A Technique for Retrieving the Exospheric Number Density Distribution from Pickup Ion Ring Distributions
Abstract Ion pickup by the solar wind is ubiquitous in space plasma. Because pickup ions are originally produced by ionization of an exospheric neutral atmosphere, their measurements contain information on the exospheric neutral abundance. Here we established a method to retrieve exospheric number densities, by analyzing the ion velocity distribution functions of pickup ions measured by the Mars Atmosphere and Volatile EvolutioN spacecraft. We successfully retrieved exospheric oxygen density distributions at altitudes ranging from 1000 to 10,000 km around Mars except for the vicinity of the bow shock. This method can be applied to other space missions to study the upper atmosphere of planets, moons, and other small bodies in our solar system, where pickup ions exist.
Authors
- Naoki Terada (ORCID: https://orcid.org/0000-0001-5685-9736)
- K. Seki (ORCID: https://orcid.org/0000-0001-5557-9062)
- Shoichiro Yokota (ORCID: https://orcid.org/0000-0001-8851-9146)
- Yuki Harada (ORCID: https://orcid.org/0000-0002-4001-6352)
- Tomohiro Usui (ORCID: https://orcid.org/0000-0002-4653-293X)
- Shotaro Sakai (ORCID: https://orcid.org/0000-0001-9135-2076)
- Kei Masunaga (ORCID: https://orcid.org/0000-0001-9704-6993)
- Atsushi Yamazaki (ORCID: https://orcid.org/0000-0001-6468-6812)
- François Leblanc (ORCID: https://orcid.org/0000-0002-5548-3519)
- Takuya Hara (ORCID: https://orcid.org/0000-0003-4605-8454)
- J. P. McFadden
Publication Details
- Journal
- The Planetary Science Journal
- Published
- 2024-08-01
- DOI
- https://doi.org/10.3847/psj/ad65d4
- Citations
- 1
- Primary Topic
- Astro and Planetary Science
- Type
- article
- Field-Weighted Citation Impact
- 0.33
Funders
- National Aeronautics and Space Administration
- Japan Society for the Promotion of Science London
- Japan Society for the Promotion of Science