Science Seminars

Martian Dust Storm Disturbance to the Near-Planet Space Environment and Implications for Atmospheric Loss

Speaker: Xiaohua Fang (LASP)
Date: Thursday, Jan 24, 2019
Time: 4:00 PM
Location: SPSC W120

Seminar Abstract:

Mars experiences regional and planet-encircling dust storms episodically, during which dust particles are lifted to significantly high altitudes over a broad area of the surface. These dust events intensify atmospheric heating through the absorption of solar radiation, followed by significant alteration of the atmospheric thermal structure and circulation regionally and even globally. While the dust impact on the atmosphere has been paid attention to, little is known about whether and how this type of events may extend its effectiveness to the surrounding plasma environment (including the ionosphere and induced magnetosphere). In this study, we apply a Mars multifluid magnetohydrodynamic (MHD) model to quantify the ionospheric and magnetospheric effects of a 2017 regional dust storm and one of the greatest global dust storm in 1971. Our results show that ionospheric densities can be significantly disturbed during dust storms. The net effect of dust storms on the ionosphere is basically an upwelling of the main ionospheric body. The ionospheric peak density is barely affected. The altitude shift of the ionospheric peak is in accordance with the expansion of the upper atmosphere during dust storms. It is found that a strong global dust storm is able to dramatically enhance total carbon loss in the form of CO2+ through MHD processes, with a factor of more than 2.