High-frequency electrostatic waves are observed in the dip region ahead of the DF

These high-frequency waves are quasi-parallel propagating, and their parallel components dominate

Linear dispersion analysis proves that these waves are excited by the positive slope of the field-aligned electron distribution function

High temporal Resolution Rate-Of-TEC Index (HR-ROTI) is introduced to characterize strong E_s irregularity structure with scale sizes down to a few kilometers

Strong E_s over China tends to occur more frequently around 30°N, and be embedded with ∼2-5 small-scale irregularity structures in one larger structure

The occurrence rates of amplitude scintillations under strong E_s (with HR-ROTI>0.1 TECU/min) at middle and low latitudes are 37% and 12%, respectively

Flare-induced conductivity enhancement, which is dominant over the decrease of eastward electric fields, causes an increase in global daytime currents

E-region conductivity enhancement decreases the ratio between integrated wind-driven currents and conductance and reduces electric fields

The conductance enhancement tends to induce westward electric fields and equatorial counter electrojets in the early morning

The innermost plasmapause location remains the innermost limit of the initial sudden enhancements of energetic electrons

Sudden enhancements observed near the duskside are often found inside the in-situ plasmapause but still beyond the innermost plasmapause

Our findings fit into the understanding of the effect of large-scale electric fields on energetic electrons and the plasmasphere

The leading edges of classic hot flow anomalies move along the normal direction of the driving tangential discontinuities

Seventy-four percent of the spontaneous hot flow anomalies propagate quasi-perpendicular to the background magnetic field

Most spontaneous hot flow anomalies are contracting, and no expanding spontaneous hot flow anomalies are found

Ionospheric irregularity speed is inferred from high resolution dual-frequency measurements using a single GPS receiver at high latitudes

Probability densities of inferred ionospheric irregularity speeds from GPS and radar are statistically compared in both hemispheres

Chorus waves tend to be incoherent when the spatial extent is greater than 433 km or the time lag lasts 10 s at L<∼6.5

The spatial scale size of chorus wave is relatively larger near noon or with lower geomagnetic activity

The temporal scale size of chorus wave is always statistically near zero, not influenced by L-shell, MLT, or AL* index

The first contemporaneous measurements of Q2DW winds and the topside ionospheric response are reported based on ICON data

Q2DW topside F-region field-aligned and meridional drifts of order ±25 ms⁻¹ and ±5-7 ms⁻¹, and electron density (Ne) perturbations of order ±10-25% occurred

ICON winds, drifts, Ne, and ground-based radar-measured winds contain signatures of Q2DW-tide nonlinear interactions

Global mapping of Mercury’s cross-tail current sheet reveals a dominantly bifurcated structure

The current sheet structure is stable against long-period ( 10 hours) variations in magnetospheric and external conditions

The structure is consistent with planetary sodium ions as the primary current carriers in the near-tail region and protons in the far-tail

New Jicamarca ISR topside measurements of the 2019-2020 solar minimum are presented

ISR comparison with DMSP and with ICON for first time at very low solar flux shows consistent results and provides insight into predawn heating

Comparisons between ISR and SAMI2-PE model outputs reveals new insight into composition and energetics of topside

A Chandra ACIS observation reveals a 10.3 sigma detection of X-rays from Uranus with a probability of chance occurrence of 10⁻⁶–10⁻⁷

Uranus' X-rays are concentrated between 0.6 and 1.1 keV, consistent with emission observed from Jupiter and Saturn

The X-ray fluxes seem to exceed scattered solar emission alone, which may suggest X-ray aurora and/or X-ray fluorescence from the rings