scholarly journals Van Allen Probes observations of magnetic field dipolarization and its associated O + flux variations in the inner magnetosphere at L  < 6.6

2016 ◽  
Vol 121 (8) ◽  
pp. 7572-7589 ◽  
Author(s):  
M. Nosé ◽  
K. Keika ◽  
C. A. Kletzing ◽  
H. E. Spence ◽  
C. W. Smith ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Inner Magnetosphere ◽  
Van Allen Probes

Calculation of corotation electric field based on Van Allen Probes measurements

2020 ◽  
Author(s):  
Wenlong Liu ◽  
Zhao Zhang
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
Large Scale ◽  
Rotation Period ◽  
Field Measurements ◽  
Inner Magnetosphere ◽  
Dipole Magnetic Field ◽  
Van Allen Probes ◽  
Electric Field Measurements ◽  
Euv Imaging

&lt;p&gt;Corotation electric field is important in the inner magnetosphere topology, which was usually calculated by assuming 24h corotation period. However, some studies suggested that plasmasphere corotation lag exists which leads to the decrease of corotation electric field. In this study, we use electric field measurements from Van Allen Probes mission from 2013 to 2017 to statistically calculate the distribution of large-scale electric field in the inner magnetosphere. A new method is subsequently developed to separate corotation electric field from convection electric field. Our research shows electric field is inversely proportional to the square of L, and, with the assumption of dipole magnetic field, the rotation period of plasmasphere is estimated as 27h, consistent to the results by Sandel et al. [2003] and Burch et al. [2004] with EUV imaging of the plasmasphere. Based on the research, a new empirical model of innermagnetospheric corotation electric field was estibalished, which is significant for a more accurate understanding the large-scale electric field in the inner magnetosphere.&lt;/p&gt;

scholarly journals Strong Southward and Northward Currents Observed in the Inner Plasma Sheet

2019 ◽  
Author(s):  
Yanyan Yang ◽  
Chao Shen ◽  
Yong Ji
Keyword(s):  
Magnetic Field ◽  
Plasma Sheet ◽  
Ring Current ◽  
Generation Mechanism ◽  
Storm Events ◽  
Current Generation ◽  
Inner Magnetosphere ◽  
Latitude Region ◽  
Field Lines ◽  
The Magnetic Field

Abstract. It is generally believed that field aligned currents (FACs) and the ring current (RC) are two dominant parts of the inner magnetosphere. However, using the Cluster spacecraft crossing of the pre-midnight inner plasma sheet in the latitude region between 10° N and 30° N, it is found that, during large storm events, in addition to FACs and the RC, there also exist strong southward and northward currents, which cannot be FACs, because the magnetic field in these regions is mainly along the XY plane. Detailed investigation shows that both magnetic field lines (MFLs) and currents in these regions highly fluctuate. When the curvature of MFLs changes direction in the XY plane, the current also alternatively switches between southward and northward. Further analysis of the current generation mechanism indicates that the most reasonable candidate for the origin of these southward and northward currents is the curvature drift of energetic particles.

scholarly journals Observation of reconnection pulses by Cluster and Double Star

2005 ◽  
Vol 23 (8) ◽  
pp. 2921-2927 ◽  
Author(s):  
X. H. Deng ◽  
R. X. Tang ◽  
R. Nakamura ◽  
W. Baumjohann ◽  
T. L. Zhang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Energetic Electron ◽  
Curvature Vector ◽  
Double Star ◽  
Neutral Sheet ◽  
Inner Magnetosphere ◽  
Point Analysis ◽  
Earthward Flow ◽  
Tailward Flow ◽  
The Magnetic Field

Abstract. During a reconnection event on 7 August 2004, Cluster and Double Star (TC-1) were near the neutral sheet and simultaneously detected the signatures of the reconnection pulses. AT 22:59 UT tailward flow followed by earthward flow was detected by Cluster at about 15 RE, while earthward plasma flow followed by tailward flow was observed by TC-1 at about 10 RE. During the flow reversal from tailward to earthward, the magnetic field Bz changed sign from mainly negative values to positive, and the X component of the magnetic curvature vector switched sign from the tailward direction to the earthward direction, which indicates that the reconnection site (X-line) moved tailward past the Cluster constellation. By using multi-point analysis and observation of energetic electron and ion flux, we study the movement and structure of the current sheet and discuss the braking effect of the earthward flow bursts in the inner magnetosphere.

scholarly journals Magnetic field line curvature induced pitch angle diffusion in the inner magnetosphere

2008 ◽  
Vol 113 (A3) ◽  
pp. n/a-n/a ◽  
Author(s):  
S. L. Young ◽  
R. E. Denton ◽  
B. J. Anderson ◽  
M. K. Hudson
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Magnetic Field Line ◽  
Pitch Angle ◽  
Inner Magnetosphere

scholarly journals Study of the applicability of the curlometer technique with the four Cluster spacecraft in regions close to Earth

2012 ◽  
Vol 30 (3) ◽  
pp. 597-611 ◽  
Author(s):  
S. Grimald ◽  
I. Dandouras ◽  
P. Robert ◽  
E. Lucek
Keyword(s):  
Magnetic Field ◽  
Current Density ◽  
Ring Current ◽  
Current System ◽  
Sufficient Conditions ◽  
Magnetic Activity ◽  
Inner Magnetosphere ◽  
Good Proxy ◽  
The Magnetic Field ◽  
Magnetospheric Current System

Abstract. Knowledge of the inner magnetospheric current system (intensity, boundaries, evolution) is one of the key elements for the understanding of the whole magnetospheric current system. In particular, the calculation of the current density and the study of the changes in the ring current is an active field of research as it is a good proxy for the magnetic activity. The curlometer technique allows the current density to be calculated from the magnetic field measured at four different positions inside a given current sheet using the Maxwell-Ampere's law. In 2009, the CLUSTER perigee pass was located at about 2 RE allowing a study of the ring current deep inside the inner magnetosphere, where the pressure gradient is expected to invert direction. In this paper, we use the curlometer in such an orbit. As the method has never been used so deep inside the inner magnetosphere, this study is a test of the curlometer in a part of the magnetosphere where the magnetic field is very high (about 4000 nT) and changes over small distances (ΔB = 1nT in 1000 km). To do so, the curlometer has been applied to calculate the current density from measured and modelled magnetic fields and for different sizes of the tetrahedron. The results show that the current density cannot be calculated using the curlometer technique at low altitude perigee passes, but that the method may be accurate in a [3 RE; 5 RE] or a [6 RE; 8.3 RE] L-shell range. It also demonstrates that the parameters used to estimate the accuracy of the method are necessary, but not sufficient conditions.

scholarly journals Void structure of O+ ions in the inner magnetosphere observed by the Van Allen Probes

2016 ◽  
Vol 121 (12) ◽  
pp. 11,698-11,713 ◽  
Author(s):  
Y. Nakayama ◽  
Y. Ebihara ◽  
S. Ohtani ◽  
M. Gkioulidou ◽  
K. Takahashi ◽  
...  
Keyword(s):  
Inner Magnetosphere ◽  
Van Allen Probes ◽  
Void Structure

Magnetic field changes in the inner magnetosphere of Jupiter

2001 ◽  
Vol 28 (6) ◽  
pp. 897-902 ◽  
Author(s):  
C.T. Russell ◽  
Z.J. Yu ◽  
K.K. Khurana ◽  
M.G. Kivelson
Keyword(s):  
Magnetic Field ◽  
Inner Magnetosphere

Characteristics of Sudden Commencements Observed by Van Allen Probes in the Inner Magnetosphere

2018 ◽  
Vol 123 (2) ◽  
pp. 1295-1304
Author(s):  
A. Fathy ◽  
K.-H. Kim ◽  
J.-S. Park ◽  
H. Jin ◽  
C. Kletzing ◽  
...  
Keyword(s):  
Inner Magnetosphere ◽  
Van Allen Probes ◽  
Sudden Commencements
Sign in / Sign up

Export Citation Format

Share Document