EM emissions produced by a collision between two sprite streamers with opposite polarities are predicted using streamer and antenna models.

Calculated radiated power from these EM emissions is compared to DEMETER, TARANIS, and FORTE radio instruments sensitivities.

Sensitive ground-based instruments such as radiotelescopes (e.g., NenuFAR) may detect these emissions.

Large increase in the occurrence of post-midnight radar echoes in September 2019, when there is austral polar stratospheric warming event

Relative dominance of SW2 tidal amplitudes over DW1 tidal amplitudes due to accumulation of ozone in the equatorial stratosphere

Suppression of DW1 is due to its interaction with planetary waves and semi-diurnal character in zonal electric field can cause radar echoes

Coincident ICON measurements of neutral winds, plasma drifts and total ion densities (\coloneq Ne) are analyzed during January 1-21, 2020.

We show for the first time that PW winds modulate DE3 and produce longitudinal wave-4 variations in F-region vertical drifts ∼±10 ms⁻¹, Ne ∼±30%.

Measured F-region wave-4 winds suggest that SPW4, SE2 & DW5 arising from tide-tide and tide-ion drag interactions also contribute to Ne variability.

D-region electron density estimation

Trans-ionospheric VLF propagation

Direction and magnitude of horizontal winds below 110 km affect MILs because MILs lag behind the wind shear null, where wind velocity is 0.

The sporadicity of MILs is attributed to the horizontal transportation of their 3-D structures.

Around Japan, vertical winds can modify the structures of MILs below 100 km.

The re-reconnection between two flux ropes results in a transformation of free field lines into semi-open field lines.

The re-reconnection between a flux rope and cusp field lines produces more semi-open field lines, and the flux rope can break into two short ones.

The two re-reconnection processes favor particle/energy transport towards Earth’s magnetosphere, which may affect additional auroral signatures, such as poleward moving aurora forms.

Channels for conversion of turbulent energy into internal energy. i.e., dissipation, are investigated using MMS data in the terrestrial magnetosheath.

An ensemble of 50 magnetosheath turbulent intervals is identified and analyzed, in terms of compressive and incompressive channels, and divided into quasi-parallel and quasi-perpendicular bow shock types.

Both heating and cooling intervals are found for both compressive and incompressive channels; the distribution of values in the compressive channel is closer to gaussian.

EMIC waves in the magnetosphere have four major occurrence regions excited by possibly different generation processes.

For He-EMIC waves in the afternoon sector, injected particles and off-equatorial sources are the major driver at L∼6 and L>8, respectively.

H-EMIC waves are generated by enhancing dynamic pressure in the noon sector at L<6, or suprathermal protons in the dawn sector at L>8.

We strategically coordinate measurements made by THEMIS and LANL spacecraft, GPS network, and SuperDARN to investigate geospace plumes.

Plumes decrease the local reconnection rate at the plume longitude and increase the reconnection rate in regions adjacent to the plume.

When the solar wind is stable, the global reconnection remains unchanged in presence of plumes, supporting a global-control theory.

The MMS spacecraft observe two fully developed foreshock bubbles whose properties are compared with the predictions of the hybrid code model

A global hybrid simulation predicts the characteristics of two foreshock bubbles in the region upstream from the bow shock

The simulation results match MMS observations of the two FBs, but uncertainties associated with solar wind conditions need to be considered

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