這項研究的目的是為了驗證一種高空閃電巨大噴流(Gigantic jet)是否產生綠魅(Green ghost)的現象。綠魅是一個目前經文獻證明在一種高空閃電——紅色精靈(Red sprite)產生後的綠色氣暉，產生原因主要是紅色精靈的氣體放電中，自由電子受到背景電場的加速，激發背景氧原子O(3P)到激發態O(1S)，O(1S)再躍遷到低階軌域O(1D)，同時將能量以557.7nm譜線的光子輻射。巨大噴流是由雲頂向上傳播的電漿通道，起初可視為向上發展的藍色噴流(Blue jet)，但伴隨背景電場又激發出40到90公里高度的紅色精靈，可視為藍色噴流和紅色精靈的綜合體。但目前為止仍沒有任何文獻證明巨大噴流產生綠魅的現象。 為了證實這個猜想，找尋近三年內台灣巨大噴流紀錄並沒有巨大噴流產生綠魅的現象。通常N21P紅色譜線的生命週期為8s，時間遠短於一幀(0.33s)，但綠魅的現象中的557.7nm譜線的光子理論衰減時間約為0.7s。但2024年台灣拍攝最新的一個巨大噴流事件，在綠色譜線有明顯的時間延遲的效果從巨大噴流的下一幀的綠色通道畫面觀察到557.7nm綠色譜線的增強。 考慮實際觀測條件的影響，做了以下數值調整:我們發展以拍攝資料背景星場的視星等和溫度等資料，並考慮大氣影響，推算相機接收的絕對光子通量Rayleigh。先擬合出恆星灰階值(pixel value)與瑞利值之間的關係，從而推測出綠魅的瑞利值是否符合文獻和模型的數值。該事件的綠魅發生時為198.8±2.67Rayleigh，與文獻中的強度符合。 由於綠魅發生的原因與電漿流(streamer)有關，我們使用電漿化學模型(Plasma Chemistry Model)模擬高空閃電內部電漿流。藉由調整產生綠魅關鍵的因素，如電漿流的電場值以及背景O(3P)的密度(Density)，觀察它們對綠魅產生的激發態O(1S)以及對應產生557.7nm光子的發光速率(Emission rate)等。模型在557.7譜線光子的發光速率範圍在15~164photons∙〖cm〗^(-3) s^(-1)。在符合理論預測。 本研究證實了巨大噴流事件中的綠魅的現象，並提出以下兩點說明：(1) 觀測中得到的衰退時間(Decay lifetime)與文獻大致吻合，以及(2) 事件557.7譜線光子發光速率經換算位於模型的範圍內(16 to 67 photons∙〖cm〗^(-3) s^(-1))。本研究對於巨大噴流在夜間90公里高度氣暉層的影響提供直接的證據，並且也從電漿化學模型研究綠魅的產生條件。 ;The study aims to qualify whether the airglow enhancement called green ghost could be induced by the gigantic jet, The green ghost is a green aura that has been shown in the literature to occur after the production of one type of Transient Luminous Events (TLEs), the Red sprite, which is mainly caused by the depletion of O(1S) and the production of O(1D) and the emission of light in the 557.7 nm emission line (hυ5577). Gigantic jet is also one type of TLEs that propagate upward from the cloud to the top, and can develop up to 90 km, which is the altitude where the red sprite is generated. Due to the similarity of the mechanism and atmospheric environment, the structure at the top of the giant jet can be regarded as red sprite. However, there is no evidence in the literature of the green ghost emitted at the top of a gigantic jet so far. To confirm the conjecture, our team searched for a gigantic jet event and tried to extract the signal of the green ghost by morphology. The verification of extracted areas is green ghost or not includes calculating the photon flux by the stars on the image using several formulas and simulating the streamer on the mesosphere using plasma chemistry models. The photon flux of the green ghost for the event was derived to be 198.8±2.67 Rayleigh. The Plasma Chemistry Model is a model that can simulate the internal plasma streamer of Transient Luminous Events by adjusting the parameters to observe their densities and emission rates for photons emit by green ghost. The emission rates of hν(5577) is between 15 and 164 photons∙〖cm〗^(-3) s^(-1). The conclusion is that this gigantic jet is highly compatible with the production of the green ghost. The Decay lifetime is in general agreement with the literature, and the photon emission rate of the green ghost of the event has converted to be in the range of 16 to 67 photons∙〖cm〗^(-3) s^(-1), which is within the range of the plasma chemical model. This study represents a considerable advance in the scientific study of the coupling of the lower and upper atmosphere, such as the content of oxygen atoms (O) in the ionosphere, which is an important constituent of the ionosphere that affects radio reflection and atmospheric chemical reactions.
