國立中央大學太空科學與科技研究中心
Center for Astronautical Physics and Engineering

The Mid-Latitude Trough and the Plasmapause Observed by DEMETER Satellite


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●演講者:陳朝焱
●演講時間:2018年7月20日(五) 14:00
●演講題目:利用DEMETER衛星研究中緯度槽與電漿層頂
The Mid-Latitude Trough and the Plasmapause Observed by DEMETER Satellite


Abstract:

This paper concurrently investigates the mid-latitude trough and the plasmapause
positions in the ionosphere by co-located measurements of the electron density,
electron temperature, and whistler count probed by DEMETER (Detection of Electro-
Magnetic Emissions Transmitted from Earthquake Regions) satellite in the
daytime/nighttime at 1030/2230 LT during the 4-year period of 2006–2009. More
than 13000 DEMETER orbits of the electron density and the electron temperature are
used to search the trough position, while the same amount of the whistler count is
employed to determine the plasmapause position at the satellite altitude. At nighttime,
the plasmapause is more sensitive to solar activity, which moves equatorward
1.0–1.2° form the low to high solar activity of the study period. On the other hand,
the mid-latitude trough is more sensitive to seasonal variation, which shifts poleward
1.7–2.5° from the Winter to Summer month in the study period. The mid-latitude
trough usually appears in the poleward side of the plasmapause during the study
period. Both of the mid-latitude trough and the plasmapause move equatorward
during the magnetic disturbed condition. For the magnetic disturbed Kp≥6-, the mid-
latitude trough can appear in the equatorward side of the plasmapause. At the
daytime, the trough cannot be clearly allocated, while the plasmapause is observable.
The daytime plasmapause mainly appears in the equatorward side of the nighttime
one. Its responses to the solar activity and to the magnetic disturbed are similar to the
nighttime plasmapause.