Effect of meteoric ions on ionospheric conductance at Jupiter

Yuki Nakamura (1, 2) , Koichiro Terada (1) , Chihiro Tao (3) , Naoki Terada (1) , Yasumasa Kasaba (1) , François Leblanc (2) , Hajime Kita (4) , Aoi Nakamizo (3) , Akimasa Yoshikawa (5, 6) , Shinichi Ohtani (7) , Fuminori Tsuchiya (1) , Masato Kagitani (1) , Takeshi Sakanoi (1) , Go Murakami (8) , Kazuo Yoshioka (9) , Tomoki Kimura (10) , Atsushi Yamazaki (8) , Ichiro Yoshikawa (9)

1 Graduate School of Science [Sendai]
2 HELIOS - LATMOS
3 Space Environment Laboratory [Kogonei]
4 Tohoku Institute of Technology
5 International Center for Space Weather Science and Education [Fukuoka]
6 Department of Earth and Planetary Sciences [Fukuoka]
7 APL - Johns Hopkins University Applied Physics Laboratory [Laurel, MD]
8 ISAS - Institute of Space and Astronautical Science
9 UTokyo - The University of Tokyo
10 Tokyo University of Science [Tokyo]

Ionospheric Pedersen and Hall conductances play significant roles in electromagnetic coupling between the planetary ionosphere and magnetosphere. Several observations and models have suggested the existence of meteoric ions with interplanetary origins in the lower part of Jupiter’s ionosphere; however, no models have considered the contributions of meteoric ions to ionospheric conductance. This study is designed to evaluate the contribution of meteoric ions to ionospheric conductance by developing an ionospheric model combining a meteoroid ablation model and a photochemical model. We find that the largest contribution to Pedersen and Hall conductivities occurs in the meteoric ion layer at altitudes of 350-600 km due to the large concentration of meteoric ions resulting from their long lifetimes of more than 100 Jovian days. Pedersen and Hall conductances are enhanced by factors of 3 and 10, respectively, in the middle- and low-latitude auroral regions when meteoric ions are included. The distribution of Pedersen and Hall conductances becomes axisymmetric in the middle- and low-latitude regions. Enhanced axisymmetric ionospheric conductance should impact magnetospheric plasma convection. The contribution of meteoric ions to the ionospheric conductance is expected to be important only on Jupiter in our solar system because of Jupiter’s intense magnetic and gravitational fields.

Domaines: Planète et Univers [physics]

Yuki Nakamura, Koichiro Terada, Chihiro Tao, Naoki Terada, Yasumasa Kasaba, et al.. Effect of meteoric ions on ionospheric conductance at Jupiter. Journal of Geophysical Research Space Physics, 2022, 127 (3), pp.e2022JA030312. ⟨10.1029/2022JA030312⟩. ⟨insu-03613864⟩