Species‐dependent Response of the Martian Ionosphere to the 2018 Global Dust Event

Abstract

Dust storms are an outstanding phenomenon of the Martian climate, especially during spring and summer over the southern hemisphere (e.g., Zurek, 1982). When a dust storm occurs, a significant amount of dust particles are lifted upward into the atmosphere by wind-related processes. Given that dust is the major absorber of solar radiation in the atmosphere, the lifted dust particles can cause the lower atmosphere to expand and modify the global circulation patterns (e.g., Bougher et al., 1997; Heavens et al., 2011). Changes

Seasonal and Dust‐Related Variations in the Dayside Thermospheric and Ionospheric Compositions of Mars Observed by MAVEN/NGIMS

“…Unexpected decreases in O during a global dust storm event were found in observations of the thermosphere (Elrod et al., 2019). The ionospheric compositions were also modified according to the atmospheric composition in the neutral atmosphere (Niu et al., 2021), which might support the idea that the escape of major ions would be modified by a global dust event. However, it is not clear how the composition in the upper atmosphere changes during a regional dust event.…”

“…A regional dust event was observed during this period (Montabone et al, 2015(Montabone et al, , 2020. A decrease in O density in the thermosphere during the planet-encircling dust event in 2018 was observed by Elrod et al (2019) and Niu et al (2021). We focus on the atmospheric composition during the regional dust event in Section 4.2.…”

Empirical Models of Ion Density Distribution in the Dayside Martian Ionosphere

“…These species demonstrate clear signatures of dawn-dusk asymmetry which cannot be captured by the proposed empirical models (see below). In addition, the H 2 O + distribution in the Martian ionosphere is substantially modulated by the thermospheric H 2 O variability, especially during global dust storms (Niu et al, 2021;Stone et al, 2020;Vandaele et al, 2019), implying the impact of an extra source of variability beyond the scope of this study.…”

Impact of the 2018 Mars Global Dust Storm on the Ionospheric Peak: A Study Using a Photochemical Model

“…These particles absorb solar radiation, warm the lower atmosphere and lead to the inflation of the atmosphere. Due to the coupling between the lower and upper atmospheric regions, the impact of storm events is seen even in the upper atmospheric regions including the thermosphere, ionosphere, exosphere, and magnetosphere where dust particles do not physically reach (S. W. Bougher et al., 1997; S. Bougher et al., 1999; Fang et al., 2020; Keating et al., 1998; Lee et al., 2020; Liu et al., 2018; Niu et al., 2021; Withers & Pratt, 2013). Due to thermospheric expansion, the ionospheric peak is seen to occur at significantly higher altitudes during storm events (Kliore, 1992; Withers et al., 2015).…”