Japan Geoscience Union Meeting 2016

Presentation information

International Session (Oral)

Symbol P (Space and Planetary Sciences) » P-PS Planetary Sciences

[P-PS02] Mars

Mon. May 23, 2016 1:45 PM - 3:15 PM 104 (1F)

Convener:*Takehiko Satoh(Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency), Masaki Ishiwatari(Department of Cosmosciences, Graduate school of Science, Hokkaido University), Sho Sasaki(Department of Earth and Space Sciences, School of Science, Osaka University), Yoshiyuki O. Takahashi(Graduate School of Science, Kobe University), Ayako Matsuoka(Research Division for Space Plasma, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency), Hideaki Miyamoto(The University Museum, The University of Tokyo), Sushil Atreya(University of Michigan Ann Arbor), Chair:Yoshiyuki O. Takahashi(Graduate School of Science, Kobe University)

1:45 PM - 2:10 PM

[PPS02-01] Comparison of the Martian thermospheric density and temperature from IUVS/MAVEN data and general circulation modeling

★Invited papers

*Hiromu Nakagawa1, Alexander S Medvedev3, Chris Mockel3, Erdal Yigit3, Takeshi Kuroda1, Paul Hartogh3, Kaori Terada1, Naoki Terada1, Kanako Seki2, Nichlas M Schneider4, Sonal Jain4, Scott Evans5, Justin I Deighan4, William McClintock4, Daniel Lo6 (1.Planetary Atmosphere Physics Laboratory, Department of Geophysics, Graduate School of Science, Tohoku University, 2.Graduate School of Science, University of Tokyo, 3.Max Plank Institute for Solar System Reserach, Gottingen, Germany, 4.Laboratory for Atmospheric and Space Physics, University of Colorado Boulder, 5.Computational Physics, Inc., 6.Lunar and Planetary Laboratory, University of Arizona)

Keywords:Gravity waves, Tides, MAVEN

The Mars Atmosphere and Volatile Evolution (MAVEN) Mission, which operates for slightly over one year to date, has been specifically designed for investigating the upper atmosphere. The Imaging Ultraviolet Spectrograph (IUVS) onboard MAVEN measures spectra of mid- and far UV atmospheric emission, which are used for retrieving vertical density profiles of CO2 and other species.
Newly released IUVS/MAVEN measurements of CO2 density in the Martian thermosphere have been used for comparison with the predictions of the Max Planck Institute Martian General Circulation Model (MPI-MGCM). In this study, we focus on the October 2014 campaign in which a total of 122 density profiles were obtained for the period between 18 and 22 October (Ls=216.68-218.94). IUVS nicely covers the thermosphere in the altitude range of 130-220 km. The MGCM demonstrated the sensitivity of simulated density and temperature profiles on (i) solar flux, (ii) atomic oxygen, and (iii) small-scale gravity waves (GWs). It is the only MGCM to date that includes a parameterization of effects of subgrid-scale GWs with broad spectra.
The simulations reproduced (within one standard deviation) the available zonal mean density and derived temperature above 130 km. The comparison shows a great role of gravity waves in the thermosphere, and in bringing the simulated density and temperature closer to observations.
The MGCM replicated the observed dominant zonal wavenumber-3 non-migrating tide, which was already reported by MAVEN measurements (Lo et al., 2015). The simulations also demonstrated that it represents a non-moving imprint of the topography in the thermosphere.
This comparison confirms that, with the current state of knowledge of the Martian thermospheric physics, MGCM can reproduce its state and variability. Further observations will help to constrain physical parameterizations and improve modeling capabilities.