Effect of Meteoric Ions on Ionospheric Conductance at Jupiter
Effect of Meteoric Ions on Ionospheric Conductance at Jupiter
复制标题
流星离子对木星电离层电导的影响
DOI：
10.1029/2022ja030312
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
Yamazaki Atsushi
中科院分区：
文献类型：
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作者：
Nakamura Yuki;Terada Koichiro;Tao Chihiro;Terada Naoki;Kasaba Yasumasa;Leblanc Fran?ois;Kita Hajime;Nakamizo Aoi;Yoshikawa Akimasa;Ohtani Shinichi;Tsuchiya Fuminori;Kagitani Masato;Sakanoi Takeshi;Murakami Go;Yoshioka Kazuo;Kimura Tomoki;Yamazaki Atsushi
电离层Pedersen和Hall电导在行星电离层和磁层之间的电磁耦合中起着重要作用。一些观测和模型表明，在木星电离层下部存在行星际起源的流星离子;然而，没有模型考虑流星离子对电离层电导的贡献。本研究的目的是通过建立一个结合流星体消融模型和光化学模型的电离层模型来评估流星体离子对电离层电导的贡献。我们发现，对佩德森和霍尔电导率的最大贡献发生在海拔350-600公里的流星离子层中，这是因为流星离子的寿命超过100个木星日，因此浓度很高。在中低纬度和极光区，当包括流星离子时，彼得森和霍尔电导分别增强了3倍和10倍。在中低纬度地区，佩德森电导和霍尔电导的分布呈轴对称。增强的轴对称电离层电导应影响磁层等离子体对流。流星离子对电离层电导的贡献预计只在我们太阳系的木星上重要，因为木星有强烈的磁场和引力场。
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 and 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.