Correlation Analysis of Lightning Whistlers Simultaneously Observed by Arase and Van Allen Probes

0508363 - ÚFA 2020 SG eng A - Abstract
Kasahara, Y. - Ogawa, Y. - Ikarashi, S. - Matsuda, S. - Miyoshi, Y. - Tsuchiya, F. - Kumamoto, A. - Hikishima, M. - Santolík, Ondřej - Kolmašová, Ivana - Hospodarsky, G. - Kletzing, C. - Colpitts, Ch. - Wygant, J. - Matsuoka, A.
Correlation Analysis of Lightning Whistlers Simultaneously Observed by Arase and Van Allen Probes.
Abstracts of AOGS : 16th Annual Meeting. Singapore: Asia Oceania Geosciences Society, 2019. ST29-D3-PM1-304-002.
[AOGS Annual Meeting /16./. 28.07.2019-02.08.2019, Singapore]
Institutional support: RVO:68378289
Keywords : magnetosphere * plasma waves * lightning whistlers * Van Allen Probes * Arase
OECD category: Fluids and plasma physics (including surface physics)
http://www.asiaoceania.org/aogs2019/public.asp?page=browse_abstract.htm

The PWE is an instrument on board the Arase (ERG) to measure plasma waves in the inner magnetosphere. Because the inclination of Arase is 31 degrees, which is larger than the ones of Van Allen Probes (~10 degrees), this orbital configuration provides the ability to explore not only the equatorial region but also the off-equatorial region in the inner magnetosphere. We intensively conducted burst waveform measurements collaborating with the EMFISIS and EFW on board the Van Allen Probes during more than 200 conjunction periods. We identified correlated wave spectra such as chorus and lightning whistlers among the collaborative observation data. We introduce two typical events when similar lightning whistlers were observed by the Arase and Van Allen Probes. One is a case where the Arase and RBSP-A were located along the geomagnetic field line at L ~3. We could recognize multiple whistlers followed by reflected ones by both satellites. Correlation study and direction finding analysis showed that the direct waves from source region propagated southward, and the waves were reflected northward and were again reflected back southward. Another event is a case where the Arase and RBSP-B were located near the equatorial plane at L ~2.75 but 10 degrees apart in longitude. Similar lightning whistlers were observed that suggests the lightning whistler propagated spreading at least 10 degrees in longitude. We also found that the wave was detected by the RBSP-B ~0.1s earlier than the Arase, and the dispersion derived from the RBSP-B data was smaller than the one from Arase. This fact suggests that the whistler detected by the Arase experienced longer propagation path or denser plasma density along the path. In the presentation, we discuss the propagation characteristics of lightning whistlers and plasma environments clarified from the correlation analyses.
Permanent Link: http://hdl.handle.net/11104/0299295