Spectroscopic Diagnostic of Halos and Elves Detected From Space‐Based Photometers

Abstract

In this work, we develop two spectroscopic diagnostic methods to derive the peak reduced electric field in transient luminous events (TLEs) from their optical signals. These methods could be used to analyze the optical signature of TLEs reported by spacecraft such as Atmosphere‐Space Interactions Monitor (European Space Agency) and the future Tool for the Analysis of RAdiations from lightNIngs and Sprites (Centre National d'Études Spatiales). As a first validation of these methods, we apply them to the predicted (synthetic) optical signatures of halos and elves, two types of TLEs, obtained from electrodynamical models. This procedure allows us to compare the inferred value of the peak reduced electric field with the value computed by halo and elve models. Afterward, we apply both methods to the analysis of optical signatures of elves and halos reported by Global LIghtning and sprite MeasurementS (Japan Aerospace Exploration Agency) and Imager of Sprites and Upper Atmospheric Lightning (National Space Organization) spacecraft, respectively. We conclude that the best emission ratios to estimate the maximum reduced electric field in halos and elves are the ratio of the second positive system of N2 to first negative system (FNS) of N 2+, the first positive system of N2 to FNS of N 2+ and the Lyman‐Birge‐Hopfield band of N2 to FNS of N 2+. In the case of reduced electric fields below 150 Td, we found that the ratio of the second positive system of N2 to first positive system of N2 can also be used to reasonably estimate the value of the field. Finally, we show that the reported optical signals from elves can be treated following an inversion method in order to estimate some of the characteristics of the parent lightning.

Global Occurrence and Chemical Impact of Stratospheric Blue Jets Modeled With WACCM4

“…Other types of TLEs, known as halos and elves, can also be produced in the upper atmosphere at altitudes greater than 70 and 80 km. Both halos and sprites can have a duration of several milliseconds (Barrington‐Leigh et al, ; Bering, Benbrook, et al, ; Bering et al, ; Bering, Bhusal, et al, ; Frey et al, ; Gordillo‐Vázquez, ; Luque & Gordillo‐Vázquez, ; Lyons et al, ; Moudry et al, ; Sentman & Wescott, ; Sentman et al, ; Wescott, Stenbaek‐Nielsen, et al, ), while elves have a duration of less than 1 ms (Gordillo‐Vázquez et al, ; Inan et al, , ; Kuo et al, ; Marshall et al, ; Moudry et al, ; Pérez‐Invernón, Luque, & Gordillo‐Vázquez, ; Pérez‐Invernón, Luque, Gordillo‐Vazquez, Sato, et al, ; Taranenko et al, ; van der Velde & Montanyá, ).…”

“…Both halos and sprites can have a duration of several milliseconds (Barrington-Leigh et al, 2001; Journal of Geophysical Research: Atmospheres 10.102910. /2018JD029593 et al, 2002Frey et al, 2007;Gordillo-Vázquez, 2008;Luque & Gordillo-Vázquez, 2011;Lyons et al, 2000;Moudry et al, 2003;Sentman et al, 2008;, while elves have a duration of less than 1 ms Inan et al, 1997Inan et al, , 1991Kuo et al, 2007;Marshall et al, 2010;Moudry et al, 2003;Pérez-Invernón, Luque, & Gordillo-Vázquez, 2018;Pérez-Invernón, Luque, Gordillo-Vazquez, Sato, et al, 2018;Taranenko et al, 1993;van der Velde & Montanyá, 2016).…”

Optical Spectra of Small‐Scale Sprite Features Observed at 10,000 fps

“…More recently, Gordillo-Vázquez et al (2018) used sprite spectra with 0.24 nm resolution to derive mesospheric temperatures and found no measurable heating of the neutral atmosphere. Finally, modeling by Pérez-Invernón et al (2018) indicate that the ratio of 1PN2 to 2PN2, the emissions that dominate the 10,000 fps observations presented in this paper, does not vary much for reduced electric fields above~200 Td but is adequate at lower fields. They suggest that a better ratio might be 1PN2 or 2PN2 to 1NN2+, as suggested earlier by Pasko (2007Pasko ( , 2010.…”

“…Another possibility would be to avoid using the red 1PN2 band emissions which are most affected by quenching. Pasko (2007) and Pérez-Invernón et al (2018) have suggested that 2PN2 and 1NN2+ may be used. However, these optical bands are both in the blue and are difficult to separate in slitless spectroscopic data.…”

The Contribution of Sprite Streamers to the Chemical Composition of the Mesosphere‐Lower Thermosphere

“…The transient behavior of the N 2 (a 1 Π g , v ) VDF is influenced by the radiative decay of the electronically excited N 2 (w 1 Δ u , v ) to N 2 (a 1 Π g , v = 0)—with a characteristic time of 0.6 ms (Gilmore, 1992)—within the streamer channel. This cascading process breaks the assumption of a constant VDF of the N 2 (a 1 Π g , v ) levels, which is required to calculate the contribution of the LBH into the photometer band and to estimate the altitude of the streamer head (Pérez‐Invernón et al., 2018).…”