Radio Absorption in the Nightside Ionosphere of Mars During Solar Energetic Particle Events
Abstract Characterization, understanding, and prediction of the Martian radio environment are of increasing importance to the forthcoming human exploration of Mars. Here we investigate 3–5 MHz radio absorption in the nightside ionosphere of Mars caused by enhanced ionization at <100 km altitudes...
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| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2023-12-01
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| Series: | Space Weather |
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| Online Access: | https://doi.org/10.1029/2023SW003755 |
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| _version_ | 1841536411915780096 |
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| author | Y. Harada Y. Nakamura B. Sánchez‐Cano M. Lester N. Terada F. Leblanc |
| author_facet | Y. Harada Y. Nakamura B. Sánchez‐Cano M. Lester N. Terada F. Leblanc |
| author_sort | Y. Harada |
| collection | DOAJ |
| description | Abstract Characterization, understanding, and prediction of the Martian radio environment are of increasing importance to the forthcoming human exploration of Mars. Here we investigate 3–5 MHz radio absorption in the nightside ionosphere of Mars caused by enhanced ionization at <100 km altitudes during solar energetic particle (SEP) events. We conduct a quantitative analysis of radio absorption and SEP flux data that have been accumulated by two spacecraft currently orbiting Mars, thereby demonstrating that radio absorption is clearly correlated with SEP fluxes. A comparison of the observations with radio absorption properties predicted by a numerical model indicates that the relative temporal changes, radio frequency dependence, and SEP energy dependence of the observed radio absorption are in agreement with the model prediction. Meanwhile, the model systematically overestimates the radio absorption in the ionosphere by a factor of 3.7. We explore several sources of uncertainty, including the electron‐neutral collision frequency, absolute sensitivity of the SEP instrument, and limited transport of SEPs to the atmosphere, but the ultimate cause of the systematic discrepancy between the measured and modeled radio absorption is yet to be identified. Further efforts should be put into the development of a comprehensive and observationally validated model of radio absorption in the Martian ionosphere to assist the future crew and spacecraft activities on the surface of Mars. |
| format | Article |
| id | doaj-art-779870a02dc94065af0a831e4a7306e5 |
| institution | Kabale University |
| issn | 1542-7390 |
| language | English |
| publishDate | 2023-12-01 |
| publisher | Wiley |
| record_format | Article |
| series | Space Weather |
| spelling | doaj-art-779870a02dc94065af0a831e4a7306e52025-01-14T16:30:45ZengWileySpace Weather1542-73902023-12-012112n/an/a10.1029/2023SW003755Radio Absorption in the Nightside Ionosphere of Mars During Solar Energetic Particle EventsY. Harada0Y. Nakamura1B. Sánchez‐Cano2M. Lester3N. Terada4F. Leblanc5Department of Geophysics Graduate School of Science Kyoto University Kyoto JapanDepartment of Earth and Planetary Science Graduate School of Science University of Tokyo Tokyo JapanSchool of Physics and Astronomy University of Leicester Leicester UKSchool of Physics and Astronomy University of Leicester Leicester UKGraduate School of Science Tohoku University Sendai JapanLATMOS/CNRS Sorbonne Université UVSQ IPSL Paris FranceAbstract Characterization, understanding, and prediction of the Martian radio environment are of increasing importance to the forthcoming human exploration of Mars. Here we investigate 3–5 MHz radio absorption in the nightside ionosphere of Mars caused by enhanced ionization at <100 km altitudes during solar energetic particle (SEP) events. We conduct a quantitative analysis of radio absorption and SEP flux data that have been accumulated by two spacecraft currently orbiting Mars, thereby demonstrating that radio absorption is clearly correlated with SEP fluxes. A comparison of the observations with radio absorption properties predicted by a numerical model indicates that the relative temporal changes, radio frequency dependence, and SEP energy dependence of the observed radio absorption are in agreement with the model prediction. Meanwhile, the model systematically overestimates the radio absorption in the ionosphere by a factor of 3.7. We explore several sources of uncertainty, including the electron‐neutral collision frequency, absolute sensitivity of the SEP instrument, and limited transport of SEPs to the atmosphere, but the ultimate cause of the systematic discrepancy between the measured and modeled radio absorption is yet to be identified. Further efforts should be put into the development of a comprehensive and observationally validated model of radio absorption in the Martian ionosphere to assist the future crew and spacecraft activities on the surface of Mars.https://doi.org/10.1029/2023SW003755Marsradio absorptionsolar energetic particles |
| spellingShingle | Y. Harada Y. Nakamura B. Sánchez‐Cano M. Lester N. Terada F. Leblanc Radio Absorption in the Nightside Ionosphere of Mars During Solar Energetic Particle Events Space Weather Mars radio absorption solar energetic particles |
| title | Radio Absorption in the Nightside Ionosphere of Mars During Solar Energetic Particle Events |
| title_full | Radio Absorption in the Nightside Ionosphere of Mars During Solar Energetic Particle Events |
| title_fullStr | Radio Absorption in the Nightside Ionosphere of Mars During Solar Energetic Particle Events |
| title_full_unstemmed | Radio Absorption in the Nightside Ionosphere of Mars During Solar Energetic Particle Events |
| title_short | Radio Absorption in the Nightside Ionosphere of Mars During Solar Energetic Particle Events |
| title_sort | radio absorption in the nightside ionosphere of mars during solar energetic particle events |
| topic | Mars radio absorption solar energetic particles |
| url | https://doi.org/10.1029/2023SW003755 |
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