AUTHOR=Kajdič Primož , Blanco-Cano Xóchitl , Turc Lucile , Archer Martin , Raptis Savvas , Liu Terry Z. , Pfau-Kempf Yann , LaMoury Adrian T. , Hao Yufei , Escoubet Philippe C. , Omidi Nojan , Sibeck David G. , Wang Boyi , Zhang Hui , Lin Yu 

TITLE=Transient upstream mesoscale structures: drivers of solar-quiet space weather

JOURNAL=Frontiers in Astronomy and Space Sciences

VOLUME=Volume 11 - 2024

YEAR=2024

URL=https://www.frontiersin.org/journals/astronomy-and-space-sciences/articles/10.3389/fspas.2024.1436916

DOI=10.3389/fspas.2024.1436916

ISSN=2296-987X

ABSTRACT=In recent years, it has become increasingly clear that space weather disturbances can be triggered by transient upstream mesoscale structures (TUMS), independently of the occurrence of large-scale solar wind (SW) structures, such as interplanetary coronal mass ejections and stream interaction regions. Different types of magnetospheric pulsations, transient perturbations of the geomagnetic field and auroral structures are often observed during times when SW monitors indicate quiet conditions, and have been found to be associated to TUMS. In this mini-review we describe the space weather phenomena that have been associated with four of the largest-scale and the most energetic TUMS, namely, hot flow anomalies, foreshock bubbles, travelling foreshocks and foreshock compressional boundaries. The space weather phenomena associated with TUMS tend to be more localized and less intense compared to geomagnetic storms. However, the quiet time space weather may occur more often since, especially during solar minima, quiet SW periods prevail over the perturbed times.