[P-EM13] Dynamics of the Inner Magnetospheric System

[PEM13-08] Variation of the altitude of auroral emission during a substorm cycle: Stereoscopic optical observations during the LAMP rocket experiment

*Keisuke Hosokawa¹, Yoshizumi Miyoshi², Matthew Geoff Mcharg³, Vincent Ledvina⁴, Donald Hampton⁴, Mykhaylo Shumko⁵, Kazushi Asamura⁶, Takeshi Sakanoi⁷, Takefumi Mitani⁶, Taku Namekawa⁶, Masahito Nose², Yasunobu Ogawa⁸, Marc Lessard⁹, Alexa Jean Halford⁵, Allison Jaynes¹⁰ (1.University of Electro-Communications, 2.ISEE, Nagoya University, 3.US Airforce Academy, 4.University of Alaska Fairbanks, 5.NASA/GSFC, 6.ISAS/JAXA, 7.Tohoku University, 8.National Institue of Polar Research, 9.University of New Hampshire, 10.University of Iowa)

It has widely been known that the energy of precipitating electrons causing pulsating aurorae (PsA) is higher than that of typical discrete aurorae. The tail of the energy spectra of PsA sometimes extends to a few tens/hundreds of keV. Such sub-relativistic electron precipitations can be explained by the propagation of chorus waves, which is the agent causing the electron precipitation through the wave-particle interaction, towards higher latitudes (e.g., Miyoshi et al., 2020). To understand the simultaneous precipitation of higher energy electrons during PsA, the LAMP sounding rocket was launched from the Poker Flat Research Range in Alaska on March 5, 2022. During the launch window of the rocket, three high-speed all-sky cameras were operative at three stations immediately below the trajectory of the rocket: Poker Flat, Venetie, and Fort Yukon. The all-sky cameras captured all-sky images with a temporal resolution of 100 Hz (80 Hz for the Fort Yukon case). By using these images, we are able to visualize the spatiotemporal variation of PsA during the entire flight of the rocket. Not only that, it is possible to estimate the altitude of aurora in regions where the fields-of-view of multiple cameras overlap. For example, the separation between Poker Flat and Venetie is only ~100 km; thus, the central altitude of the PsA emission can be estimated in a large area between these two observation sites. When deriving the altitude of PsA emission we have simply applied a cross-correlation analysis to the data obtained from two observation sites. In the presentation, we discuss the temporal variation and spatial distribution of the altitude of PsA emission in comparison with data from particle sensors onboard the rocket.