Measured energy exchange in coronal hole solar wind from its solar origins to the heliosphere

Yeimy J. Rivera; Alin R. Paraschiv; Samuel T. Badman; Alberto M. Vasquez; Federico A. Nuevo; Ryan J. French; Momchil Molnar; Roberto Susino; Zihao Yang; Marco Romoli; Richard A. Frazin; Michael L. Stevens; Stuart D. Bale; Deborah Baker; Jasper Halekas; Thomas A. Schad; Christopher J. Owen; Philippe Louarn; Jenna Samra; Giuliana de Toma; Daniela A. Lacatus; Giulio Del Zanna; Chad A. Madsen; Enrico Landi; Manolis K. Georgoulis; Amir Caspi; Éric Buchlin; Nour E. Raouafi; Luca Franci; Miho Janvier; Cooper Downs; Roberto Livi; Phyllis Whittlesey; Ali Rahmati; Davin Larson; Nikos Sioulas

arXiv · 2610.04669

Measured energy exchange in coronal hole solar wind from its solar origins to the heliosphere

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Abstract

Coordinated ground- and space-based remote observations are used to provide a comprehensive, multi-perspective view of the solar atmosphere that we connect with in situ measurements in the heliosphere centered around the April 8 2024 Total Solar Eclipse observed across North America. These near-contemporaneous, multi-wavelength datasets are used to directly derive the plasma parameters and compute an energy budget of a solar wind stream at its low-coronal birthplace (at an altitude of 1.05Rsun). The energy budget is also independently computed at and beyond the Alfvén surface from the in situ observations of the same stream. The total wave energy flux dominates the low-coronal budget (11 W m-2 Alfvén, 7 to 23 W m-2 in compressive MHD modes), while enthalpy (13 W m-2) and work done against gravity from 1.0Rsun (2.5 W m-2) make up the remainder. The total coronal energy budget is consistent with the total measured in situ by Parker Solar Probe if and only if compressive energy flux is included and attributed to the fast magnetosonic mode. Nearly all this thermal and wave energy is converted to ion heating, acceleration and gravitational potential energy within the Alfvén surface. The stream evolution is well-described as a thermal-pressure driven wind with additional energy deposited by MHD fluctuations. The observed evolution of the Alfvénic component of these fluctuations follows a near-dissipation-free curve below the Alfvén surface while deviating from it more strongly above this critical surface.

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Yeimy J. Rivera, Alin R. Paraschiv, Samuel T. Badman, Alberto M. Vasquez, Federico A. Nuevo, Ryan J. French, Momchil Molnar, Roberto Susino, Zihao Yang, Marco Romoli, Richard A. Frazin, Michael L. Stevens, Stuart D. Bale, Deborah Baker, Jasper Halekas, Thomas A. Schad, Christopher J. Owen, Philippe Louarn, Jenna Samra, Giuliana de Toma, Daniela A. Lacatus, Giulio Del Zanna, Chad A. Madsen, Enrico Landi, Manolis K. Georgoulis, Amir Caspi, Éric Buchlin, Nour E. Raouafi, Luca Franci, Miho Janvier, Cooper Downs, Roberto Livi, Phyllis Whittlesey, Ali Rahmati, Davin Larson, Nikos Sioulas. 2026-10-03. Measured energy exchange in coronal hole solar wind from its solar origins to the heliosphere. https://arxiv.org/abs/2610.04669

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