Isual Publications 2014

Isual Publications 2014

  • id
  • date time
    2014-04-08 14:38:00
  • 2007
  • 5
  • 蔡禮聿(2007),‘高空短暫發光現象與劇烈天氣的關連性’,國立成功大學物理研究所(碩士論文)
  • 在已知的高空短暫發光現象中,淘氣精靈是ISUAL 觀測資料中為數最多的一類,它與閃電的關聯性也一直是重要的研究問題。我們從超過4000 個淘氣精靈中,篩選中300 個可清楚分辦淘氣精靈型態和其原生閃電的事件,得出無洞型淘氣精靈與有洞型淘氣精靈的出現比率為2/3。這個結果和原先預期應該和雲間閃電(IC)與雲對地閃電(CG)的比例(IC/CG=3/1)相當的結果大不相同。在此,我們使用傳導線模型(TL model)分別模擬IC 或CG 誘發淘氣精靈的臨界峰值電流與回擊速度,試圖解釋ISUAL 結果之可能成因。另外,我們也介紹了2006 年開始執行的追電計畫:內容包含觀測儀器的建置與初步觀測結果,並以實際飛行任務所拍攝的影像,與地面測試時所拍攝到的巨大噴流影像,說明改良後的自動化觀測儀器的觀測能力。

    Among the known species of upper atmospheric transient luminous events, elve is the most abundant in the ISUAL recorded events. The correlation between elves and their causative cloud-to-ground lightning is an interesting problem needed to be addressed. We selected 300 elves with distinct morphology and parent lightnings from the 4000-plus elves recorded by ISUAL since June 2004. From these elves, the ratio between the pancake-shape and the donut-shape elves is deduced to be two to three. This ratio was unexpected since the known occurrence ratio between the inter-cloud discharges (IC) and the cloud-to ground flashes (CG) is known to be around three to one. To explore the root cause behind this discrepancy, this thesis work carried out numerical simulations to determine the minimal peak currents for ICs and CGs to generate these two distinct types of elves. We 
    found that the initiating current for the pancake elves from ICs is substantially higher than that for the donut elves from CGs. In this thesis, we also report our cooperation with the DOTSTAR project. Introduction of JOBS (Jet OBservation System) and initial test images are included. Using the same 
    camera system, we have successfully observed gigantic jets on ground. Hence, we have demonstrated the capability of this imaging system and its readiness for the future aircraft campaigns.

Tuesday the 24th. ISUAL. All rights reserved.