According to the magnetic variations at mid-latitude, the intensity of the cross-tail current disruption (or the substorm current wedge) does not respond to these activations in the same impulsive manner, but seems to integrate their effects.           ARK: https://n2t.net/ark:/88439/y017215 Permalink: https://geophysicsjournal.com/article/221 &nbsp

At least a dozen well-defined activations were recorded with high spatial resolution during the first 25 min of a substorm commencing at 1959 UT on 3 March 1976. The activations were determined by Pi1 and 2-type magnetic pulsations, magnetic variations and cosmic noise absorption. The activations exhibited differences in intensity, spatial extent and the accompanied auroral behaviour. In all cases but one an impulsive counterclockwise differential equivalent current vortex was observed superimposed on the continuously growing westward electrojet. The high-energy particle precipitation reached its maximum in these vortex regions. In cases where the activations observed on the ground occurred close to the footpoint of the IMP-J satellite, it registered simultaneously (within 2 min) burstlike enhancements of the high-energy particle fluxes. The satellite was at these times 37 RE away from the Earth in the plasma sheet boundary layer. Large, practically isotropic high-energy electron fluxes detected at the satellite during the substorm expansion suggested the existence of a large-scale magnetic loop structure in the far magnetotail. The results give evidence of a time-varying dissipation process operating in an impulsive manner in separate regions of the plasma sheet (within a few RE). According to the magnetic variations at mid-latitude, the intensity of the cross-tail current disruption (or the substorm current wedge) does not respond to these activations in the same impulsive manner, but seems to integrate their effects.           ARK: https://n2t.net/ark:/88439/y017215 Permalink: https://geophysicsjournal.com/article/221 &nbsp