Search Publications
Magnetic fluctuations embedded in dipolarization inside geosynchronous orbit and their associated selective acceleration of O+ ions
Kistler, L. M.; Miyashita, Y.; Keika, K. +7 more
We study magnetic fluctuations embedded in dipolarizations in the inner magnetosphere (a geocentric distance of ≤6.6 RE) and their associated ion flux changes, using the Engineering Test Satellite VIII and Active Magnetospheric Particle Tracer Explorers/CCE satellites. We select seven events of dipolarization that occur during the main …
Magnetic clouds and origins in STEREO era
Luhmann, J. G.; Kilpua, E. K. J.; Lynch, B. J. +1 more
When a coronal mass ejection (CME) encounters the Earth, the Earth's electromagnetic environment is disturbed, especially when it is a magnetic cloud (MC) with enhanced, steady, and long-lasting southward field. The speed and the magnetic field of an MC are the two important properties for its geoeffectiveness. The correspondence between a CME and…
Proton acceleration at two-dimensional dipolarization fronts in the magnetotail
Artemyev, A.; Zimbardo, G.; Greco, A.
Transient reconnection events in the planetary magnetotail give rise to fast plasma jets, whose leading edges are called dipolarization fronts. We perform a test particle simulation of ion acceleration in a 2-D model of dipolarization fronts. We study the dependence of acceleration on several parameters of the model. We obtain that the interaction…
Correlation of core field polarity of magnetotail flux ropes with the IMF By: Reconnection guide field dependency
Zhang, T. L.; Nakamura, R.; Baumjohann, W. +2 more
The relationship between the core field and the interplanetary magnetic field (IMF) By has been addressed by spacecraft observations in the magnetotail, but it is not yet fully clear since observations by Slavin et al. (2003) and Borg et al. (2012) show controversial results. In this study, we examine 13 flux ropes from the Cluster obse…
IMF control of the location of Venusian bow shock: The effect of the magnitude of IMF component tangential to the bow shock surface
Barabash, Stas; Zhang, Tielong; Rong, Zhaojin +7 more
The interplanetary magnetic field (IMF) frozen in the solar wind, together with the solar EUV radiation, can significantly affect the location of Venusian bow shock. To recognize the IMF effect on the Venusian bow shock, we investigated 1680 bow shock crossings recorded by Venus Express during the unusually long-lasting solar minimum (May 2006 to …
Evidence of deflected super-Alfvénic electron jet in a reconnection region with weak guide field
Xu, Xiaojun; Yuan, Zhigang; Huang, Shiyong +4 more
Recent numerical simulations demonstrated that electron diffusion region develops into two-scale structure, i.e., the inner electron diffusion region and the outer electron diffusion region. The outer diffusion region is manifested as super-Alfvénic electron jet embedded in central current sheet. However, the electron jets are deflected from neutr…
Spectrum characteristics of electromagnetic ion cyclotron triggered emissions and associated energetic proton dynamics
Omura, Yoshiharu; Shoji, Masafumi
We perform parametric analyses of electromagnetic ion cyclotron (EMIC) triggered emissions with a gradient of the nonuniform ambient magnetic field using a hybrid simulation. According to nonlinear wave growth theory, as the gradient of the ambient magnetic field becomes larger, the theoretical threshold of the wave amplitude becomes larger, altho…
The force-free configuration of flux ropes in geomagnetotail: Cluster observations
Rème, H.; Dunlop, M.; Liu, Z. X. +7 more
Unambiguous knowledge of magnetic field structure and the electric current distribution is critical for understanding the origin, evolution, and related dynamic properties of magnetic flux ropes (MFRs). In this paper, a survey of 13 MFRs in the Earth's magnetotail are conducted by Cluster multipoint analysis, so that their force-free feature, i.e.…
Dependence of IMF By penetration into the neutral sheet on IMF Bz and geomagnetic activity
Dunlop, M.; Cao, JinBin; Duan, Aiying +2 more
The penetration of interplanetary magnetic field (IMF) By into the magnetosphere plays an important role in determining magnetospheric configuration and its dynamics. In this paper, using 9 years of Cluster data at the center of neutral sheet, we statistically study the relations of the penetration of IMF By in the neutral sh…
Saturn's dayside ultraviolet auroras: Evidence for morphological dependence on the direction of the upstream interplanetary magnetic field
Lewis, G. R.; Dougherty, M. K.; Alexeev, I. I. +6 more
We examine a unique data set from seven Hubble Space Telescope (HST) "visits" that imaged Saturn's northern dayside ultraviolet emissions exhibiting usual circumpolar "auroral oval" morphologies, during which Cassini measured the interplanetary magnetic field (IMF) upstream of Saturn's bow shock over intervals of several hours. The auroras general…