Electron dynamics plays a crucial role in the evolution of the Martian ionosphere. However, the adiabatic process, a classical mechanism for modulating electron energy and pitch-angle distributions, has not been reported in this environment. Utilizing data from the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft, we present evidence of a decrease in electron perpendicular energy predominantly driven by betatron cooling in the Martian ionosphere. The phenomenon was identified within closed magnetic field lines at the edge of the crustal magnetic fields, a region characterized by a convoluted magnetic field topology comprising both closed and open lines. The observed cooling of 10–150 eV electrons with a power-law distribution, enhancing the cigar distribution, was quantitatively reproduced by an adiabatic model. Our study may promote the understanding of electron dynamics in the Martian ionosphere.

Edge detection represents a critical task in potential field data interpretation and is extensively utilized for detecting faults, contacts, and other linear geological structures. However, conventional methods are constrained by several limitations, including inadequate balancing of signals with varying amplitude intensities, dispersed detection results, and insufficient suppression of spurious signals. To overcome these challenges, we propose an improved edge detection method, designated as the hyperbolic tangent (TANH) function with Gaussian envelope constraints on the total gradient modulus tilt angle (THASTG). The THASTG method is formally defined as a tilt angle approach based on the total gradient modulus, incorporating dual constraints through a Gaussian envelope and a TANH function. We initially conducted comparative analyses between the THASTG and established methods by using complex models simulating three distinct geological scenarios, thereby validating the feasibility of the methodology. Subsequent application to real gravity data from the South China Sea region demonstrated that compared with conventional techniques, THASTG yields enhanced structural detail, improved boundary resolution, and superior noise suppression. This method effectively suppresses noise interference and successfully avoids the introduction of spurious boundaries while maintaining consistency with previously documented major tectonic features. This study provides high-resolution structural constraints for the South China Sea region, delineates the offshore extension of the Red River Fault system, and accurately maps the continent–ocean boundary configuration. Our results demonstrate that the proposed methodology provides an effective tool for precise structural characterization and in-depth analysis of geodynamic evolution processes.

To understand energy transfer during sudden stratospheric warming (SSW) events in the middle atmosphere, the 2023 SSW is studied by using the analysis tools of the multiscale window transform (MWT) and MWT-based localized energetics analysis and theory of canonical transfer (MS-ECT). The energy transfer in the mesosphere is diagnosed and compared with that in the stratosphere. The energy fields are first reconstructed onto three scale windows: a large-scale window, an SSW-scale window, and a synoptic-scale window. Results showed that the work done by pressure (pressure flux) plays a critical role in coupling the mesosphere and stratosphere during SSW events. The cross-scale energy transfer (canonical transfer) of available potential energy is always directed from the large-scale to the SSW-scale window, indicating the central role of baroclinic instability in both the stratosphere and mesosphere. Comparative analysis with the 2012–2013 SSW event revealed the consistent presence of baroclinic instability across both events. However, the 2023 event exhibited significantly stronger energy transfer magnitudes in the mesosphere. These results highlight the consistent role of baroclinic instability and pressure flux in mediating cross-scale energy transfer during SSWs, providing a clearer understanding of stratosphere–mesosphere coupling.

As a planet lacking a global magnetic field, Mars interacts directly with the solar wind, forming an induced magnetosphere that mediates energy transfer and atmospheric ion loss. The topology of this interaction and the resulting atmospheric ion escape are strongly influenced by the orientation of the interplanetary magnetic field (IMF). In this study, we utilize a hybrid model to investigate how variations in the IMF orientation shape ion current systems and atmospheric ion escape rates of O⁺, O₂⁺, CO₂⁺. We first perform simulations with a constant |B_sw|, where varying the IMF cone angle results in different strengths of the convective electric field (E_sw = V_sw × B_sw). Our results suggest that the spatial morphology of ion plumes undergoes a substantial evolution, forming a distinct cross-flow plume as the IMF rotates from perpendicular to parallel. These ion plumes exhibit a mass-dependent deflection, where heavier CO₂⁺ travel farther with larger gyroradii than lighter O⁺, acting as an asymmetric obstacle in the –Y_MSE hemisphere (where MSE is the Mars solar electric coordinate frame). In turn, the solar wind proton current develops pronounced asymmetries under a parallel IMF, becoming largely diffused in the −Y_MSE hemisphere because of the interaction with the additional plume obstacles. Consequently, the ion escape rates exhibit a nonmonotonic dependence on the IMF orientation, peaking under a parallel  IMF as escape shifts from a tail- to plume-dominated flow with substantial upstream enhancement. To decouple the effects of IMF geometry from those of the convective electric field, we further conduct a comparative simulation with constant  B_y  (hence constant |E_sw|), where the cone angle is varied by changing the B_x component while allowing |B_sw| to vary. With increasing B_x toward a parallel orientation, the total field magnitude grows, causing the Alfvén Mach number (M_A) to decrease from super-Alfvénic to trans-Alfvénic and ultimately to sub-Alfvénic values. Within the range from perpendicular to a 30° cone angle, where the system remains in the super-Alfvénic regime, ion escape is largely insensitive to the growing B_x component. This finding indicates that the magnetic barrier maintains its shielding efficiency under the super-Alfvénic regime.