Dune aurora is an intriguing phenomenon recently discovered thanks to citizen science. It is a dim, diffuse auroral form exhibiting wave-like stripes of brighter emission. We carry out the first statistical study of dune aurora, using 308 observation reports submitted to the Skywarden database by citizen scientists from Europe, North America, and Oceania. We find that dunes are an evening phenomenon, most often reported in March and October and associated with currents in the auroral atmosphere.

Heliophysics spans a wide range of disciplines covering the study of the Sun and the different Solar System bodies, such as Earth and other planets, moons, comets, and asteroids, and their interactions with the Sun, focusing on plasma and atmospheric processes. A grass-roots effort has been recently started toward establishing a European Heliophysics Community (https://www.heliophysics.eu/). This white paper outlines the motivation, priorities, and a future vision of Heliophysics in Europe.

We studied the first broad band emissions, called continuum, in the dayside aurora. They are similar to Strong Thermal Emission Velocity Enhancement (STEVE) with white-, pale-pink-, or mauve-coloured light. But unlike STEVE, they follow the dayside aurora forming rays and other dynamic shapes. We used ground optical and radar observations and found evidence of heating and upwelling of both plasma and neutral air. This study provides new information on conditions for continuum emission, but its understanding will require further work.

We carried out a citizen science study of aurora sightings and technological disruptions experienced during the extreme geomagnetic storm of 10 May 2024. We collected reports from 696 observers from over 30 countries via an online survey, supplemented with observations logged in the Skywarden database. We found that the aurora was seen from exceptionally low latitudes and had very bright red and pink hues, suggesting that high fluxes of low-energy electrons from space entered the atmosphere.

Auroral displays typically take place at high latitudes, but the exact latitude where the auroral breakup occurs can vary. In this study, we compare the characteristics of the fluxes of precipitating electrons from space during auroral breakups occurring above Tromsø (central part of the auroral zone) and above Svalbard (poleward boundary of the auroral zone). We find that electrons responsible for the aurora above Tromsø carry more energy than those precipitating above Svalbard.