1,1,2,3,8,1,1,8,11,- 1INAF - Institute for Space Astrophysics and Planetology, Rome, Italy (omkar.dhamane@inaf.it)
- 2Department of Mathematics, Physics and Electrical Engineering, Northumbria University, Ellison Place, Newcastle Upon Tyne, NE1 8ST, UK
- 3Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain
- 4Istituto per la Scienza e la Tecnologia dei Plasmi, Consiglio Nazionale delle Ricerche, Bari, Italy
- 5Space and Plasma Physics, School of Electrical Engineering and Computer Science, KTH Royal Institute of Technology, Stockholm, Sweden
- 6INAF - Osservatorio Astrofisico di Torino, Torino, Italy
- 7ASI - Italian Space Agency, Rome, Italy
- 8University College London, Mullard Space Science Laboratory, Holmbury St. Mary, Dorking, Surrey, RH5 6NT, UK
- 9IRAP, Toulouse, France
- 10Southwest Research Institute, San Antonio, TX, USA
- 11Department of Physics, University of Mumbai, Mumbai, India
- 12Center of Excellence in Space Sciences India, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, West Bengal, India
- 13Indian Institute of Geomagnetism (IIG), Kalamboli, New Panvel, Navi Mumbai, 410218, India
Alfvénic fluctuations are a ubiquitous, particularly in fast streams, whereas the slow wind is typically characterized by reduced Alfvénicity and enhanced variability. However, the slow wind can display strongly Alfvénic behavior as well, with fluctuation properties comparable to those of fast streams, challenging the traditional fast–slow wind dichotomy.
In this study, we perform a comparative analysis of fast solar wind and Alfvénic slow wind during the October 2022 perihelion. In particular, we investigate the solar source and the turbulent properties of the different solar wind regimes, using plasma and magnetic field measurements from the Solar Wind Analyser (SWA) and Magnetometer (MAG) instruments onboard Solar Orbiter. We further investigate possible connections between large-scale turbulence properties and small-scale dissipation by examining the relationship between inertial-range fluctuations and magnetic-field polarization at ion scales across the spectral break. By combining in situ observations with remote-sensing data and two-step ballistic backmapping, we show that Solar Orbiter was magnetically connected to the coronal hole has a bright structure within it, indicating that the observed solar wind variability is driven by spatio-temporal changes in magnetic connectivity to coronal source. Our results show that Alfvénic slow-wind interval preserve a high degree of Alfvénicity, as evidenced by large normalized cross helicity, near kinetic–magnetic energy equipartition, low magnetic compressibility, and large-amplitude magnetic and velocity fluctuations comparable to those observed in fast Alfvénic streams, despite their lower bulk speeds and higher Coulomb collisional age. These findings pose significant challenges for solar-wind models, which must account for the persistence of strong Alfvénic turbulence in slow wind originating from nearby and evolving coronal source regions while exhibiting markedly different bulk plasma properties.
How to cite: Dhamane, O. S., D'amicis, R., Benella, S., Yardley, S., De marco, R., Bruno, R., Sorriso-Valvo, L., Telloni, D., Perrone, D., Owen, C., Louarn, P., Livi, S., Raghav, A., Kumbhar, K., Sharma, U., Kadam, S., and naik, U.: Characterization of Multiple Alfvénic Solar Wind Regimes Observed by Solar Orbiter at the October 2022 Perihelion, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-11085, https://doi.org/10.5194/egusphere-egu26-11085, 2026.
