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Kumar A, England SL, Liu G, Jain S, Schneider NM. Observations of Atmospheric Tides in the Middle and Upper Atmosphere of Mars From MAVEN and MRO. JOURNAL OF GEOPHYSICAL RESEARCH. PLANETS 2022; 127:e2022JE007290. [PMID: 36249322 PMCID: PMC9542092 DOI: 10.1029/2022je007290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 06/23/2022] [Accepted: 07/01/2022] [Indexed: 06/16/2023]
Abstract
Variability in the Martian upper atmosphere is strongly linked to the lower atmosphere and much of it can be attributed to vertical wave propagation. Atmospheric tides in particular are a well-known phenomenon in the Martian atmosphere that play a key role in the transport of energy as they propagate to higher altitudes. Previous theoretical predictions and observations suggest that tides producing wavenumber-2 and wavenumber-3 patterns are strongest in a fixed local time at high altitudes, however, the energy they carry and the region of deposition are not well characterized. Given the availability of atmospheric observations from several spacecraft at the same time, in this paper, the nature and behavior of tides are studied concurrently at several altitudes. Here, six intervals are identified focused at fixed low latitudes utilizing simultaneous observations of the middle and upper atmosphere from in situ and remote sensing instruments on different spacecraft. In the middle atmosphere, strong wavenumber-2 signatures are identified in the intervals north of the equator whereas, in the south, wavenumber-3 signatures are strongest. Wave signatures observed in the upper atmosphere seem to be dominated by a mix of wavenumbers-2 and -3. Seasonal variation is observed in the northern intervals, with very little interannual variability in all intervals considered. Estimates of energy based on dominant wavenumber amplitude suggest that most of the energy dissipates below ∼90 km. Furthermore, model sampled output captures the dominant wavenumbers observed in the middle atmosphere as well as the energy dissipation characteristics.
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Affiliation(s)
- Aishwarya Kumar
- Aerospace and Ocean EngineeringVirginia Polytechnic Institute and State UniversityBlacksburgVAUSA
| | - Scott L. England
- Aerospace and Ocean EngineeringVirginia Polytechnic Institute and State UniversityBlacksburgVAUSA
| | - Guiping Liu
- Space Sciences LaboratoryUniversity of California BerkeleyBerkeleyCAUSA
| | - Sonal Jain
- Laboratory for Atmospheric and Space PhysicsUniversity of Colorado BoulderBoulderCOUSA
| | - Nicholas M. Schneider
- Laboratory for Atmospheric and Space PhysicsUniversity of Colorado BoulderBoulderCOUSA
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Fang X, Forbes JM, Gan Q, Liu G, Thaller S, Bougher S, Andersson L, Benna M, Eparvier F, Ma Y, Pawlowski D, England S, Jakosky B. Tidal Effects on the Longitudinal Structures of the Martian Thermosphere and Topside Ionosphere Observed by MAVEN. JOURNAL OF GEOPHYSICAL RESEARCH. SPACE PHYSICS 2020; 126:e2020JA028562. [PMID: 33796432 PMCID: PMC8011558 DOI: 10.1029/2020ja028562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 12/18/2020] [Indexed: 06/12/2023]
Abstract
Longitudinal structures in the Martian thermosphere and topside ionosphere between 150 and 200 km altitudes are studied using in situ electron and neutral measurements from the NASA Mars Atmosphere and Volatile EvolutioN (MAVEN) mission. Four time intervals are selected for comparison, during which MAVEN sampled similar local time (9.3-10.3 h) and latitude (near 20°S) regions but at different solar longitude positions (two near northern summer solstice, one each at northern vernal and autumnal equinoxes). Persistent and pronounced tidal oscillations characterize the ionosphere and thermosphere, whose longitudinal variations in density are generally in-phase with each other. Our analysis of simultaneous and collocated neutral and electron data provides direct observational evidence for thermosphere-ionosphere coupling through atmospheric tides. We conclude that the ionosphere is subject to modulation by upward-propagating thermal tides, via both tide-induced vertical displacement and photochemical reactions. Atmospheric tides constitute a ubiquitous and significant perturbation source to the ionospheric electron density, up to ~15% near 200 km.
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Affiliation(s)
- Xiaohua Fang
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO, USA
| | - Jeffrey M Forbes
- Ann and H.J. Smead Department of Aerospace Engineering Sciences, University of Colorado, Boulder, CO, USA
| | - Quan Gan
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO, USA
| | - Guiping Liu
- Space Sciences Laboratory, University of California, Berkeley, CA, USA
| | - Scott Thaller
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO, USA
| | - Stephen Bougher
- Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Laila Andersson
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO, USA
| | - Mehdi Benna
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - Francis Eparvier
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO, USA
| | - Yingjuan Ma
- Department of Earth, Planetary and Space Sciences, University of California, Los Angeles, CA, USA
| | - David Pawlowski
- Physics and Astronomy Department, Eastern Michigan University, Ypsilanti, MI, USA
| | - Scott England
- Department of Aerospace and Ocean Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Bruce Jakosky
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO, USA
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