[P-PS04] Mercury Science and Exploration

[PPS04-04] Spatial distribution of whistler-mode waves in Mercury's magnetosphere during BepiColombo flybys

★Invited Papers

*Mitsunori Ozaki¹, Satoshi Yagitani¹, Yasumasa Kasaba², Yoshiya Kasahara¹, Shoya Matsuda¹, Yoshiharu Omura³, Mitsuru Hikishima⁴, Fouad Sahraoui⁵, Laurent Mirioni⁵, Gérard Chanteur⁵, Satoshi Kurita³, Team PWI (1.Kanazawa Univ., 2.Tohoku Univ., 3.Kyoto Univ., 4.MagneDesign Corporation, 5.Laboratoire de Physique des Plasmas)

Keywords:Mercury's magnetosphere, Plasma wave

Whistler-mode waves in Mercury's magnetosphere have been successfully identified by PWI (plasma wave investigation) during the BepiColombo/Mio flybys. The first, second, and third flybys of Mio spacecraft passed from the night to dawn sides. The 4th flyby trajectory passed from north to south direction near the dawn side. The 5th flyby trajectory was far from Mercury's magnetosphere, so PWI did not detect clear whistler-mode wave activity. Finally, the last 6th flyby trajectory passed from south to north in the mid-night region. These various flyby trajectories were suitable for characterizing the spatial activities of whistler-mode waves before Mercury orbit insertion in 2026. In this presentation, we will present the spatial distribution of Mercury's whistler-mode waves during all the flybys. We will also compare the observed spatial distribution and possible generation regions inferred from nonlinear wave growth theory.