On the apparent equatorward propagation of auroral substorm absorption events at low auroral latitudes

1978 ◽  
Vol 56 (11) ◽  
pp. 1412-1416 ◽  
Author(s):  
Syed Ziauddin ◽  
M. A. Abdu
Keyword(s):  
Time Dependence ◽  
Local Time ◽  
Electric Fields ◽  
Auroral Zone ◽  
Lower Latitude ◽  
Precipitation Region ◽  
Auroral Substorm ◽  
Strong Electric Fields ◽  
Local Time Dependence ◽  
Consistent Tendency

Auroral substorm absorption events observed at two stations. Val d'Or, P.Q. and Ottawa, Ont., located on the lower latitude side of the auroral zone (around L = 4) show a consistent tendency for an apparent equatorward propagation of the events. The observed velocities of propagation do not show any local time dependence or other trends expected from a pure gradient B drift of substorm electrons from the midnight precipitation region to the day side. Though a limited number of events are analysed the results indicate the possible influence of strong electric fields on the drift velocities of the substorm electrons.

scholarly journals On the local time dependence of the penetration of solar wind-induced electric fields to the magnetic equator

2009 ◽  
Vol 27 (8) ◽  
pp. 3027-3030 ◽  
Author(s):  
M. C. Kelley ◽  
E. Dao
Keyword(s):  
Solar Wind ◽  
Time Delay ◽  
Time Dependence ◽  
Local Time ◽  
Electric Fields ◽  
Local Times ◽  
Radio Observatory ◽  
Vertical Drift ◽  
Solar Wind Origin ◽  
Local Time Dependence

Abstract. For a period of a few hours, the penetration of electric fields of solar wind origin is at its highest efficiency. In November 2003, five days of continuous vertical drift data were obtained at the Jicamarca Radio Observatory. Here we have isolated a range of frequencies centered at a few-hour period for a five-day period and have explored the local time dependence of the penetration, along with the time delay due to magnetospheric effects. We find that the latter ranges from 15 to 25 min. For the local time dependence, we find that the period of anti-correlation is roughly from 21:00 to 04:00 LT, with positive correlation at other local times.

Local Time Dependence of Jupiter’s Polar Auroral Emissions Observed by Juno UVS

2021 ◽  
Author(s):  
Thomas Greathouse ◽  
Randy Gladstone ◽  
Maarten Versteeg ◽  
Vincent Hue ◽  
Joshua Kammer ◽  
...  
Keyword(s):  
Time Dependence ◽  
Local Time ◽  
Auroral Emissions ◽  
Local Time Dependence

scholarly journals Magnetic local time dependence of geomagnetic disturbances contributing to the AU and AL indices

2011 ◽  
Vol 29 (4) ◽  
pp. 673-678 ◽  
Author(s):  
S. Tomita ◽  
M. Nosé ◽  
T. Iyemori ◽  
H. Toh ◽  
M. Takeda ◽  
...  
Keyword(s):  
Local Time ◽  
Geomagnetic Field ◽  
Field Data ◽  
Geomagnetic Latitude ◽  
Magnetic Activity ◽  
Auroral Zone ◽  
Magnetic Local Time ◽  
Geomagnetic Disturbances ◽  
Current Systems ◽  
Local Time Dependence

Abstract. The Auroral Electrojet (AE) indices, which are composed of four indices (AU, AL, AE, and AO), are calculated from the geomagnetic field data obtained at 12 geomagnetic observatories that are located in geomagnetic latitude (GMLAT) of 61.7°–70°. The indices have been widely used to study magnetic activity in the auroral zone. In the present study, we examine magnetic local time (MLT) dependence of geomagnetic field variations contributing to the AU and AL indices. We use 1-min geomagnetic field data obtained in 2003. It is found that both AU and AL indices have two ranges of MLT (AU: 15:00–22:00 MLT, ~06:00 MLT; and AL: ~02:00 MLT, 09:00–12:00 MLT) contributing to the index during quiet periods and one MLT range (AU: 15:00–20:00 MLT, and AL: 00:00–06:00 MLT) during disturbed periods. These results are interpreted in terms of various ionospheric current systems, such as, Sqp, Sq, and DP2.

Infrared observations of Saturn's rings by Cassini CIRS : Phase angle and local time dependence

2008 ◽  
Vol 56 (1) ◽  
pp. 117-133 ◽  
Author(s):  
Cedric Leyrat ◽  
Linda J. Spilker ◽  
Nicolas Altobelli ◽  
Stuart Pilorz ◽  
Cecile Ferrari
Keyword(s):  
Time Dependence ◽  
Local Time ◽  
Phase Angle ◽  
Infrared Observations ◽  
Saturn’S Rings ◽  
Saturn's Rings ◽  
Local Time Dependence

scholarly journals Local time dependence of turbulent magnetic fields in Saturn's magnetodisc

2017 ◽  
Vol 122 (4) ◽  
pp. 3972-3984 ◽  
Author(s):  
V. Kaminker ◽  
P. A. Delamere ◽  
C. S. Ng ◽  
T. Dennis ◽  
A. Otto ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Time Dependence ◽  
Local Time ◽  
Local Time Dependence

Magnetic latitude and local time dependence of the amplitude of geomagnetic sudden commencements

2009 ◽  
Vol 114 (A4) ◽  
pp. n/a-n/a ◽  
Author(s):  
Atsuki Shinbori ◽  
Yuji Tsuji ◽  
Takashi Kikuchi ◽  
Tohru Araki ◽  
Shinichi Watari
Keyword(s):  
Time Dependence ◽  
Local Time ◽  
Magnetic Latitude ◽  
Sudden Commencements ◽  
Local Time Dependence
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