Exploring the Solar Wind from Its Source on the Corona into the Inner Heliosphere during the First Solar Orbiter–Parker Solar Probe Quadrature
Daniele Telloni, V. Andretta, E. Antonucci, А. Бемпорад, G. Capuano, Silvano Fineschi, S. Giordano, S. R. Habbal, Denise Perrone, Rui Pinto, L. Sorriso‐Valvo, D. Spadaro, Roberto Susino, L. D. Woodham, G. P. Zank, M. Romoli, S. D. Bale, J. C. Kasper, F. Auchère, R. Bruno, Gerardo Capobianco, A. W. Case, C. Casini, Marta Casti, Paolo Chioetto, Alain Jody Corso, Vania Da Deppo, Yara De Leo, Thierry Dudok de Wit, F. Frassati, Fabio Frassetto, K. Goetz, S. L. Guglielmino, P. Harvey, P. Heinzel, G. Jerse, K. E. Korreck, Federico Landini, D. E. Larson, Alessandro Liberatore, R. Livi, R. J. MacDowall, Enrico Magli, D. Malaspina, G. Massone, M. Messerotti, J. D. Moses, G. Naletto, G. Nicolini, Giuseppe Nisticó, O. Panasenco, M. Pancrazzi, Maria Guglielmina Pelizzo, M. Pulupa, F. Reale, P. Romano, C. Sasso, U. Schühle, M. Stangalini, M. L. Stevens, L. Strachan, T. Straus, L. Teriaca, M. Uslenghi, M. Velli, Daniel Verscharen, A. Volpicelli, P. L. Whittlesey, L. Zangrilli, G. Zimbardo, Paola Zuppella
Abstract
Abstract This Letter addresses the first Solar Orbiter (SO)–Parker Solar Probe (PSP) quadrature, occurring on 2021 January 18 to investigate the evolution of solar wind from the extended corona to the inner heliosphere. Assuming ballistic propagation, the same plasma volume observed remotely in the corona at altitudes between 3.5 and 6.3 solar radii above the solar limb with the Metis coronagraph on SO can be tracked to PSP, orbiting at 0.1 au, thus allowing the local properties of the solar wind to be linked to the coronal source region from where it originated. Thanks to the close approach of PSP to the Sun and the simultaneous Metis observation of the solar corona, the flow-aligned magnetic field and the bulk kinetic energy flux density can be empirically inferred along the coronal current sheet with an unprecedented accuracy, allowing in particular estimation of the Alfvén radius at 8.7 solar radii during the time of this event. This is thus the very first study of the same solar wind plasma as it expands from the sub-Alfvénic solar corona to just above the Alfvén surface.