Auroral kilometric radiation at substorm onset

2000 ◽  
Vol 105 (A11) ◽  
pp. 25325-25331 ◽  
Author(s):  
K. Liou ◽  
C.-I. Meng ◽  
A. T. Y. Lui ◽  
P. T. Newell ◽  
R. R. Anderson
Keyword(s):  
Substorm Onset ◽  
Auroral Kilometric Radiation

scholarly journals Vertical evolution of auroral acceleration at substorm onset

2009 ◽  
Vol 27 (2) ◽  
pp. 525-535 ◽  
Author(s):  
A. Morioka ◽  
Y. Miyoshi ◽  
F. Tsuchiya ◽  
H. Misawa ◽  
K. Yumoto ◽  
...  
Keyword(s):  
Substorm Onset ◽  
Acceleration Process ◽  
Acceleration Region ◽  
Auroral Kilometric Radiation ◽  
Auroral Breakup ◽  
Auroral Substorms ◽  
Vertical Evolution ◽  
Field Aligned Current ◽  
Low Altitude ◽  
Two Stages

Abstract. This study describes the onset process of auroral substorms in connection with the vertical evolution of auroral particle acceleration, on the basis of auroral kilometric radiation (AKR) dynamics. We show that the auroral acceleration process at substorm onset basically consists of two stages: (1) appearance/intensification of a low-altitude acceleration region at 4000–5000 km accompanied by initial brightening and (2) breakout of high-altitude field-aligned acceleration above the pre-existing low-altitude acceleration region at 6000–12 000 km, which is followed by auroral breakup and poleward expansion. It is also revealed that this two-stage evolution of auroral acceleration corresponds to the two-step reinforcement of field-aligned current.

Monitoring of the Electron-Acceleration Region with Auroral Kilometric Radiation

2020 ◽  
Vol 60 (5) ◽  
pp. 538-546
Author(s):  
D. V. Chugunin ◽  
A. A. Chernyshov ◽  
I. L. Moiseenko ◽  
M. E. Viktorov ◽  
M. M. Mogilevsky
Keyword(s):  
Electron Acceleration ◽  
Acceleration Region ◽  
Auroral Kilometric Radiation

scholarly journals Decay of the Dst field of geomagnetic disturbance after substorm onset and its implication to storm-substorm relation

1996 ◽  
Vol 14 (6) ◽  
pp. 608-618 ◽  
Author(s):  
T. Iyemori ◽  
D. R. K. Rao
Keyword(s):  
Ring Current ◽  
Geomagnetic Storms ◽  
Sharp Decrease ◽  
Geomagnetic Disturbance ◽  
Substorm Onset ◽  
Significant Development ◽  
H Index ◽  
Magnetospheric Tail ◽  
Storms And Substorms ◽  
Substorm Onsets

Abstract. In order to investigate the causal relationship between magnetic storms and substorms, variations of the mid-latitude geomagnetic indices, ASY (asymmetric part) and SYM (symmetric part), at substorm onsets are examined. Substorm onsets are defined by three different phenomena; (1) a rapid increase in the mid-latitude asymmetric-disturbance indices, ASY-D and ASY-H, with a shape of so-called `mid-latitude positive bay\\'; (2) a sharp decrease in the AL index; (3) an onset of Pi2 geomagnetic pulsation. The positive bays are selected using eye inspection and a pattern-matching technique. The 1-min-resolution SYM-H index, which is essentially the same as the hourly Dst index except in terms of the time resolution, does not show any statistically significant development after the onset of substorms; it tends to decay after the onset rather than to develop. It is suggested by a simple model calculation that the decay of the magnetospheric tail current after substorm onset is responsible for the decay of the Dst field. The relation between the IMF southward turning and the development of the Dst field is re-examined. The results support the idea that the geomagnetic storms and substorms are independent processes; that is, the ring-current development is not the result of the frequent occurrence of substorms, but that of enhanced convection caused by the large southward IMF. A substorm is the process of energy dissipation in the magnetosphere, and its contribution to the storm-time ring-current formation seems to be negligible. The decay of the Dst field after a substorm onset is explained by a magnetospheric energy theorem.

On the three-dimensional magnetic structure of the plasmoid created in the magnetotail at substorm onset

1982 ◽  
Vol 9 (3) ◽  
pp. 203-206 ◽  
Author(s):  
E. W. Hones ◽  
J. Birn ◽  
S. J. Bame ◽  
G. Paschmann ◽  
C. T. Russell
Keyword(s):  
Magnetic Structure ◽  
Three Dimensional ◽  
Substorm Onset

Association of electron precipitation with auroral kilometric radiation

2000 ◽  
Vol 105 (A1) ◽  
pp. 277-289 ◽  
Author(s):  
W. L. Imhof ◽  
M. Walt ◽  
R. R. Anderson ◽  
D. L. Chenette ◽  
J. D. Hawley ◽  
...  
Keyword(s):  
Electron Precipitation ◽  
Auroral Kilometric Radiation
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