arXiv subjects

Maosheng He

Publications and source records attributed to Maosheng He.

3 recordsLinked to original sources

arXiv2026

Reassessment of Ionospheric Responses to GRB~221009A: Disentangling Instrumental, Illumination and Geophysical Effects

Gamma-ray bursts (GRBs) have long been proposed to perturb Earth's ionosphere, with occasional reports of disruptions in ultra- and extremely-low-frequency radio signals. The exceptionally bright GRB~221009A was recently claimed to induce multi-altitude ionospheric responses, including perturbations in satellite electric fields, regional total electron content (TEC), and the equatorial electrojet (EEJ). These claims have renewed interest in the potential near-Earth impacts of astrophysical transients. Here we perform an independent reassessment using expanded datasets spanning multiple altitudes. We find no coherent, burst-like TEC enhancement, show that the reported electric-field anomalies recur under specific illumination conditions each orbit, and demonstrate that the EEJ fluctuations preceded the burst and coincide with solar-wind variability. Together, these results indicate that the reported GRB-induced ionospheric responses are fully attributable to other natural geophysical processes and instrumental artefacts, thereby resolving a high-profile controversy and clarifying the true limits of GRBs'ionospheric effects.

physics.space-ph↗

arXiv2024

Nonlinear Interactions of Planetary-Scale Waves in Mesospheric Winds Observed at 52°N Latitude and Two Longitudes

Nine years of mesospheric wind data from two meteor radars at 52°N latitude were analyzed to investigate planetary waves (PWs) and tides by estimating their zonal wavenumber through longitudinal phase differences. Our results reveal that PW normal modes (NMs) primarily drive multi-day oscillations, showing seasonal variability and statistical associations with Sudden Stratospheric Warming (SSW) events. Specifically, a significant 6-day NM emerges in April, followed by predominant 4- and 2-day NMs until June, with peaks of 2-, 4-, and 6-day NMs spanning July to October. Furthermore, our study provides the first observational verification of frequency and zonal wavenumber of over ten secondary waves from nonlinear interactions among planetary-scale waves. One notable finding is the prevalence of non-migrating components in winter 24-hour and summer 8-hour tides, attributed to these nonlinear interactions. Our findings underscore the diverse nonlinear dynamics of planetary-scale waves, triggering a variety of periodic oscillations.

physics.space-ph↗

arXiv2021

Spatially high-resolved solar-wind-induced magnetic field on Venus

The current work investigates the Venusian solar-wind-induced magnetosphere at a high spatial resolution using all Venus Express (VEX) magnetic observations through an unbiased statistical method. We first evaluate the predictability of the interplanetary magnetic field (IMF) during VEX's magnetospheric transits, and then map the induced field in a cylindrical coordinate system under different IMF conditions. Our high-resolution mapping enables resolving structures on various scales, ranging from the thin ionopause and the associated electric currents to the classical global-scale draped IMF. Our mapping also resolves two recently-reported structures, a low ionospheric magnetization over the terminator and a global "looping" structure in the near magnetotail, both of which are not depicted in the classical draping configuration. In contrast to the reported IMF-independent cylindrical magnetic field of both structures, our results illustrate their IMF dependence. In both structures, the cylindrical magnetic component is stronger in the hemisphere with an upward solar wind electric field ($E^{SW}$) than in the opposite hemisphere. Under downward $E^{SW}$, the "looping" structure even breaks, which is attributable to an additional draped magnetic field structure wrapping toward $-E^{SW}$. In addition, our results suggest that these two structures are spatially not overlapping with each other. The low ionospheric structure occurs in a very narrow region, at about 87--95$^\circ$ solar zenith angle and 190--210~km altitude, implying that future simulation to reproduce the structure entails at least a spatial resolution of about 10 km. We discuss this narrow structure in terms of a Cowling channel.

physics.space-ph↗