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작성일 : 17-10-13 16:51
10월 17일(화요일) 우주과학과 세미나 안내(Dr. Jong-Sun Park)
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안녕하세요우주과학과, 우주탐사학과 여러분.
 
이번 세미나 10 17일 오후 4 30천문대 영상실에서 있습니다.
대만 국립중앙대학교의 박종선 박사님서 "IMF BZ dependence of EMIC wave occurrence in the magnetosphere: THEMIS observations"에 관한 강연을 해 주실 예정입니다.

강연은 한국어로 진행되며, 초록은 아래에 나타나있습니다. 세미나 참석을 원하시는 분은 세미나 10분 전까지 입실해 주시기 바랍니다. 많은 참석 부탁드립니다. 감사합니다.
 
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Dear Colleagues,
 
There will be an Astronomy and Space Science seminar on 10/17, 4:30 PM, in the Auditorium, Kyung Hee University Astronomical Observatory.

Dr. Jong-Sun Park of National Central University will give a presentation about "IMF BZ dependence of EMIC wave occurrence in the magnetosphere: THEMIS observations".
 
The language of the seminar will be Korean and abstract is shown below.
 
You are asked to join the seminar five to ten minutes before it starts. Your attendance will greatly be appreciated.
  
Thank you.


* Abstract:

 We investigate the L-MLT (i.e., L-shall versus magnetic local time) distributions of electromagnetic ion cyclotron (EMIC) waves, using the Time History of Events and Macroscale Interactions during Substorms (THEMIS) data from 2009 to 2014, under prolonged (more than four hours) intervals of northward and southward interplanetary magnetic fields (IMFs).  H-band EMIC waves show high occurrence in the dawn-to-postnoon sector (0400-1600 MLT) at L> ~7 for northward IMFs.  On the other hand, for southward IMFs H-band EMIC waves occur in the morning-to-afternoon sector (0700-1500 MLT), and no strong wave activity is found in the dawn sector (0400-0700 MLT).  H-band EMIC waves are frequently observed in the region where the ambient temperature anisotropy for the energetic ions (~1-25 keV) is high.  He-band EMIC waves show high occurrence in the noon-to-dusk sector (1100-2000 MLT) for both IMF BZ conditions.  In the dusk sector, however, the high occurrence region is shifted into the inner L-shell for southward IMFs (L <8) in contrast to that observed for northward IMFs (L <10).  He-band EMIC waves are shown to be generated in the region where the total plasma density is high (especially near the plasmapause).  The occurrence rates of EMIC waves are lower overall for southward IMFs than for northward IMFs for both H-band and He-band waves.  We suggest that an increase of heavy ion (i.e., He+ and O+) concentration is likely associated with low occurrence rates in both frequency bands for southward IMFs.