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

Abstract

Global or planet encircling dust storms, a prominent phenomenon on Mars, are known to cause dynamic changes in atmospheric parameters such as neutral densities, temperature and pressure around most of the planet (Smith et al., 2002). During the storm event, the dust particles are elevated to greater heights and can remain at these altitudes for several months (Clancy et al., 2010). 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 (

The Origins of Long‐Term Variability in Martian Upper Atmospheric Densities

“…Dust activity is another non‐negligible contributor to atmospheric disturbances at Mars. The dust storm effects on the atmospheric thermal structure and the distributions of neutral winds and densities are well recognized in the lower and middle atmospheres, and the impact is also noticed to be extended into high altitudes in the neutral regime (thermosphere and exosphere) and in the plasma regime (ionosphere and magnetosphere) (e.g., Keating et al., 1998; Withers & Pratt, 2013; Fang et al., 2020; Elrod et al., 2020; Lee et al., 2020; Mukundan et al., 2021). As dust particles are mostly confined below ∼80 km altitude (Clancy et al., 2010), the dust‐induced effects in the upper atmosphere act essentially indirectly through the upward coupling from the middle atmosphere (Bougher et al., 1997).…”

Atypically Intense and Delayed Response of the Martian Ionosphere to the Regional Dust Storm of 2016: A Study Using MAVEN Observations and Models

“…(2020) and Mukundan et al. (2021), for extending the neutral densities to lower heights. The method fits the NGIMS‐measured neutral profiles and extrapolate it to lower heights using the following equation: $$$\mathrm{n}(\mathrm{Z})=\sum\limits _{i=1}^{m}{n}_{0i}\ \mathrm{exp}\frac{-(Z-100)}{{H}_{i}}$$$ where n ( Z ) is the number density of an atmospheric species at altitude Z .…”

“…At any given altitude, density is dominated by one component as the scale heights associated with each component are largely different. For a detailed description of the multicomponent fit approximation, the reader is referred to Mukundan et al (2021).…”

“…To isolate the effect of SZA variability on the changes in the ionospheric peak altitude, we calculated the subsolar peak altitude of the ROSE profiles using Chapman theory as follows: $$${Z}_{0}={Z}_{m}-H\ \mathrm{ln}[Ch(x,\chi )]$$$ where Z m is the peak altitude at SZA χ , Z 0 is the subsolar peak altitude, and Ch( x , χ ) is the Chapman grazing function. The parameter x is defined as x = [( R M + Z m )/ H ] where R M is the Martian radius which is ∼3,390 km and H is the neutral height and is assumed to be 10 km (Mukundan et al., 2021; Vogt et al., 2017; Withers, 2006) in the calculations. The corresponding subsolar peak density is calculated as follows: $$${N}_{o}={N}_{m}{[Ch(x,\chi )]}^{0.5}$$$ where N m is the peak density at SZA χ .…”

“…There have been many studies on the Martian ionospheric response to dust storms. Starting from the global dust storm event of 1971, many of these studies concentrated on the thermospheric and ionospheric responses to global dust storm events (Elrod et al., 2020; Kliore et al., 1972; Mukundan et al., 2021; Smith et al., 2002; Wang & Nielsen, 2003) as global storms cause more pronounced changes. The effects of local and regional storms have also been investigated.…”