A Ground‐Based Instrument Suite for Integrated High‐Time Resolution Measurements of Pulsating Aurora With Arase

Abstract

A specialized ground‐based system has been developed for simultaneous observations of pulsating aurora (PsA) and related magnetospheric phenomena with the Arase satellite. The instrument suite is composed of (a) six 100 Hz sampling high‐speed all‐sky imagers (ASIs), (b) two 10 Hz sampling monochromatic ASIs observing 427.8 and 844.6 nm auroral emissions, (c) a 20 Hz sampling fluxgate magnetometer. The 100 Hz ASIs were deployed in four stations in Scandinavia and two stations in Alaska, which have been used for capturing the main pulsations and quasi 3 Hz internal modulations of PsA at the same time. The 10 Hz sampling monochromatic ASIs have been operative in Tromsø, Norway with the 20 Hz sampling magnetometer. Combination of these multiple instruments with the European Incoherent SCATter (EISCAT) radar enables us to detect the low‐altitude ionization due to energetic electron precipitation during PsA and further to reveal the ionospheric electrodynamics behind PsA. Since the launch of the Arase satellite, the data from these instruments have been examined in comparison with the wave and particle data from the satellite in the magnetosphere. In the future, the system can be utilized not only for studies of PsA but also for other classes of aurora in close collaboration with the planned EISCAT_3D project.

Thermospheric Wind Response to March 2023 Storm: Largest Wind Ever Observed With a Fabry‐Perot Interferometer in Tromsø, Norway Since 2009

“…An optical filter (RG665) was mounted on the EMCCD camera to mainly measure the N 2 first positive (1PG) emissions, in which the peak emission height may be approximately 100 km. The original time resolution was 0.01 s, and post-analysis was performed to provide images with a time resolution of 1 s. More detailed information on the camera system can be found in Hosokawa et al (2023).…”

“…The original time resolution was 0.01 s, and post‐analysis was performed to provide images with a time resolution of 1 s. More detailed information on the camera system can be found in Hosokawa et al. (2023).…”

“…A conceptual drawing illustrated by Hernandez et al. (1982; Figure 7 in their publication) may be helpful in tracing the wind flow starting from the auroral oval. Molecular‐rich air transportation along the wind surge reduces the O/N 2 ratio (Cai et al., 2023; Immel et al., 2001; Miller et al., 1984; Strickland et al., 2001; Yu et al., 2022; Zhang et al., 2004), which depresses the ionospheric plasma density via the dissociative recombination process, that is, negative ionospheric storm (Strickland et al., 2001).…”

An Implication of Detecting the Internal Modulation in a Pulsating Aurora: A Conjugate Observation by the Arase Satellite and All‐Sky Imagers

“…For the optical observation of PsA, we used electron‐multiplying CCD (EMCCD) all‐sky cameras installed at Sodankylä (67.37°N, 26.63°E) in Finland and Tjautjas (67.28°N, 20.72°E) in Sweden, as described in Hosokawa, Oyama, et al. (2020). The all‐sky cameras capture auroral images with 256 × 256 pixels at a sampling rate of 100 Hz.…”

Correspondence of Pi2 Pulsations, Aurora Luminosity, and Plasma Flux Fluctuation Near a Substorm Brightening Aurora: Arase Observations

“…For the ground‐based observation, we used an electron‐multiplying charge‐coupled device (EMCCD) camera that was operated at Gakona, Alaska (Hosokawa et al., 2021). This EMCCD camera is part of study of dynamical variation of particles and waves in the inner magnetosphere using ground‐based network observations (PWING project) (Shiokawa et al., 2017).…”