Journal article
Variation of the Altitude of Auroral Emission During a Substorm Cycle: Stereoscopic Optical Observations During the LAMP Rocket Experiment
Journal of geophysical research. Space physics, Vol.129(11), e2024JA033036
11/2024
DOI: 10.1029/2024JA033036
Abstract
Abstract We estimated the altitude of aurora by combining data from all‐sky cameras at multiple places which were obtained during the LAMP sounding rocket experiment in Alaska on 5 March 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). The method of altitude determination is based on analyses of time‐series of the optical intensity obtained from the all‐sky cameras in Venetie and Poker Flat covering the downrange area of the rocket trajectory. The estimated altitude of pulsating aurora during the rocket experiment was found to be consistent with that derived from the in‐situ observation of precipitating electrons with a model of optical emission, which confirms the feasibility of deriving the emission altitude through correlation analyses using time‐series. The estimated altitude of aurora decreased after the expansion onset of the substorm and stayed slightly below 100 km during the interval of pulsating aurora in the recovery phase. In particular, prompt and brief lowering of the auroral emission, well down to around 90 km, was detected during a transition of auroral form from discrete to diffuse which occurred ∼10 min after the onset. This result implies an existence of a process causing harder electron precipitation operative soon after the start of the expansion phase of auroral substorm.
Plain Language Summary To determine the altitude of the auroras, we analyzed the brightness of the auroras over time using the images obtained during the LAMP sounding rocket experiment in Alaska on 5 March 2022. The altitude of the pulsating auroras observed during the experiment matched the altitude estimated from the direct observation of electrons precipitating into the atmosphere, using a model of optical emissions. This confirms that the method of deriving auroral height through time‐series correlation analysis is effective. The height of the auroras decreased after the substorm began and remained just below 100 km during the period of pulsating auroras in the recovery phase. Specifically, a rapid and brief decrease in auroral height to around 90 km was observed about 10 min after the substorm started, when the aurora changed from discrete to diffuse. This indicates a process that causes more intense electron precipitation shortly after the substorm expansion phase begins.
Key Points Altitude of pulsating aurora emission was estimated by using triangulation of all‐sky camera data from multiple stations in Alaska Altitude of pulsating diffuse aurora was lower than discrete aurora Decrease of the emission altitude occurred ∼10 min after the substorm onset
Details
- Title: Subtitle
- Variation of the Altitude of Auroral Emission During a Substorm Cycle: Stereoscopic Optical Observations During the LAMP Rocket Experiment
- Creators
- K. Hosokawa - University of Electro-CommunicationsY. Miyoshi - Nagoya UniversityM. Mcharg - United States Air Force AcademyV. Ledvina - University of Alaska FairbanksD. Hampton - University of Alaska FairbanksM. Lessard - University of New Hampshire at ManchesterM. Shumko - Johns Hopkins University Applied Physics LaboratoryK. Asamura - Japan Aerospace Exploration AgencyT. Sakanoi - Tohoku UniversityT. Mitani - Japan Aerospace Exploration AgencyT. Namekawa - Japan Aerospace Exploration AgencyM. Nosé - Nagoya City UniversityY. Ogawa - National Institute of Polar ResearchA. Jaynes - University of IowaA. Halford - Goddard Space Flight Center
- Resource Type
- Journal article
- Publication Details
- Journal of geophysical research. Space physics, Vol.129(11), e2024JA033036
- Publisher
- AMER GEOPHYSICAL UNION
- DOI
- 10.1029/2024JA033036
- ISSN
- 2169-9380
- eISSN
- 2169-9402
- Grant note
- Japan Society for the Promotion of ScienceNASA Wallops Flight Facility (WFF)Poker Flat Research Range (PFRR)University of Alaska Fairbanks (UAF): 15H05747, 18KK0100, 20H01959, 21H04526, 22H00173, 22KK0046, 23H01229 Japan Society for the Promotion of Science (JSPS), KAKENHI: 80NSSC18K0950, 80NSSC18K0952, 80NSSC18K0965, 0040-0006-0208_v01 NASA
We are grateful for the support of NASA Wallops Flight Facility (WFF) and Poker Flat Research Range (PFRR). The operation of the EMCCD ASIs in Poker Flat Research Range, Venetie and Fort Yukon, Alaska was supported by the University of Alaska Fairbanks (UAF). This work was supported by the Japan Society for the Promotion of Science (JSPS), KAKENHI (15H05747, 18KK0100, 20H01959, 21H04526, 22H00173, 22KK0046, and 23H01229). US-based LAMP team members were supported by NASA Grants (80NSSC18K0950, 80NSSC18K0952, and 80NSSC18K0965). This work was carried out by the joint research program of the Institute for Space-Earth Environmental Research (ISEE), Nagoya University. The EMCCD all-sky camera data are accessible at the following DOI, 10.34515/DATA.GND-0040-0006-0208_v01.
- Language
- English
- Date published
- 11/2024
- Academic Unit
- University College Courses; Physics and Astronomy
- Record Identifier
- 9984747060202771
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