Cause and Effects of Relativistic Electron Precipitation at CALET onboard ISS (Invited talk)
Date:
R. Kataoka (1), A. Bruno (2,3), L. W. Blum (4), G. A. de Nolfo (2), S. Nakahira (5), S. Miyake (6), and S. Torii (7)
(1) National Institute of Polar Research
(2) NASA/GSFC, USA
(3) Catholic University of America, USA
(4) University of Colorado Boulder, USA
(5) JAXA/ISAS, Japan
(6) Ibaraki College, Japan
(7) Waseda University, Japan
Relativistic electron precipitation (REP) events observed by CALET-CHD instrument at the International Space Station (ISS, orbiting ~400 km altitude) have been interpreted as the manifestation of the wave-particle interaction between electromagnetic ion cyclotron (EMIC) waves and trapped MeV electrons (Kataoka et al., 2016). This presentation will address following questions by reviewing recent publications:
Q1: Exposure dose during extravehicular activities on the ISS?
Q2: Effects on the disappearance of radiation belt MeV electrons?
Q3: EMIC waves a dominant cause of REP events?
A1: From the quantitative evaluation of the exposure dose during EVA on the ISS, using the MeV electron flux data during REP events, there is no need to be overly concerned (Ueno et al., 2019).
A2: Conjunction observations with the Van Allen Probe suggest that a major MeV electron drop-out event was caused by both REP events and the magnetopause shadowing effect at different positions (Bruno et al., 2021).
A3: The plasma waves that caused the REP events were investigated by the conjunction observations with the Arase satellite, and the contribution of whistler mode waves was also clearly identified (Kataoka et al., 2020).
CALET-CHD data are available from ISAS-DARTS. A new web interface for viewing the data is also available here.
References
Kataoka, R., Y. Asaoka, S. Torii, T. Terasawa, S. Ozawa, T. Tamura, Y. Shimizu, Y. Akaike, and M. Mori (2016), Relativistic electron precipitation at International Space Station: Space weather monitoring by Calorimetric Electron Telescope, Geophys. Res. Lett., 43, 4119-4125, https://doi.org/10.1002/2016GL068930.
Kataoka R., et al. (2020), Plasma waves causing relativistic electron precipitation events at International Space Station: Lessons from conjunction observations with Arase satellite, Journal of Geophysical Research: Space Physics, 125, e2020JA027875. https://doi.org/10.1029/2020JA027875.
Ueno H., S. Nakahira, R. Kataoka, et al. (2019), Radiation dose during relativistic electron precipitation events at the International Space Station, Space Weather, 17, https://doi.org/10.1029/2019SW002280.
Bruno, A., Blum, L. W., de Nolfo, G. A., Kataoka, R., Torii, S., Greeley, A. D., et al. (2022). EMIC-wave driven electron precipitation observed by CALET on the International Space Station. Geophysical Research Letters, 49, e2021GL097529. https://doi.org/10.1029/2021GL097529