Ion acceleration and corresponding bounce echoes were observed by MMS in the dayside outer magnetosphere

Observations and simulations suggest these echoes are driven by the accompanied electric field impulses

Impulse-induced ion radial transport with positive phase space density radial gradient leads to the observed pattern

Thermospheric wind measurements above 200 km show a prominent migrating wave associated with the evening solar terminator

The first observations of solar terminator wave altitude profiles reveal >200 km vertical wavelengths above 200 km

Comparison with numerical models suggests a lower atmospheric origin and the potentially significant role of gravity waves

This work compares the performance of long-term radiation belt simulations using various inputs and boundary conditions

Using GOES outer boundary condition, the benchmark simulations reproduce the radiation belt dynamics inside L* = 6 observed by Van Allen Probes

The data-driven OB condition is critical to the model performance, and stronger loss inside the plasmasphere could improve the performance

We report night-side relativistic electron precipitation associated with whistler-mode waves

Wave ducting is one possible explanation of the observed precipitating electron spectra

We examine the role of plasma injections and foreshock transients in relativistic electron losses

Four-spacecraft observations are used to estimate the normal and propagation velocity for more than 1,800 current sheets at 1 AU

MVA is highly inaccurate in estimating the current sheet normal, while the cross-product method delivers accurate estimates

Single-spacecraft methodology based on the cross-product normal and frozen-in assumption is accurate in estimating current sheet properties

Medium Energy Electron Telescope is a solid-state particle telescope designed to measure 30–800 keV electrons with fine energy resolution, and 1.1–>60 MeV protons

Geant4-guided instrument design includes consideration for collimator geometry, material, teeth, and the expected flux environment

Count rates are quantified for proving viability of science measurements, including proton contamination effects and instrument saturation

This study characterizes Mars's magnetospheric and ionospheric response to the disappearing solar wind event in December 2022

During the event, open and closed field lines extend beyond the nominal bow shock location, just as the planetary cold ions

The ionospheric ambipolar potential drop is enhanced from the nominal ∼ −0.7 to ∼ −2 V, likely facilitating the ionosphere expansion

An all-sky imaging transient search with the OVRO-LWA detected 5 meteor radio afterglows (MRAs)

The radio emission was resolved through imaging and their spectral index maps were created

The unpolarized nature of the resolved emission favors resonant transition radiation as the emission mechanism of MRAs

The Martian magnetotail exhibits complex morphology and topology downstream of strong crustal magnetic field sources

Multiple magnetic field rotations on spatial scales that are small compared to the magnetotail dimensions suggest multiple current regions

Rare counter-streaming electrons, are twice as likely to occur downstream of crustal fields when they are located near the dusk terminator

Statistical analysis of ultra-low frequency waves shows anti-sunward propagation in the dayside magnetosphere

Enhanced solar wind conditions lead to the enhancement of low-m wave in the dayside and both low- and high-m waves in the nightside

Substorm activity may be an important source of high-m waves in the inner magnetosphere especially in the nightside

Performance of the Robinson and Galand formulas with the input of Defense Meteorological Satellite Program (DMSP) measurements is evaluated during different auroral conditions

Robinson formulas with the DMSP data underestimate the conductances for electron precipitation

Using Galand formulas for ions together with Robinson formulas for electrons improves the conductance estimates for dusk diffuse precipitation

A field-aligned current model for Mercury has been created to complement existing models

Mercury’s field-aligned currents are small in amplitude and extend over a wide range of latitudes and local times

Accounting for field-aligned currents reduces the root-mean-square magnetic field residuals only modestly when compared with prior models

Variations of the EIA crest latitude in the east Asian sector are analyzed with TEC data and TIEGCM simulation

EEJ intensity and northern EIA crest latitude have a good linear relationship but might be attributed to F-region meridional wind effect

Wind effect on the EIA evolution cannot be neglected on an annual timescale

Long-term variations of semidiurnal and terdiurnal tides are systematically investigated from a global perspective

Migrating tides show strong terannual oscillations (TAO) especially in meridional wind, whereas nonmigrating tides do not show obvious TAO

The responses of semidiurnal and terdiurnal tides to the stratospheric quasi-biennial oscillation/solar cycle share similar patterns

Daytime low latitude E region field-aligned irregularities (FAIs) are exclusively linked with sporadic E (Es)

FAIs are linked with eastward neutral wind and their drifts are predominantly eastward

Es parameters are closely related to the vertical shear in the zonal drift of the FAIs

First demonstration of TIDs partially modulating Farley Buneman (FB) and Gradient Drift (GD) waves

Farley Buneman and Gradient Drift Instabilities generate NREs

Spearman rank correlation analysis shows that statistically ∼9% of NRE amplitude modulation could be due to the MSTIDs

In addition to the visible emissions, STEVE is also observed in far ultraviolet emissions

The STEVE on 27 March 2008 has a horizontal length up to 2,700 km and a large altitude extension

Estimated O+ ion drift speed for some STEVE events is ∼20 km/s and the ions' kinetic energy is greater than the FUV excitation potential

The new specification model of cis-GEO near-equatorial plasma environment aimed at the surface charging risk assessment is presented

The model covers the energy ranges 1–100 keV for electrons and 50 eV–50 keV for protons

For a given orbital scenario, the model outputs flux percentiles that are expected to be encountered during the mission lifetime

Both paramagnetic and diamagnetic plasmoids exist in the foreshock

The occurrence rate of the foreshock compressive structures increases on highly decelerated solar wind in the foreshock

Velocity inside the structures is deflected from the surrounding foreshock, but deflection inside the plasmoids is very low

A hybrid model qualitatively reproduced the vertical potential drop and field aligned currents in Martian crustal magnetic cusp regions

The vertical electric potential drop is mostly from the Hall electric field as a result of energy input from the downward plasma flow

The vertical electric potential drop decreases with ionospheric ion density and increases with magnetic field strength

The dependence of cusp location on dipole tilt increases with distance from local magnetic noon

The dependence is asymmetric in both MLT and hemisphere as well as IMF B_y

Greater dependence variance is seen for positive dipole tilt away from noon (with Λ multiplied by −1 in the southern hemisphere)

Responses of seasonal variations of global tidal winds to the stratospheric quasi-biennial oscillation (SQBO) and solar cycle are revealed

For each diurnal tide, the modulation of the dominant seasonal variations by the SQBO/solar cycle is similar to that of the annual means

Empirical formulas are given, which well describe the seasonal and interannual variations of dominant diurnal tides in the peak regions

Using observations of bow shock crossings by Time History of Events and Macroscale Interactions during Substorms mission, we investigate the magnetosheath-origin foreshock ions

Foreshock ion density, velocity, phase space density, and distribution shape are consistent with non-adiabatic magnetosheath leakage

Magnetosheath ion field-aligned anisotropy could cause leakage to become a dominant source of foreshock ions

We examine a far magnetotail traversal (∼60 R_E) by ARTEMIS during a period of prolonged northward IMF

ARTEMIS/ESA observes high density plasma ∼60 R_E downtail coincident with high density plasma observed by Cluster/CIS

We interpret these observations as trapped plasma on closed field lines

We present an algorithm concept for remote sensing thermospheric O and N₂, novel in its use of EUV airglow measurements

Comparison to related measurements during conjunctions with ICON FUV, GOLD, and Swarm are favorable

Retrieval results from 2020 indicate cooler atmospheres than those predicted by MSIS

The magnetopause is found to be significantly deformed with the presence of fast-moving cold ions, whose speed can exceed 400 km s⁻¹

The inferred magnetopause deformation amplitude varies from 0.1 to 2.0 R_E

The observed magnetopause deformation prefers to occur under quasi-radial interplanetary magnetic field and fast solar wind conditions

Harmonic structures in EMIC waves coincided with rising tone magnetosonic waves and proton heating

The enhanced proton precipitation contributes to the intensification of subauroral proton arcs

The variation in subauroral proton arc intensity corresponds to changes in SAPS velocity

Chorus waves with very oblique, eastward-oriented $k$ vectors are observed at the westward edge of a plasmaspheric plume

Ray tracing shows chorus wave vectors are affected by steep azimuthal density gradients, with results being consistent with observations

A general criterion is established to determine whether chorus can enter plumes, which reveals that entry is not possible in this case

The magnitude of thermospheric cooling emission strongly depends on the storm’s intensity

Time lag of nitric oxide (NO) cooling emission with respect to Joule heating rate has little dependence on the storm’s intensity

Strong discrepancy is observed between the modeled and measured Joule heating rates

Possible global distribution of chorus waves at Mercury was estimated based on a nonlinear wave growth theory

Nonlinear chorus waves at Mercury can show a clear day–night asymmetric distribution due to differences in convective growth

Energetic electrons can evolve to a pancake-like pitch angle distribution in Mercury’s ring electron current belt by chorus waves

Magnetic flux contents for flux transfer event (FTE) flux ropes are characterized in terms of the toroidal (axial) and poloidal components

The total poloidal flux may correspond to the amount of flux “opened” in the corresponding polar cap region of the ionosphere

Sequential magnetic reconnection between adjacent field lines can inject poloidal flux into the flux rope during its formation process

Analysis of the power spectral density suggests no connection of double slope occurrence rate and irregularity power within certain scales

ROTI data are similar to the integrated power from the PSD but show larger enhancements within the cusp and nightside auroral oval

The strongest B_y fluctuations are found within the cusp. These enhancement may indicate an increase in Poynting flux on km-scales

At dusk and 09–14 MLT with eastward polar electrojet, the northern (southern) FACs are stronger when IMF B_y < 0 (B_y > 0)

At dawn, 21–02 MLT, and 09–14 MLT with westward polar electrojet, the northern (southern) FACs are stronger when IMF B_y > 0 (B_y < 0)

Northern (southern) FACs with eastward electrojet are located at higher latitude for IMF B_y > 0 (B_y < 0), while FACs with westward electrojet show reverse variation

We compare energetic charged particle data with a model to explain pitch angle distributions observed during four Galileo flybys of Callisto

Electron flux drop-outs are shaped by the perturbed fields associated with Callisto's induced field and magnetospheric plasma interaction

Observed ion fluxes can be mainly explained through geometric considerations, with Callisto's surface shadowing particles from detection

The disturbed magnetic field occurrence probability is derived from Swarm measurements in the polar regions and investigated statistically

Low-frequency distributions evince a persistent dawn-dusk asymmetry, peaking at dawn, similar to auroral electron precipitation

The disturbed magnetic field occurrence probability could, like auroral precipitation observations, be used to infer magnetospheric dynamics

A method for inferring equatorial wave power gain from low altitude electron flux measurements based on quasi-linear theory is described

The inferred chorus wave power gain increases roughly linearly with equatorial 180–300 keV trapped electron flux during moderate storms

Inferred chorus wave power gains typically reach 10 near the upper flux limit

We evaluate the impacts of gravity waves on the non-thermal escape of oxygen on Mars for the first time

Gravity waves can alter local oxygen escape probabilities for some conditions yet have little effect for the average condition

Gravity waves are able to enhance oxygen by ∼20% primarily via enhancing hot oxygen production

1,242 intervals in which Mercury Surface, Space Environment, Geochemistry and Ranging observed the southern lobe of Mercury were identified in 4 years of orbital data

The lobe field strength (in nT) falls off with distance downtail according to B_lobe(r) = (135 ± 8) * r^{(−2.1±0.3)} + (31 ± 8)

Orbit-to-orbit variability in lobe field strength is directly attributable to changing upstream solar wind dynamic pressure

We discuss two approaches to incorporate resonant effects into test particle simulation models

Detailed approaches have been shown for continuous stochastic differential equations (SDEs) and the mapping technique, respectively

In contrast to continuous SDE, the mapping technique allows one to simulate nonlinear resonant effects

A mid-latitude peak is present in total electron content, F layer peak density, and in situ plasma density during the storm recovery phase

The mid-latitude peak covers 40°–150°E in longitude with a noticeable equatorward motion and slight westward shift

The peak structure may be associated with the thermospheric equatorward wind, composition change, and subauroral polarization stream