Interplay Between a Foreshock Bubble and a Hot Flow Anomaly Forming Along the Same Rotational Discontinuity
Year: 2025
Type: article
Abstract: Solar wind directional discontinuities can generate transient mesoscale structures such as foreshock bubbles and hot flow anomalies (HFAs) upstream of Earth's bow shock. These structures can have a global impact on near‐Earth space, so understanding their formation conditions is essential. We investigate foreshock transient generation at a rotational discontinuity using a global 2D hybrid‐Vlasov simulation. As expected, a foreshock bubble forms on the sunward side of the discontinuity. Later, when the discontinuity reaches the shock, new structures identified as HFAs develop, despite the initial discontinuity not being favorable to HFA formation. We demonstrate that the foreshock bubble provides the necessary conditions for their generation. We then investigate the evolution of the transient structures and the large‐scale bow shock deformation they induce. Our results provide new insights on the formation and evolution of foreshock transients and their impact on the shock.
Source: Geophysical Research Letters
DOI: 10.1029/2025gl116473
Institutions: University of Helsinki, Imperial College London, Boston University, CSC - IT Center for Science (Finland), Universidad Nacional Autónoma de México, Johns Hopkins University Applied Physics Laboratory, University of California, Los Angeles, Shandong University, European Space Research and Technology Centre, Chinese Academy of Sciences, Purple Mountain Observatory, Finnish Meteorological Institute
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,190
Funders: Helsingin Yliopisto, UK Research and Innovation, European Commission, Academy of Finland, Johns Hopkins University Press, Dirección General de Asuntos del Personal Académico, Universidad Nacional Autónoma de México, HORIZON EUROPE European Research Council, Centro de Ingeniería y Desarrollo Industrial
Awards: G153683194, Centre of Excellence in Research of Sustainable Space, G3057166759, G3109284379, Kinetic Ionosphere–Magnetosphere Coupling with Hybrid Ions (KIMCHI), Impact of foreshock transients on near-Earth space, Fast AI-assisted Space Environment pRediction, Finnish Centre of Excellence in Research of Sustainable Space, G5257050126, G5428434477, G7051430717, G7303702510
OpenAlex ID: W4411236542