scholarly journals Swarm Observations of Dawn/Dusk Asymmetries Between Pedersen Conductance in Upward and Downward Field‐Aligned Current Regions

2021 ◽  
Author(s):  
L. Olifer ◽  
C. Feltman ◽  
R. Ghaffari ◽  
S. Henderson ◽  
D. Huyghebaert ◽  
...  
1993 ◽  
Vol 13 (4) ◽  
pp. 269-274 ◽  
Author(s):  
R.-L. Xu ◽  
Z.-D. Wang ◽  
M. Zhu ◽  
Q.G. Zong

2011 ◽  
Vol 53 (3) ◽  
pp. 035017 ◽  
Author(s):  
I F Shaikhislamov ◽  
Yu P Zakharov ◽  
V G Posukh ◽  
E L Boyarintsev ◽  
A V Melekhov ◽  
...  

1976 ◽  
Vol 15 (3) ◽  
pp. 389-394 ◽  
Author(s):  
A. Hruška

In a layer of magnetic field aligned current, waves corresonding to the slow mode in the limit of no current are absorbed and/or reflected as soon as they enter the layer, while, under certain conditions, the waves corresponding to the fast mode do propagate through the layer.


2016 ◽  
Vol 121 (9) ◽  
pp. 8695-8711 ◽  
Author(s):  
T. Tanaka ◽  
M. Watanabe ◽  
M. Den ◽  
S. Fujita ◽  
Y. Ebihara ◽  
...  

2021 ◽  
Author(s):  
Jianjun Liu

<p>Interplanetary (IP) shock driven sudden compression produces disturbances in the polar ionosphere. Various studies have investigated the effects of IP shock using imagers and radars. However, very few studies have reported the plasma flow reversal and a sudden vertical plasma drift motion following a CME driven IP shock. We report on the cusp ionospheric features following an IP shock impingement on 16 June 2012, using SuperDARN radar and digisonde from the Antarctic Zhongshan Station (ZHO). SuperDARN ZHO radar observed instant strong plasma flow reversal during the IP shock driven sudden impulse (SI) with a suppression in the number of backscatter echoes. Besides, we also report on a “Doppler Impulse” phenomenon, an instant and brief downward plasma motion, were observed by the digisonde in response to the SI and discuss the possible physical causes. Geomagnetic disturbance and convection patterns indicate the flow reversal was generated by the downward field-aligned current (FAC). We speculate that sudden enhancement in ionization associated with SI is responsible for generating the Doppler Impulse phenomenon.</p>


2021 ◽  
Author(s):  
Dave Constable ◽  
Licia Ray ◽  
Sarah Badman ◽  
Chris Arridge ◽  
Chris Lorch ◽  
...  

<p>Since arriving at Jupiter, Juno has observed instances of field-aligned proton and electron beams, in both the upward and downward current regions. These field-aligned beams are identified by inverted-V structures in plasma data, which indicate the presence of potential structures aligned with the magnetic field. The direction, magnitude and location of these potential structures is important, as it affects the characteristics of any resultant field-aligned current. At high latitudes, Juno has observed potentials of 100’s of kV occurring in both directions. Charged particles that are accelerated into Jupiter’s atmosphere and precipitate can excite aurora; likewise, particles accelerated away from the planet can contribute to the population of the magnetosphere.</p> <p>Using a time-varying 1-D spatial, 2-D velocity space Vlasov code, we examine magnetic field lines which extend from Jupiter into the middle magnetosphere. By applying and varying a potential difference at the ionosphere, we can gain insight into the effect these have on the plasma population, the potential structure, and plasma densities along the field line. Utilising a non-uniform mesh, additional resolution is applied in regions where particle acceleration occurs, allowing the spatial and temporal evolution of the plasma to be examined. Here, we present new results from our model, constrained, and compared with recent Juno observations, and examining both the upward and downward current regions.</p>


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