Recent  

The Super Typhoon Kong-Rey maximum energy release is clearly observed in the 2,800–3,300 km range. The quasi-sinusoidal perturbations in the electron density exhibit variability in the ~20–120 min period range, within which the amplitude of the electron density increases from a few to several tens of per cent, and which means that they are due to atmospheric gravity waves excited by the typhoon. The dusk terminator and super typhoon act synergistically to amplify the ionospheric response.

Magnetic holes are curious localized dropouts of magnetic field strength in the solar wind (the flow of ionized gas continuously streaming out from the sun). In this paper we show that these magnetic holes can cross the bow shock (where the solar wind brake down to subsonic velocity), and enter the region close to Earth’s magnetosphere. These structures may therefore represent a new type of non-uniform solar wind-magnetosphere interaction.

The ionospheric satellite signals during geomagnetic storms can severely threaten navigation accuracy. We analyzed vertical Total Electron Content (vTEC) variations from the Global Navigation Satellite System at different latitudes around the world during the geomagnetic storms of June 2015 and August 2018. We also analyzed the vTEC from the Swarm satellites and found similar results to the GNSS retrieved vTEC during different phases of both geomagnetic storms.

We measured the height of green and blue aurora using thousands of camera images recorded over a 7 year period. Both colours are typically brightest at about 114 km altitude. When they peak at higher altitudes the blue aurora is usually higher than the green aurora. This information will help other studies which need an estimate of the auroral height. We used a computer model to explain our observations and to investigate how the green aurora is produced.

In this paper, the solar radiation index Y10 acts as an indicator of the solar activity, and the vertical column of ice water content (IWC) characterizes the nature of the polar mesosphere cloud (PMC). Superposed epoch analysis is used to determine the time lag days of temperature and IWC anomalies in responding to Y10 for the PMC seasons from 2007–2015. The results show that the IWC can respond quickly to temperature within time lag of one day.

We have examined events during which the measured magnetic field on the ground changes very rapidly, causing a risk to technological conductor networks. According to our results, such events occur when strong electric currents in the ionosphere at 100 km altitude are abruptly modified by sudden compression or expansion of the magnetospheric magnetic field farther in space.

Through the statistical analysis of potential plasmaspheric plume, we find that there is almost no correlation between plume width and the intensity of geomagnetic storms. However, for the plumes in the recovery phase after improved sifting, there is a negative correlation between the plume width and the absolute value of minimum Dst duringstorm. We suggest that the plasmaspheric particles may escape quickly during intense storms, causing plume to be relatively narrow during the recovery phase.

Collisional fragmentation of asteroids, comets and meteoroids result in the formation of dust in the solar system. The dust distribution is however uncharted and the role of dust in the solar system is largely unknown. At present, the solar system is explored by the Solar Orbiter spacecraft. We present a novel method, based on artificial intelligence, that can be used for detecting when dust particles impact the Solar Orbiter with high accuracy, making it possible to study the dust distribution.