HR: 1340h
AN: AE23A-0992    [Abstracts]
TI: Gigantic jet observation by the ISUAL payload of FORMOSAT-2 satellite
AU: * Hsu, R
EM: rrhsu@phys.ncku.edu.tw
AF: Department of Physics, National Cheng Kung University, #1 Ta-Hsueh Raod, Tainan, 701 Taiwan
AU: Chen, A B
EM: alfred@phys.ncku.edu.tw
AF: Department of Physics, National Cheng Kung University, #1 Ta-Hsueh Raod, Tainan, 701 Taiwan
AU: Kuo, C
EM: johnny@phys.ncku.edu.tw
AF: Department of Physics, National Cheng Kung University, #1 Ta-Hsueh Raod, Tainan, 701 Taiwan
AU: Lee, Y
EM: yjlee@phys.ncku.edu.tw
AF: Department of Physics, National Cheng Kung University, #1 Ta-Hsueh Raod, Tainan, 701 Taiwan
AU: Su, H
EM: htsu@phys.ncku.edu.tw
AF: Department of Physics, National Cheng Kung University, #1 Ta-Hsueh Raod, Tainan, 701 Taiwan
AU: Fukunishi, H
EM: fuku@pat.geophys.tohoku.ac.jp
AF: Department of Geophysics, Tohoku University, Aramaki-aoba, Sendai, 980-8578 Japan
AU: Takahashi, Y
EM: yukihiro@pat.geophys.tohoku.ac.jp
AF: Department of Geophysics, Tohoku University, Aramaki-aoba, Sendai, 980-8578 Japan
AU: Adachi, T
EM: adachi@pat.geophys.tohoku.ac.jp
AF: Department of Geophysics, Tohoku University, Aramaki-aoba, Sendai, 980-8578 Japan
AU: Yamamoto, K
EM: Katsura@pat.geophys.tohoku.ac.jp
AF: Department of Geophysics, Tohoku University, Aramaki-aoba, Sendai, 980-8578 Japan
AU: Frey, H U
EM: hfrey@ssl.berkeley.edu
AF: Space Science Laboratory, University of California, Berkeley, 7 Gauss Way, Berkeley, CA 94720 United States
AU: Mende, S B
EM: mende@ssl.berkeley.edu
AF: Space Science Laboratory, University of California, Berkeley, 7 Gauss Way, Berkeley, CA 94720 United States
AU: Lee, L
EM: loulee@narl.org.tw
AF: National Applied Research Laboratories, 3F No. 106 Sec 2 Hoping E. Rd., Taipei, 106 Taiwan
AB: Gigantic jet is a kind of transient luminous events (TLEs), which was first discovered in 2002 [Su et al]. Based on the 16ms time resolution black/white images, three luminous stages, called leading jet, fully-developed jet, and trailing jet, were identified. At the fully-developed stage, the fully-extended luminous body connected the cloud top at 15km with the E-layer ionosphere at 90km. The leading jet, which can be viewed as the pre-stage of the fully- developed jet, behaved like a stepped leader of cloud-to-ground (CG) lightning. The trailing jets have similar dynamical evolution features as the blue jets, where a funnel-shape jet emerged from the cloud-top and propagating upward. The luminous period of these jets lasted from 300 ms to 500 ms, which is longer than typical sprites but is shorter than that of the large blue jets observed by Pasko et al (2002). From the associated ELF emissions, the charge moment changes of GJs were estimated to be 1000-2000C-km and the polarity was determined to be negative. Both optical and radio signals suggested that GJs were not CG-induced events, and likely are true discharges from thundercloud to the ionosphere. Among the TLE events recorded by the ISUAL payload on the FORMOSAT-2 satellite, a gigantic jet event was identified. The spectrophotometric data recorded by the ISUAL SP reveals that the GJ is more energetic than sprites. The expected spatial-temporal properties of GJ were confirmed by the ISUAL array photometer. The ISUAL AP data indicates that the electric field intensity of GJ is much larger than the sprite QE field intensity above 70 km. Both ISUAL imager and AP data demonstrate that the fully-developed stage in GJ truly is an upward discharge from the cloud-top to ionosphere and plays the similar role as the return stroke in cloud-to-ground lightning. In this paper, the ISUAL data on this fantastic event will be presented, including its spectroscopic data and dynamical properties at 1ms time resolution. The corresponding ELF signals, observed by Onagawa station in Japan and Esrange station in Sweden, will also be shown.
DE: 0340 Middle atmosphere: composition and chemistry
DE: 2427 Ionosphere/atmosphere interactions (0335)
DE: 3304 Atmospheric electricity
DE: 3324 Lightning
DE: 3334 Middle atmosphere dynamics (0341, 0342)
SC: Atmospheric and Space Electricity [AE]
MN: Fall Meeting 2005