空间物理
We present evidence that the time delay between the multiple rings of elves is not caused by the ground reflection of the electromagnetic pulse produced by intracloud lightning. To investigate temporal differences of multi-elves, we…
The present investigation is directed at exploring southern polar ionospheric responses to intense space weather events and their correlations with plasma convection and auroral precipitation. The main phases of six geomagnetic storms…
The extremely weak gravity on small bodies makes landers prone to rebound and uncontrolled drift. To mitigate this, the Hayabusa2 mission employed a particle-filled flexible shell, but the coupled dynamics of shell deformation and internal…
Kelvin-Helmholtz (KH) vortices are widely observed in astrophysics and heliophysics, including at Jovian and terrestrial magnetopauses, the Martian sheath-ionosphere boundary, the heliopause, and within stellar accretion disks. These…
This study investigates the applicability of the semi-implicit particle-in-cell code FLEKS to heliospheric shock simulations. We examine one- and two-dimensional local planar shock simulations, initialized using MHD states with upstream…
Accurately observing the rarefied media of the upper atmosphere, exosphere, and planetary and solar system environments and beyond requires highly sensitive metrological techniques. We present the operating concept and architecture of an…
We present a novel nonlinear model for whistler-mode chorus amplification based on the free-electron laser (FEL) mechanism. First, we derive the nonlinear collective variable equations for the whistler-electron interaction. Consistent with…
While humans become more reliant on Earth's space environment, the potential for significant harm from severe space weather continues to grow. As structures from the sun reach Earth's magnetosphere and space environment, they deposit energy…
Interstellar neutral (ISN) atoms enable studies of the physical conditions in the local interstellar medium surrounding the heliosphere. ISN helium, which is the most abundant species at 1 au, is directly observed by space missions, such as…
Accurate space weather forecasting is crucial for protecting our increasingly digital infrastructure. Hybrid-Vlasov models, like Vlasiator, offer physical realism beyond that of current operational systems, but are too computationally…
Plasma waves in the magnetosphere scatter electrons, causing them to precipitate into Earth's atmosphere, imparting their temporal characteristics to diffuse auroras. In a case study of conjugate radar and satellite observations, we…
During the 23 April 2023 geospace storm, we observed chorus wave-driven, energetic particle precipitation on closed magnetic field lines in the dayside magnetosphere. Simultaneously and in the ionosphere's bottom-side, we observed…
Solar sail technology is ready to be deployed in a satellite mission carrying a science-grade magnetometer. In preparation for such a mission, it is essential to characterize the interactions between the sail and the ambient plasma that…
Magnetic reconnection is a fundamental and omnipresent energy conversion process in plasma physics. Novel observations of fields and particles from Parker Solar Probe (PSP) have shown the absence of reconnection in a large number of current…
Mars, lacking an intrinsic dynamo, is an ideal laboratory to comparatively study induced magnetospheres, which can be found in other terrestrial bodies as well as comets. Additionally, Mars is of particular interest to further exploration…
Over the last few decades, prediction models have become a fundamental tool in statistics, chemometrics, and related fields. However, to ensure that such models have high value, the inferences that they generate must be reliable. In this…
We present an automated approach for identifying magnetospheric regions using supervised machine learning techniques applied to Magnetospheric MultiScale mission data. Our method utilizes ion energy spectra, total magnetic field, total ion…
The origin, acceleration and anisotropy of suprathermal ions in the interplanetary medium during quiet periods have remained poorly understood issues in solar wind physics. To address these aspects, we derive the spectral indices for the…
We apply SHAP (SHapley Additive exPlanations) analysis using the TreeSHAP algorithm to a Random Forest model (RANDM) designed to predict thermospheric neutral density based on solar-terrestrial data. The analysis shows that RANDM identifies…
The Combined Release and Radiation Effects Satellite (CRRES) observed the response of the Van Allen radiation belts to peak solar activity within solar cycle 22. This study analyses relativistic and ultra-relativistic electron occurrence…