MESSENGER Observations of Mercury's Planetary Ion Escape Rates and Their Dependence on True Anomaly Angle
| Title: | MESSENGER Observations of Mercury's Planetary Ion Escape Rates and Their Dependence on True Anomaly Angle |
|---|---|
| Authors: | Weijie Sun, Ryan M. Dewey, Xianzhe Jia, Jim M. Raines, James A. Slavin, Yuxi Chen, Tai Phan, Gangkai Poh, Shaosui Xu, Anna Milillo, Robert Lillis, Yoshifumi Saito, Stefano Livi, Stefano Orsini |
| Source: | Geophysical Research Letters, Vol 51, Iss 13, Pp n/a-n/a (2024) |
| Publisher Information: | Wiley, 2024. |
| Publication Year: | 2024 |
| Collection: | LCC:Geophysics. Cosmic physics |
| Subject Terms: | planetary ions escape, ion plumes, Mercury's exosphere, Geophysics. Cosmic physics, QC801-809 |
| More Details: | Abstract 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), that is, 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 × 1025 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. |
| Document Type: | article |
| File Description: | electronic resource |
| Language: | English |
| ISSN: | 1944-8007 0094-8276 |
| Relation: | https://doaj.org/toc/0094-8276; https://doaj.org/toc/1944-8007 |
| DOI: | 10.1029/2023GL107689 |
| Access URL: | https://doaj.org/article/4f275d61617241f8b1fc6b49c6201356 |
| Accession Number: | edsdoj.4f275d61617241f8b1fc6b49c6201356 |
| Database: | Directory of Open Access Journals |
| ISSN: | 19448007 00948276 |
|---|---|
| DOI: | 10.1029/2023GL107689 |
| Published in: | Geophysical Research Letters |
| Language: | English |