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Modeling studies of NO‐ γ emissions of sprites
Author(s) -
Liu Ningyu,
Pasko Victor P.
Publication year - 2007
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2007gl030352
Subject(s) - sprite (computer graphics) , metastability , atmospheric sciences , excited state , environmental science , meteorology , atmospheric electricity , altitude (triangle) , airglow , effects of high altitude on humans , physics , atomic physics , electric field , geometry , mathematics , quantum mechanics , computer science , computer vision
Motivated by observations of NO‐ γ emissions: NO( A 2 Σ + ) → NO( X 2 Π r ) + hν from streamer discharges in laboratory experiments, we develop a model to study these emissions associated with streamer discharges in air at different pressures. The modeling results indicate that the NO( A 2 Σ + ) species in sprite streamers at 70 km altitude are mostly produced by interaction of N 2 ( A 3 Σ u + ) metastable species with high‐density ambient NO( X 2 Π r ) molecules. Analysis of the production and loss mechanisms for the upper excited states leading to NO‐ γ and N 2 LBH emissions demonstrates that the total intensity of NO‐ γ emissions associated with sprites is substantially weaker than that of the N 2 LBH emissions. The same conclusion can be drawn for elves following similar analysis. It is demonstrated that the presented modeling approach and analysis are consistent with prior knowledge on NO‐ γ emissions from aurora, indicating that to observe the NO‐ γ emissions from aurora, the ambient NO density must be highly enhanced in the auroral region.