ELF/VLF Conjugate Observations Between the Ground and Van Allen Probes A

0477463 - ÚFA 2018 SG eng A - Abstract
Martinez-Calderon, C. - Shiokawa, K. - Miyoshi, Y. - Keika, K. - Ozaki, M. - Schofield, I. - Connors, M. - Kletzing, C. - Hanzelka, Miroslav - Santolík, Ondřej - Kurth, W.
ELF/VLF Conjugate Observations Between the Ground and Van Allen Probes A.
Abstracts of AOGS : 14th Annual Meeting. Singapore: Asia Oceania Geosciences Society, 2017. ST18-D4-AM2-329-008.
[AOGS Annual Meeting /14./. 06.08.2017-11.08.2017, Singapore]
Institutional support: RVO:68378289
Keywords : magnetosphere * VLF emissions * radiation belt electrons
Subject RIV: BL - Plasma and Gas Discharge Physics
http://www.meetmatt-svr3.net/aogs/aogs2017/mars2/pubViewAbs.asp?sMode=session&sId=137&submit=Browse+Abstracts

We report the simultaneous observations of quasi-periodical (QP) ELF/VLF emissions between the VLF receiver located at subauroral latitudes in Athabasca Canada (ATH, 54.7N, 246.7E, L=4.3) and the Van Allen Probes A (Radiation Belt Storm Probes (RBSP) A). The emissions showed similar spectral and temporal features making this a conjugate event. We based our study on a statistical database from 1 November 2012 to 31 October 2013 and compared a total of 347 emissions observed on the ground with observations made by RBSP A and/or B in the magnetosphere. On 25 February 2013, from 12:46 to 13:39 UT in the dawn sector (04–06 magnetic local time (MLT)), we observed in both locations, a QP emission centered at ~4 kHz, and an accompanying short pulse (SP) lasting less than a second at 4.8 kHz. RBSP-A wave data showed that both the QP and the SP were right-hand polarized with their Poynting vector earthward to the Northern Hemisphere. We used cross-correlation analysis to do the first time delay analysis of a conjugate ELF/VLF event between ground and space. We found +2 to +4 s (ATH saw the emission first) for the QP and −3 s (RBSP A first) for the SP. We performed a propagation study using backward ray tracing from 100 km above ATH to the geomagnetic equator and forward tracing from the equator to RBSP A. We used plasmaspheric density observed by the spacecraft to validate the most likely propagation path for the QP emission, consistent with the observed time delay.
Permanent Link: http://hdl.handle.net/11104/0273811