MESSENGER observations of Mercury's planetary ion escape rates and their dependence on true anomaly angle

التفاصيل البيبلوغرافية
العنوان: MESSENGER observations of Mercury's planetary ion escape rates and their dependence on true anomaly angle
المؤلفون: Sun, Weijie, Dewey, Ryan M., Jia, Xianzhe, Raines, Jim M., Slavin, James A., Chen, Yuxi, Phan, Tai, Poh, Gangkai, Xu, Shaosui, Milillo, Anna, Lillis, Robert, Saito, Yoshifumi, Livi, Stefano, Orsini, Stefano
المصدر: Geophysical Research Letters, 51, e2023GL107689 (2024)
سنة النشر: 2024
المجموعة: Astrophysics
Physics (Other)
مصطلحات موضوعية: Physics - Space Physics, Astrophysics - Earth and Planetary Astrophysics, Physics - Plasma Physics
الوصف: This study investigates the escape of Mercury's sodium-group ions (Na+-group, including ions with m/q from 21 to 30 amu/e) and their dependence on true anomaly angle (TAA), i.e., Mercury's orbital phase around the Sun, using measurements from MESSENGER. The measurements are categorized into solar wind, magnetosheath, and magnetosphere, and further divided into four TAA intervals. Na+-group ions form escape plumes in the solar wind and magnetosheath, with higher fluxes along the solar wind's motional electric field. The total escape rates vary from 0.2 to 1 times 10^{25} atoms/s with the magnetosheath being the main escaping region. These rates exhibit a TAA dependence, peaking near the perihelion and similar during Mercury's remaining orbit. Despite Mercury's tenuous exosphere, Na+-group ions escape rate is comparable to other inner planets. This can be attributed to several processes, including that Na+-group ions may include several ion species, efficient photoionization frequency for elements within Na+-group, etc.
Comment: 21 pages, 4 figures
نوع الوثيقة: Working Paper
DOI: 10.1029/2023GL107689
URL الوصول: http://arxiv.org/abs/2404.13264
رقم الأكسشن: edsarx.2404.13264
قاعدة البيانات: arXiv