[P-EM12] Space Weather and Space Climate

[PEM12-04] Different flux evolutions of relativistic electrons of the outer belt associated with high-speed coronal hole streams; Arase and Van Allen Probes observations

*Yoshizumi Miyoshi¹, Satoshi Kurita¹, Ryuho Kataoka², Shinji Saito¹, Vania Jordanova³, Iku Shinohara⁴, Takefumi Mitani⁴, Takeshi Takashima⁴, Nana Higashio⁴, Satoshi Kasahara⁵, Shoichiro Yokota⁶, Tomoaki Hori¹, Kunihiro Keika⁵, Yoshiya Kasahara⁷, Shoya Matsuda⁴, Atsushi Kumamoto⁸, Fuminori Tsuchiya⁸, Masafumi Shoji¹, Ayako Matsuoka¹, Mariko Teramoto¹, Harlan Spence⁹, Geoff Reeves³, Daniel Baker¹⁰ (1.Institute for Space-Earth Environmental Research, Nagoya University, 2.NIPR, 3.Los Alamos National Laboratory, 4.JAXA, 5.University of Tokyo, 6.Osaka University, 7.Kanazawa University, 8.Tohoku University, 9.University of New Hampshire, 10.University of Colorado)

Keywords:radiation belts, Arase, Sun-Earth Connection

Relativistic and ultra-relativistic electrons increase largely during the high-speed coronal hole streams, and the enhanced flux levels are controlled by the solar wind speed and the prolonged southward IMF. Such flux enhancements associated with high-speed streams have been observed by Arase/HEP and XEP instruments as well as Van Allen Probes/MagEIS and REPT. Some coronal hole streams produce large flux enhancement of both relativistic and ultra-relativistic electrons, while other coronal holes produce large flux enhancement of relativistic electrons (~2 MeV) but do not produce enhancement of ultra-relativistic electrons. In this presentation, we will show evolutions of the energy spectrum of relativistic electrons during the coronal hole streams and discuss how evolutions of the energy spectrum are related to chorus wave activities that are derived from Arase/PWE measurements and the proxy data from the low-altitude satellite data.