Effects of Force in the Martian Plasma Environment With Solar Wind Dynamic Pressure Enhancement

Abstract

As a terrestrial planet, Mars possesses a series of spatial structures and atmospheric evolution processes which are similar to the ones on Earth. It is widely believed that studying the plasma environment and atmospheric erosion mechanisms of Mars has important meanings for understanding the climate change in Mars history, as well as the future evolution of Earth's atmosphere. Unlike Earth, Mars does not have a global magnetic field of internal origin, but possesses remnant crustal magnetic field located mostly in the southern hemisphere (Acuna

Martian Bow Shock Oscillations Driven by Solar Wind Variations: Simultaneous Observations From Tianwen‐1 and MAVEN

“…The exact value of the response time is unknown, but must be less than 1 min. It reveals the rapid response of the bow shock to the solar wind variation, which is consistent with the simulations (Ma et al., 2014; Song et al., 2023). For the second event, if we assume that the bow shock kept static before the IMF rotation and responded to the solar wind instantaneously, after removing the propagation time of the solar wind, the ∼1‐min time difference between IMF rotation and t 2 would be the time needed for the bow shock to move from bow shock location at t 1 to that at t 2 .…”

Effects of Solar Wind Density and Velocity Variations on the Martian Ionosphere and Plasma transport—A MHD Model Study

“…The source terms considered in the MHD equations include inelastic collisions (charge exchange, recombination and photoionization) and elastic collisions (ion-neutral and ion-ion collisions). A detailed description of the MHD model can be found in Song et al (2023) The simulation was performed under the Mars-centered Solar Orbital (MSO) coordinate system. The X-axis points from Mars toward the Sun, the Z-axis points toward the north pole of Mars and is normal to the Martian orbital plane, while the Y-axis completes the right-handed coordinate system.…”

“…In this study, a 3D multi‐fluid MHD model that has been used and validated in several previous studies (e.g., S. Li, Lu, Cao, Cui, et al., 2022; S. Li, Lu, Cao, Mazelle, et al., 2022; Song et al., 2023) is applied to simulate the interaction between solar wind and the Martian ionosphere/induced magnetosphere. Four major ion species in Martian ionosphere, that is, H + , $${\mathrm{O}}_{2}^{+}$$, O + , and $${\text{CO}}_{2}^{+}$$, are included in the model.…”

“…Solar wind dynamic pressure ( P dyn ), which consists of solar wind density n sw and velocity V sw , is one of the most important external drivers that controls the variation of Martian space environment (e.g., Edberg et al., 2009; Nagy et al., 2004). Previous studies have proved that an enhancement of the solar wind dynamic pressure can compress the plasma boundaries to lower altitudes, alter the global magnetic topology, and increase the magnitude of magnetic forces and ion escape rates (e.g., Chu et al., 2021; Dong et al., 2015; Duru et al., 2020; Garnier et al., 2017; Ma et al., 2014; Song et al., 2023; Weber et al., 2019; Xu et al., 2018). However, the relative influences of solar wind velocity and density variations on the Martian plasma environment have seldomly been discussed separately, and the differences between the impacts caused by the solar wind density and velocity variation on the Martian plasma environment still need to be studied systematically.…”

“…compress the plasma boundaries to lower altitudes, alter the global magnetic topology, and increase the magnitude of magnetic forces and ion escape rates (e.g., Chu et al, 2021;Dong et al, 2015;Duru et al, 2020;Garnier et al, 2017;Ma et al, 2014;Song et al, 2023;Weber et al, 2019;Xu et al, 2018). However, the relative influences of solar wind velocity and density variations on the Martian plasma environment have seldomly been discussed separately, and the differences between the impacts caused by the solar wind density and velocity variation on the Martian plasma environment still need to be studied systematically.…”