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The Boltzmann Vibrational Temperature of N 2 (B 3 Π g ) Derived From ISUAL Imager Multiband Measurements of Transient Luminous Events
Author(s) -
Kuo ChengLing,
Chou JungKuang,
Wu YenJung,
Williams Earle,
Chen Alfred B.C.,
Su HanTzong,
Hsu RueRon,
Lee LouChuang
Publication year - 2019
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1029/2019ja027311
Subject(s) - brightness , physics , analytical chemistry (journal) , boltzmann constant , atomic physics , chemistry , optics , chromatography , thermodynamics
One of the main challenges for the observation of a transient luminous event (TLE) is to observe TLEs in different emission bands. Here, we show TLEs recorded using the ISUAL 427.8 nm, 630 nm, N 2 1P (623–750 nm) and 762‐nm‐filtered imager, and we analyze the 630‐nm‐filtered, N 2 1P‐filtered, and 762‐nm‐filtered images of TLEs for estimating the N 2 (B 3 Π g ) Boltzmann vibrational temperature in comparison with the theoretical N 2 1P spectrum. For ISUAL recorded sprites, the average brightness of N 2 1P (I 1p ), 762 nm (I 762 ), and 630 nm (I 630 ) emission was 2.3, 0.6, and 0.02 MR. The N 2 (B 3 Π g ) vibrational temperatures ( T v ) was estimated to be 2800 K, 3200 K, and 4300 K for multiband emission ratios of I 630 /I 1p , I 630 /I 762 , and I 762 /I 1p . For observed elves, the average brightness I 1p , I 762 , and I 630 were 170, 50, and 3 kR. The estimated T v values were 3700 K, 3700 K, and 3800 K for ratios I 630 /I 1p , I 630 /I 762 , and I 762 /I 1p . For observed gigantic jets, the derived T v values were 3000–5000 K for a ratio I 762 /I 1p . Through N 2 (B 3 Π g ) T v analyses from emission ratios of ISUAL multiband observation, we derived the N 2 (B 3 Π g ) vibrational temperature that ranges between 3000 and 5000 K or higher in TLEs. Accuracy and variations of derived N 2 (B 3 Π g ) T v are also discussed while relative population of vibrational levels in the Boltzmann equilibrium are also compared with past spectra observation.