空间物理
The weakly ionized plasma in the Earth's ionosphere is controlled by a complex interplay between solar and magnetospheric inputs from above, atmospheric processes from below, and plasma electrodynamics from within. This interaction results…
Using particle data from the ELFIN satellites, we present a statistical study of 284 proton isotropy boundary events on the nightside magnetosphere, characterizing their occurrence and distribution in local time, latitude (L-shell), energy,…
Utilizing observations from the ELFIN satellites, we present a statistical study of $\sim$2000 events in 2019-2020 characterizing the occurrence in magnetic local time (MLT) and latitude of $\geq$50 keV electron isotropy boundaries (IBs) at…
Shock drift acceleration plays an important role in generating high-energy electrons at quasi-perpendicular shocks, but its efficiency in low beta plasmas is questionable. In this article, we perform a two-dimensional particle-in-cell…
Exposure to cosmic radiation is a major concern in space exploration. On the Martian surface, a complex radiation field is present, formed by a constant influx of galactic cosmic radiation and the secondary particles produced by their…
Kinetic scale dynamics in weakly-collisional space plasmas usually exhibits a self-similar statistics of magnetic field fluctuations which implies the existence of an invariant probability density function (master curve). We provide an…
Updated summaries of the August 1972 and March 1989 space weather events have been constructed. The features of these two events are compared to the Carrington 1859 event and a few other major space weather events. It is concluded that…
Conjunction analysis (CA) for resident space objects (RSOs) is essential for preventing collisions in an increasingly crowded orbital environment and preserving the operational integrity of satellites. A first and fundamental step in the CA…
The Colaba, India ~-1600 nT magnetic spike caused by an interplanetary sheath magnetic field inducing a "dayside R1-field aligned current wedge" during the Carrington magnetic storm proposed by Ohtani (2022,…
Owing to the ever-present solar wind, our vast solar system is full of plasmas. The turbulent solar wind, together with sporadic solar eruptions, introduces various space plasma processes and phenomena in the solar atmosphere all the way to…
Earth's magnetotail, a night-side region characterized by stretched magnetic field lines and strong plasma currents, is the primary site for the release of magnetic field energy and its transformation into plasma heating and kinetic energy…
The recent superstorm of 2024 May 10-11 is the second largest geomagnetic storm in the space age and the only one that has simultaneous interplanetary data (there were no interplanetary data for the 1989 March storm). The May superstorm was…
Space debris has become a critical issue, with debris in orbit surpassing active satellites, posing significant risks to space sustainability. Payloads or rocket bodies discarded post-mission in LEO without orbital control are major…
Chorus is one of the strongest electromagnetic emissions naturally occurring in space, and can cause hazardous radiations to humans and satellites1-3. Although chorus has attracted extreme interest and been intensively studied for…
The paper presents a novel concept of a 3D structural metasurface with mechanically morphing capability that can be used as a transmit- or reflect-array to manipulate electromagnetic beams for applications in RF sensing and communications…
It is shown, using results of fully kinetic 3D numerical simulations and observations in solar wind and Earth's magnetosphere that the transition from deterministic chaos to turbulence at kinetic (sub-ion) scales in space plasmas is…
Super-Alfv\'enic jets, with kinetic energy densities significantly exceeding that of the solar wind, are commonly generated downstream of Earth's bow shock under both high and low beta plasma conditions. In this study, we present…
Coronal mass ejections (CMEs) are magnetized plasma systems with highly complex magnetic topology and evolution. Methods developed to assess their magnetic configuration have primarily focused on reconstructing three-dimensional…
Collisionless low Mach number shocks are abundant in astrophysical and space plasma environments, exhibiting complex wave activity and wave-particle interactions. In this paper, we present 2D Particle-in-Cell (PIC) simulations of…
We report, for the first time, the impact of an interplanetary coronal mass ejection (ICME) on the recently discovered O($^1$S) 557.7 nm dayglow emission in the Martian atmosphere. Although there are only a few studies on the seasonal…