Quantifying the Energy Budget in the Solar Wind from 13.3 to 100 Solar Radii
AuthorHalekas, J. S.
Bale, S. D.
Chandran, B. D. G.
Drake, J. F.
Kasper, J. C.
Klein, K. G.
Larson, D. E.
Pulupa, M. P.
Stevens, M. L.
Verniero, J. L.
AffiliationLunar and Planetary Laboratory, University of Arizona
MetadataShow full item record
PublisherAmerican Astronomical Society
CitationJ. S. Halekas et al 2023 ApJ 952 26
JournalThe Astrophysical Journal
Rights© 2023. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at email@example.com.
AbstractA variety of energy sources, ranging from dynamic processes, such as magnetic reconnection and waves, to quasi-steady terms, such as plasma pressure, may contribute to the acceleration of the solar wind. We utilize a combination of charged particle and magnetic field observations from the Parker Solar Probe (PSP) to attempt to quantify the steady-state contribution of the proton pressure, the electric potential, and the wave energy to the solar wind proton acceleration observed by PSP between 13.3 and ∼100 solar radii (R☉). The proton pressure provides a natural kinematic driver of the outflow. The ambipolar electric potential acts to couple the electron pressure to the protons, providing another definite proton acceleration term. Fluctuations and waves, while inherently dynamic, can act as an additional effective steady-state pressure term. To analyze the contributions of these terms, we utilize radial binning of single-point PSP measurements, as well as repeated crossings of the same stream at different distances on individual PSP orbits (i.e., fast radial scans). In agreement with previous work, we find that the electric potential contains sufficient energy to fully explain the acceleration of the slower wind streams. On the other hand, we find that the wave pressure plays an increasingly important role in the faster wind streams. The combination of these terms can explain the continuing acceleration of both slow and fast wind streams beyond 13.3 R.
NoteOpen access journal
VersionFinal published version
SponsorsNational Aeronautics and Space Administration
Except where otherwise noted, this item's license is described as © 2023. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence.