The Astrophysical Journal Letters (Jan 2023)
Magnetic Field Spectral Evolution in the Inner Heliosphere
- Nikos Sioulas,
- Zesen Huang,
- Chen Shi,
- Marco Velli,
- Anna Tenerani,
- Trevor A. Bowen,
- Stuart D. Bale,
- Jia Huang,
- Loukas Vlahos,
- L. D. Woodham,
- T. S. Horbury,
- Thierry Dudok de Wit,
- Davin Larson,
- Justin Kasper,
- Christopher J. Owen,
- Michael L. Stevens,
- Anthony Case,
- Marc Pulupa,
- David M. Malaspina,
- J. W. Bonnell,
- Roberto Livi,
- Keith Goetz,
- Peter R. Harvey,
- Robert J. MacDowall,
- Milan Maksimović,
- P. Louarn,
- A. Fedorov
Affiliations
- Nikos Sioulas
- ORCiD
- Department of Earth, Planetary, and Space Sciences, University of California , Los Angeles Los Angeles, CA 90095, USA ; [email protected]
- Zesen Huang
- ORCiD
- Department of Earth, Planetary, and Space Sciences, University of California , Los Angeles Los Angeles, CA 90095, USA ; [email protected]
- Chen Shi
- ORCiD
- Department of Earth, Planetary, and Space Sciences, University of California , Los Angeles Los Angeles, CA 90095, USA ; [email protected]
- Marco Velli
- ORCiD
- Department of Earth, Planetary, and Space Sciences, University of California , Los Angeles Los Angeles, CA 90095, USA ; [email protected]
- Anna Tenerani
- ORCiD
- Department of Physics, The University of Texas at Austin , TX 78712, USA
- Trevor A. Bowen
- ORCiD
- Space Sciences Laboratory, University of California , Berkeley, CA 94720-7450, USA
- Stuart D. Bale
- ORCiD
- Space Sciences Laboratory, University of California , Berkeley, CA 94720-7450, USA; Physics Department, University of California , Berkeley, CA 94720-7300, USA
- Jia Huang
- ORCiD
- Climate and Space Sciences and Engineering, University of Michigan , Ann Arbor, MI 48109, USA
- Loukas Vlahos
- ORCiD
- Department of Physics, Aristotle University of Thessaloniki GR-52124 Thessaloniki, Greece
- L. D. Woodham
- ORCiD
- Department of Physics, The Blackett Laboratory, Imperial College London , London, SW7 2AZ, UK
- T. S. Horbury
- ORCiD
- The Blackett Laboratory, Imperial College London , London, UK
- Thierry Dudok de Wit
- ORCiD
- LPC2E, CNRS and University of Orléans , Orléans, France
- Davin Larson
- ORCiD
- Space Sciences Laboratory, University of California , Berkeley, CA 94720-7450, USA
- Justin Kasper
- ORCiD
- Climate and Space Sciences and Engineering, University of Michigan , Ann Arbor, MI 48109, USA; BWX Technologies, Inc. , Washington, DC 20002, USA
- Christopher J. Owen
- ORCiD
- Mullard Space Science Laboratory, University College London , Dorking, RH5 6NT, UK
- Michael L. Stevens
- ORCiD
- Harvard-Smithsonian Center for Astrophysics , Cambridge, MA 02138, USA
- Anthony Case
- ORCiD
- Smithsonian Astrophysical Observatory , Cambridge, MA 02138, USA
- Marc Pulupa
- ORCiD
- Space Sciences Laboratory, University of California , Berkeley, CA 94720-7450, USA
- David M. Malaspina
- ORCiD
- Astrophysical and Planetary Sciences Department, University of Colorado , Boulder, CO, USA; Laboratory for Atmospheric and Space Physics, University of Colorado , Boulder, CO, USA
- J. W. Bonnell
- ORCiD
- Space Sciences Laboratory, University of California , Berkeley, CA 94720-7450, USA
- Roberto Livi
- ORCiD
- Space Sciences Laboratory, University of California , Berkeley, CA 94720-7450, USA
- Keith Goetz
- ORCiD
- School of Physics and Astronomy, University of Minnesota , Minneapolis, MN 55455, USA
- Peter R. Harvey
- ORCiD
- Space Sciences Laboratory, University of California , Berkeley, CA 94720-7450, USA
- Robert J. MacDowall
- ORCiD
- Solar System Exploration Division, NASA/Goddard Space Flight Center , Greenbelt, MD 20771, USA
- Milan Maksimović
- ORCiD
- LESIA, Observatoire de Paris, Universit e PSL, CNRS, Sorbonne Universit e, Universit e de Paris , 5 place Jules Janssen, F-92195 Meudon, France
- P. Louarn
- ORCiD
- IRAP, Université Toulouse III—Paul Sabatier , CNRS, CNES, Toulouse, France
- A. Fedorov
- ORCiD
- IRAP, Université Toulouse III—Paul Sabatier , CNRS, CNES, Toulouse, France
- DOI
- https://doi.org/10.3847/2041-8213/acaeff
- Journal volume & issue
-
Vol. 943,
no. 1
p. L8
Abstract
Parker Solar Probe and Solar Orbiter data are used to investigate the radial evolution of magnetic turbulence between 0.06 ≲ R ≲ 1 au. The spectrum is studied as a function of scale, normalized to the ion inertial scale d _i . In the vicinity of the Sun, the inertial range is limited to a narrow range of scales and exhibits a power-law exponent of, α _B = −3/2, independent of plasma parameters. The inertial range grows with distance, progressively extending to larger spatial scales, while steepening toward a α _B = −5/3 scaling. It is observed that spectra for intervals with large magnetic energy excesses and low Alfvénic content steepen significantly with distance, in contrast to highly Alfvénic intervals that retain their near-Sun scaling. The occurrence of steeper spectra in slower wind streams may be attributed to the observed positive correlation between solar wind speed and Alfvénicity.
Keywords
