Japan Geoscience Union Meeting 2023

Presentation information

Print

[E] Oral

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

[P-PS05] Mars and martian moons

Tue. May 23, 2023 10:45 AM - 12:00 PM Exhibition Hall Special Setting (3) (Exhibition Hall 8, Makuhari Messe)

convener:Hideaki Miyamoto(University of Tokyo), Takeshi Imamura(Graduate School of Frontier Sciences, The University of Tokyo), Tomoki Nakamura(Department of Earth and Planetary Materials Sciences, Faculty of Science, Tohoku University), Hidenori Genda(Earth-Life Science Institute, Tokyo Institute of Technology), Chairperson:Takeshi Imamura(Graduate School of Frontier Sciences, The University of Tokyo), Tomohiro Usui(Japan Aerospace Exploration Agency), Hideaki Miyamoto(University of Tokyo)

11:30 AM - 11:45 AM

[PPS05-09] Formation altitudes of cloud trains associated with mountain lee waves in the northern hemisphere of Mars

★Invited Papers

*Kazunori Ogohara1, MAAYA RO1 (1.Faculty of Science)

Keywords:Mars atmosphere, water ice cloud, gravity wave

Mountain lee waves have often been observed on the eastern side of the Phlegra Montes as wave trains visualized by water ice clouds in the Martian atmosphere. The seasonality and formation condition of these lee waves and associated cloud trains have not yet been investigated, whereas those of Martian dust storms have been studied observationally and numerically. We extract the cloud trains in this region from images observed by the Mars Orbiter Camera onboard the Mars Global Surveyor and measure the wavelengths of the lee waves. It is revealed that, on the eastern side of the Phlegra Montes, cloud trains tend to form in the northern winter season, except during the 2001 global dust storm. The results suggest that stationary mountain waves are excited in the thermally stable atmosphere, but are trapped below an altitude of approximately 10 km due to the zonal wind structure that increases rapidly with altitude. This is consistent with the previous studies on gravity waves in the Martian atmosphere and is the first study to constrain the typical altitude of the cloud trains from imager observations.