Purple Auroral Rays and Global Pc1 Pulsations Observed at the CIR-Associated Solar Wind Density Enhancement on 21 March 2017

K. Shiokawa, M. Ozaki, A. Kadokura, Y. Endo, T. Sakanoi, S. Kurita, Y. Miyoshi, S. I. Oyama, M. Connors, I. Schofield, J. M. Ruohoniemi, M. Nośe, T. Nagatsuma, K. Sakaguchi, D. G. Baishev, A. Pashinin, R. Rakhmatulin, B. Shevtsov, I. Poddelsky, M. EngebretsonTero Raita, Y. M. Tanaka, M. Shinohara, M. Teramoto, R. Nomura, A. Fujimoto, A. Matsuoka, N. Higashio, T. Takashima, I. Shinohara, Jay M. Albert

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

Abstract

This paper reports two unique auroral features: postmidnight purple auroral rays and global Pc1 geomagnetic pulsations, observed before the onset of the corotating interaction region (CIR) storm of 21 March 2017, at the beginning of the first campaign of the new Particles and Waves in the Inner magnetosphere using Ground-based network observation (PWING) longitudinal ground network with the Arase satellite. The purple auroral rays were observed from ~0315 to 0430 UT (~03–04 magnetic local time) in the northeastern sky at Husafell, Iceland (magnetic latitude: 64.9°N). We newly propose that the entry of high-density CIR plasma into the magnetotail created purple auroral rays in the sunlit ionosphere. Pc1 geomagnetic pulsations at frequencies of 0–0.5 Hz were observed after ~00 UT over a wide local time range, of 13 hr, from midnight to afternoon sectors at subauroral latitudes associated with CIR arrival. These results indicate preconditioning of the magnetosphere due to crossing of a CIR.

Original languageEnglish
Pages (from-to)10,819-10,828
JournalGeophysical Research Letters
Volume45
Issue number20
DOIs
Publication statusPublished - 2018 Oct 28

Keywords

  • Arase satellite
  • CIR storm
  • EMIC wave
  • PWING project
  • Pc1 pulsation
  • purple aurora

ASJC Scopus subject areas

  • Geophysics
  • Earth and Planetary Sciences(all)

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