A warm layer in the nightside mesosphere of Mars

Hiromu Nakagawa (1) , Sonal K. Jain (2) , Nicholas M. Schneider (2) , Franck Montmessin (3) , Roger V. Yelle (4) , F. Jiang (4) , Loïc Verdier (5) , Takeshi Kuroda (1) , Nao Yoshida (1) , Hitoshi Fujiwara (6) , Takeshi Imamura (7) , Naoki Terada (1) , Kaori Terada (1) , Kanako Seki (8) , Hannes Gröller (4) , Justin I. Deighan (2)

1 Graduate School of Information Sciences [Sendai]
2 LASP - Laboratory for Atmospheric and Space Physics [Boulder]
3 PLANETO - LATMOS
4 LPL - Lunar and Planetary Laboratory [Tucson]
5 LATMOS - Laboratoire Atmosphères, Milieux, Observations Spatiales
6 Faculty of Science and Technology [Tokyo]
7 Graduate School of Frontier Sciences [Kashiwa]
8 Graduate School of Science [Tokyo]

We report a new set of stellar occultation measurements for nightside temperature profiles made by the MAVEN/IUVS that provide evidence for a recurring layer of warm air between 70‐90 km altitudes in the nightside mesosphere of Mars during Ls = 0° ‐ 180° in Martian Year 33‐34. The nightside profiles reveal a recurring peak of atmospheric temperature around 80 km over the equator to the middle latitudes in the northern hemisphere. The predictions of the Mars Climate Database have a warm layer with much smaller amplitudes. The observed peak amplitudes are larger than those predicted by the model by up to 90 K. Wavenumber‐3 structures are seen in the warm layer that are potentially signatures of thermal tides or stationary planetary waves, with amplitudes two‐times larger than predicted.

Domaines: Planète et Univers [physics]

Hiromu Nakagawa, Sonal K. Jain, Nicholas M. Schneider, Franck Montmessin, Roger V. Yelle, et al.. A warm layer in the nightside mesosphere of Mars. Geophysical Research Letters, 2020, 47 (4), pp.e2019GL085646. ⟨10.1029/2019GL085646⟩. ⟨insu-02476853⟩