Abstract

Small-scale eruptions are ubiquitous in the solar atmosphere. With different sizes and dominant temperatures, these eruptions are observed at different wavelengths and have been given various names including spicules, macro-spicules, micro-jets, jets, X-ray bright-points, campfires, etc. These small-scale eruptions are often accompanied or associated with small-scale dynamic solar magnetic phenomena.

While they were first observed in the late 19th century, our knowledge of these eruptive phenomena has greatly improved in the last few decades. This was possible thanks to the parallel developments of MHD and plasma-astrophysics theories, the improvement in computational modelling, and the advent of state-of-the-art observatories with broad wavelength coverage and high resolution in the spatial, spectral, and temporal domains.

However, key details about the origin and impact of these eruptive phenomena in the heliosphere are still not understood. For example, what drives and sets the different scales of jets, how much energy and mass transport they can contribute to, and how they are related to the solar wind.

We will address this problem using an unprecedented combination of multi-messenger space observations (SDO, IRIS, ASO-S, PSP, and Solar Orbiter), complemented by state-of-the-art numerical models and the highest resolution ground-based observations (e.g., DKIST, BBSO, SST, NVST, and AIMS), many of which have only just become available. Our multi-disciplinary team is uniquely suited to address small-scale eruptions in the solar atmosphere, and we expect to make a significant contribution to the understanding of their underlying formation, transmission, and dissipation mechanisms.