JpGU-AGU Joint Meeting 2020

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[E] Oral

P (Space and Planetary Sciences ) » P-EM Solar-Terrestrial Sciences, Space Electromagnetism & Space Environment

[P-EM13] Dynamics of Magnetosphere and Ionosphere

convener:Aoi Nakamizo(Applied Electromagnetic Research Institute, National Institute of Information and Communications Technology), Mitsunori Ozaki(Faculty of Electrical and Computer Engineering, Institute of Science and Engineering, Kanazawa University), Akiko Fujimoto(Kyushu Institute of Technology), Yuka Sato(Nippon Institute of Technology)

[PEM13-16] Statistical characteristics of the duskside mesoscale field-aligned currents without accompanying the large-scale Region 1 current

*Yoshihiro Yokoyama1, Satoshi Taguchi1, Toshihiko Iyemori2, Keisuke Hosokawa3 (1.Department of Geophysics, Graduate School of Science, Kyoto University, 2.Kyoto University, 3. Department of Communication Engineering and Informatics, University of Electro-Communications)

Keywords:mess scale field-aligned current, northward IMF condition, Swarm satellite

During prolonged quiet times the large-scale Region 1 current nearly diminishes except for its near-noon part, and irregular magnetic perturbations exist at latitudes where the Region 1 current disappeared. Our recent event study has shown that the irregular magnetic perturbations on the duskside are a result of highly structured quasi-static field-aligned currents whose typical latitudinal size is 20–30 km, and that those mesoscale currents in the duskside auroral oval are the phenomena that are pertinent to the magnetosphere for a northward IMF condition, not a simple remnant of the typical Region 1. In the present study, in order to clarify detailed characteristics of the mesoscale field-aligned currents without accompanying the large-scale Region 1 we examined large amounts of data obtained by Swarm satellites during three years, i.e., from January 2014 to December 2016. How the occurrence of those mesoscale field-aligned currents is controlled by solar illumination of the ionosphere and upstream solar wind parameters other than the northward component of IMF is presented.