The induced magnetosphere of Mars is highly dynamic, driven by both the upstream solar wind and the planet’s crustal magnetic fields. This variability can occur on timescales much shorter than a single spacecraft orbit, making it difficult to distinguish between spatial and temporal variations in the induced magnetosphere. In this study, we utilize simultaneous multipoint observations from the Mars Atmosphere and Volatile EvolutioN (MAVEN) and Tianwen-1 missions to investigate how the induced magnetosphere responds to dynamic changes in the solar wind. We report a magnetic reconnection event observed by MAVEN in the Martian magnetotail, occurring a few minutes after an interplanetary magnetic field (IMF) rotation observed by Tianwen-1 in the upstream solar wind. This reconnection event is characterized by clear Hall magnetic field signatures and high-speed ion jets, indicating the presence of a diffusion region. Our analysis of the change in the magnetic field morphology suggests that this reconnection was likely triggered by this IMF rotation, occurring during the resulting reconfiguration of the induced magnetosphere. This multipoint study demonstrates the important role of dynamic upstream solar wind conditions, particularly IMF rotations, in driving the plasma processes in the Martian magnetotail, contributing to our understanding of solar wind energy and momentum transfer and their roles in ion escape in Mars’s hybrid magnetosphere.

This study presents signatures of seismo-ionospheric perturbations possibly related to the 14 July 2019 $ {M}_{w} $7.2 Laiwui earthquake, detected by a cross-validation analysis of total electron content (TEC) data of the global ionospheric map (GIM) from GPS and plasma parameter data recorded by the China Seismo-Electromagnetic Satellite (CSES). After separating pre-seismic ionospheric phenomena from the ionospheric disturbances due to the magnetospheric and solar activities, we have identified three positive temporal anomalies, around the epicenter, at 1 day, 3 days and 8 days before the earthquake (14 July 2019), along with a negative anomaly 6 days after the earthquake. These results agree well with the TEC spatial variations in latitude–longitude–time (LLT) maps. To confirm these anomalies further, we employed the moving mean method (MMM) to analyze ionospheric plasma parameters (electron, $ {\mathrm{O}}^{+} $and $ {\mathrm{H}\mathrm{e}}^{+} $densities) recorded by the Langmuir probe (LAP) and Plasma Analyzer Package (PAP) onboard the CSES. The analysis detected on, on Day Two, Day Four, and Day Seven before the earthquake, remarkable enhancements along the orbits around when in proximity to the epicenter. To make the investigations still more convincing, we compared the orbits on which anomalous readings were recorded to their corresponding four nearest revisiting orbits; the comparison did indeed indicate the existence of plasma parameter anomalies that appear to be associated with the Laiwui earthquake. All these results illustrate that the unusual ionospheric perturbations detected through GPS and CSES data are possibly associated with the $ {M}_{w}7.2 $ Laiwui earthquake, which suggests that at least some earthquakes may be predicted by alertness to pre-seismic ionospheric anomalies over regions known to be at seismic risk. This case study also contributes additional information of value to our understanding of lithosphere–atmosphere–ionosphere coupling.

This work is an attempt to critically analyze the correlation between great deep-focus undersea earthquake and possible ionospheric anomalies. The significant TEC (total electron content) temporal and spatial anomalies were detected over the epicenter of 2007 M_w7.5 Jakarta–Java earthquake, and they coincide well with the striking plasma anomalies in the ionosphere in situ observed by the LEO (low Earth orbit) satellite. The localization and synchronization of the disturbances during the earthquake suggest that these ionospheric anomalies are highly related to this large undersea earthquake. In order to identify this correlation, we made efforts to distinguish seismo-associated signals from large electromagnetic noise due to solar and geomagnetic activities, natural non-seismic sources and known artificial signals. Nevertheless, the difficulties of this work should be recognized and approached with caution. This special (deep-focus and undersea) case study here provides us with valuable information on the study of lithosphere–atmosphere–ionosphere (LAI) coupling process and reminds us that deep-focus undersea seismic events need to be treated more carefully and discreetly in the future.

Magnetotail current sheet (CS) flapping is a universal plasma phenomenon observed at multiple planets, yet its triggering mechanisms remain poorly understood outside of Earth. At Mars, single‐spacecraft observations have also reported tail flapping, but the processes responsible for its onset have never been identified. In this study, we investigate the potential correlation between magnetic reconnection and magnetotail flapping using multipoint measurements from Mars Atmosphere and Volatile EvolutioN (MAVEN) and Tianwen‐1 (TW‐1) missions. We analyze an example event in which MAVEN observed a reconnection‐associated CS crossing in the near tail while TW‐1 simultaneously detected CS flapping further downtail. A statistical survey of joint observations from November 2021 to February 2024 identifies that about two‐thirds of TW‐1 flapping events coincide with reconnection signatures observed by MAVEN. Multiple magnetic flux ropes were also detected before or during flapping intervals, similar to previous observations at Earth, suggesting that reconnection‐generated magnetic flux ropes may propagate tailward and drive plasma instabilities that trigger the tail flapping at Mars. These results provide the first multipoint evidence of a potential statistical correlation between magnetic reconnection and magnetotail flapping at Mars, enabling us to explore the potential triggering mechanism of magnetotail flapping. Our findings also offer new insights into Martian magnetotail dynamics and broaden the comparative understanding of this fundamental plasma process across planetary environments.

In this study, we investigated the role of interplanetary magnetic field (IMF) orientation in controlling the location and structure of the current sheet (CS) in the Martian magnetotail. Based on carefully selected cases as well as statistical studies using the magnetic field and plasma data of Mars Atmosphere and Volatile EvolutioN from 2014 October to 2020 February, our work shows that the IMF orientation can systematically influence the magnetotail CS structure of Mars. Our results reveal a systematic dawn–dusk ( Y -axis) asymmetry in CS positioning under different IMF orientations. Specifically, a sunward-directed IMF (cone angle < 60°) shifts the CS toward the dusk (+ Y ) hemisphere, while a tailward-directed IMF (cone angle > 120°) shifts it toward the dawn (− Y ) hemisphere. Under cross-flow IMF conditions (70° < cone angle < 110°), no significant CS displacement is observed. This pattern persists even after accounting for possible confounding influences such as Martian crustal magnetic fields and solar EUV intensity. Our findings suggest that the cone angle of the IMF can systematically control the CS structure and magnetic lobes in the magnetotail of Mars. This IMF-controlled CS asymmetry has implications for understanding planetary ion escape and magnetotail dynamics at unmagnetized bodies.

This study statistically compares ion properties between the thermal core and total ion populations in the Martian magnetosheath, based on observations collected by the Mars Atmosphere and Volatile EvolutioN (or MAVEN) spacecraft from 2015 to 2023. Ion moments for the core population are derived by fitting measured three-dimensional ion velocity distributions with bi-Maxwellian functions, whereas those for the total population are obtained by directly computing weighted sums over the distributions. The core population accounts for a median of approximately 80% of the total number density and dominates the bulk flow of the total population. In contrast, the total population exhibits significantly higher temperature, thermal pressure, and plasma beta, primarily due to the presence of suprathermal ions. Both populations exhibit greater temperature anisotropies downstream of quasi-perpendicular shocks compared to quasi-parallel shocks, consistent with stronger shock compression and a greater contribution from gyrating reflected ions under quasi-perpendicular conditions. Notably, the core population consistently exhibits significantly higher temperature anisotropy than the total population under both shock geometries, suggesting the presence of additional perpendicular heating mechanisms acting on the core population beyond shock compression. One plausible mechanism is stochastic energization by kinetic Alfvén waves. Overall, this systematic comparison of ion parameters between the core and total populations provides new insights into the thermodynamic structure and governing processes of the Martian magnetosheath.