@article{a351e6410c5c49e8a0e5a77c08b245c6,
title = "Substorm-Associated Ionospheric Flow Fluctuations During the 27 March 2017 Magnetic Storm: SuperDARN-Arase Conjunction",
abstract = "Super Dual Auroral Radar Network (SuperDARN) observations show that ionospheric flow fluctuations of millihertz or lower-frequency range with horizontal velocities of a few hundred meters per second appeared in the subauroral to midlatitude region during a magnetic storm on 27 March 2017. A set of the radars have provided the first ever observations that the fluctuations propagate azimuthally both westward and eastward simultaneously, showing bifurcated phase propagation associated with substorm expansion. Concurrent observations near the conjugate site in the inner magnetosphere made by the Arase satellite provide evidence that multiple drifting clouds of electrons in the near-Earth equatorial plane were associated with the electric field fluctuations propagating eastward in the ionosphere. We interpret this event in terms of mesoscale pressure gradients carried by drifting ring current electrons that distort field lines one after another as they drift through the inner magnetosphere, causing eastward propagating ionospheric electric field fluctuations.",
keywords = "ERG, M-I coupling, SuperDARN, ULF wave, ring current electron, substorm injection",
author = "T. Hori and N. Nishitani and Shepherd, {S. G.} and Ruohoniemi, {J. M.} and M. Connors and M. Teramoto and S. Nakano and K. Seki and N. Takahashi and S. Kasahara and S. Yokota and T. Mitani and T. Takashima and N. Higashio and A. Matsuoka and K. Asamura and Y. Kazama and Wang, {S. Y.} and Tam, {S. W.Y.} and Chang, {T. F.} and Wang, {B. J.} and Y. Miyoshi and I. Shinohara",
note = "Funding Information: The authors acknowledge the use of SuperDARN data. SuperDARN is a collection of radars funded by national scientific funding agencies of Australia, Canada, China, France, Italy, Japan, Norway, South Africa, United Kingdom, and the United States. The common time FitACF data of SuperDARN are publicly available from the ERG Science Center (ERG-SC) data repository at https://ergsc.isee.nagoya-u.ac.jp/data/ergsc/ground/radar/sd/. The ERG-SC is operated as the joint research center for space science by JAXA/ISAS and ISEE, Nagoya University (https://ergsc.isee.nagoya-u.ac.jp/index.shtml.en). The SYM-H and AL indices were obtained from the World Data Center for Geomagnetism, Kyoto, Kyoto University at http://wdc.kugi.kyoto-u.ac.jp/index.html. The all-sky imager data for ATHA were provided in the supporting information, and the geomagnetic field data for ATHA, TPAS, and WHIT and THEMIS/ASI data were obtained from the THEMIS website at http://themis.ssl.berkeley.edu/index.shtml. ASI installation and operation at Athabasca were funded by the Canada Foundation for Innovation. We acknowledge NASA contract NAS5-02099 and V. Angelopoulos for use of data from the THEMIS mission. Specifically, we thank S. Mende and C. T. Russell for use of the THEMIS/GMAG data and NSF for support through grant AGS-1004814 and thank S. Mende and E. Donovan for use of the ASI data, the CSA for logistical support in fielding and data retrieval from the GBO stations, and NSF for support of GIMNAST through grant AGS-1004736. Science data of the ERG (Arase) satellite were obtained from the ERG-SC website (https://ergsc.isee.nagoya-u.ac.jp/index.shtml.en). The present study analyzed MGF v01_01 data, HEP v01_01 data, MEP-e v01_01 data, and MEP-i v01_01 data. The Arase satellite data will be publicly available via ERG-SC on a project-agreed schedule. Support for S. G. S. and the CVE and CVW SuperDARN radars is provided by National Science Foundation award AGS-1341925. Support for J. M. R. and the FHW and FHE SuperDARN radars is provided by NSF award AGS-1341918. Y. M. is supported by Japan Society for the Promotion of Science (JSPS), Grant-in-Aid for Scientific Research on Innovative Areas (grant 15H05815), Scientific Research (S; grant 15H05747), and Specially Promoted Research (grant 16H06286). Funding Information: The authors acknowledge the use of SuperDARN data. SuperDARN is a collection of radars funded by national scientific funding agencies of Australia, Canada, China, France, Italy, Japan, Norway, South Africa, United Kingdom, and the United States. The common time FitACF data of SuperDARN are publicly available from the ERG Science Center (ERG-SC) data repository at https://ergsc.isee.nagoya-u.ac.jp/data/ ergsc/ground/radar/sd/. The ERG-SC is operated as the joint research center for space science by JAXA/ISAS and ISEE, Nagoya University (https://ergsc.isee. nagoya-u.ac.jp/index.shtml.en). The SYM-H and AL indices were obtained from the World Data Center for Geomagnetism, Kyoto, Kyoto University at http://wdc.kugi.kyoto-u.ac.jp/index. html. The all-sky imager data for ATHA were provided in the supporting information, and the geomagnetic field data for ATHA, TPAS, and WHIT and THEMIS/ASI data were obtained from the THEMIS website at http://themis.ssl. berkeley.edu/index.shtml. ASI installation and operation at Athabasca were funded by the Canada Foundation for Innovation. We acknowledge NASA contract NAS5-02099 and V. Angelopoulos for use of data from the THEMIS mission. Specifically, we thank S. Mende and C. T. Russell for use of the THEMIS/GMAG data and NSF for support through grant AGS-1004814 and thank S. Mende and E. Donovan for use of the ASI data, the CSA for logistical support in fielding and data retrieval from the GBO stations, and NSF for support of GIMNAST through grant AGS-1004736. Science data of the ERG (Arase) satellite were obtained from the ERG-SC website (https://ergsc.isee. nagoya-u.ac.jp/index.shtml.en). The present study analyzed MGF v01_01 data, HEP v01_01 data, MEP-e v01_01 data, and MEP-i v01_01 data. The Arase satellite data will be publicly available via ERG-SC on a project-agreed schedule. Support for S. G. S. and the CVE and CVW SuperDARN radars is provided by National Science Foundation award AGS-1341925. Support for J. M. R. and the FHW and FHE SuperDARN radars is provided by NSF award AGS-1341918. Y. M. is supported by Japan Society for the Promotion of Science (JSPS), Grant-in-Aid for Scientific Research on Innovative Areas (grant 15H05815), Scientific Research (S; grant 15H05747), and Specially Promoted Research (grant 16H06286). Publisher Copyright: {\textcopyright}2018. American Geophysical Union. All Rights Reserved.",
year = "2018",
month = sep,
day = "28",
doi = "10.1029/2018GL079777",
language = "English",
volume = "45",
pages = "9441--9449",
number = "18",
}