Gravity waves (GWs) are waves in Earth's atmosphere and can be observed as cloud ripples. Under certain conditions, these waves can propagate up into the ionosphere. Here, they can cause ripples in the ionosphere plasma, observable as oscillations of the plasma density. Therefore, GWs contribute to the ionospheric variability, making them relevant for space weather prediction. Additionally, the behavior of these waves allows us to draw conclusions about the atmosphere at these altitudes.

Temperatures at 85 km around Earth's poles in summer can be so cold that small ice particles form. These can become charged, and, combined with turbulence at these altitudes, they can influence the many electrons present. This can cause large radar echoes called polar mesospheric summer echoes. We use radio waves to heat these echoes on and off when the sun is close to or below the horizon. This allows us to gain some insight into these ice particles and how the sun influences the echoes.

Collisional fragmentation of asteroids, comets and meteoroids is the main source 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 interplanetary medium is explored by the Solar Orbiter spacecraft. We present a novel method, based on artificial intelligence, that can be used for detecting dust impacts in Solar Orbiter observations with high accuracy, advancing the study of dust in the solar system.

We have investigated the nucleation process of noctilucent clouds observed in the mesosphere using a theoretical approach, where we adopt a more accurate model called the semi-phenomenological model for the nucleation process. We obtained an important result that rejects one of the two dominant nucleation mechanisms that have been proposed. Our results show it is extremely difficult for homogeneous nucleation of water to occur in the mesosphere, while heterogeneous nucleation occurs effectively.

Our model calculations indicate that meteoric smoke particles (MSPs) influence both the magnitude and shape of the electron temperature during artificial heating. Others have found that current theoretical models most likely overestimate heating in the D-region compared to observations. In a future study, we will compare our results to observations of the electron temperature during heating to investigate if the presence of MSPs can explain the discrepancy between model and observations.

This paper discusses the charge generation for impacts of nano- to micro-scale dust on metal surfaces at speeds below a few kilometres per second. By introducing a model of capacitive coupling between the dust and the impact surface, we find that at such low speeds, the charge can be dominated by contact charging as opposed to plasma generation.