The Astrophysical Journal Letters (Jan 2023)
New Observations of Solar Wind 1/f Turbulence Spectrum from Parker Solar Probe
- Zesen Huang,
- Nikos Sioulas,
- Chen Shi,
- Marco Velli,
- Trevor Bowen,
- Nooshin Davis,
- B. D. G. Chandran,
- Lorenzo Matteini,
- Ning Kang,
- Xiaofei Shi,
- Jia Huang,
- Stuart D. Bale,
- J. C. Kasper,
- Davin E. Larson,
- Roberto Livi,
- P. L. Whittlesey,
- Ali Rahmati,
- Kristoff Paulson,
- M. Stevens,
- A. W. Case,
- Thierry Dudok de Wit,
- David M. Malaspina,
- J. W. Bonnell,
- Keith Goetz,
- Peter R. Harvey,
- Robert J. MacDowall
Affiliations
- Zesen Huang
- ORCiD
- Department of Earth, Planetary, and Space Sciences, University of California , Los Angeles, CA, USA
- Nikos Sioulas
- ORCiD
- Department of Earth, Planetary, and Space Sciences, University of California , Los Angeles, CA, USA
- Chen Shi
- ORCiD
- Department of Earth, Planetary, and Space Sciences, University of California , Los Angeles, CA, USA
- Marco Velli
- ORCiD
- Department of Earth, Planetary, and Space Sciences, University of California , Los Angeles, CA, USA; International Space Science Institute , Bern 3012, CH, Switzerland
- Trevor Bowen
- ORCiD
- Space Sciences Laboratory, University of California , Berkeley, CA 94720-7450, USA
- Nooshin Davis
- ORCiD
- Space Science Center and Department of Physics, University of New Hampshire , Durham, NH 03824, USA
- B. D. G. Chandran
- ORCiD
- Space Science Center and Department of Physics, University of New Hampshire , Durham, NH 03824, USA
- Lorenzo Matteini
- ORCiD
- Imperial College London, South Kensington Campus , London SW7 2AZ, UK
- Ning Kang
- ORCiD
- Department of Atmospheric and Oceanic Sciences, University of California , Los Angeles, CA, USA
- Xiaofei Shi
- ORCiD
- Department of Earth, Planetary, and Space Sciences, University of California , Los Angeles, CA, USA
- Jia Huang
- 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
- J. C. Kasper
- ORCiD
- BWX Technologies , Inc., Washington DC 20001, USA; Climate and Space Sciences and Engineering, University of Michigan , Ann Arbor, MI 48109, USA
- Davin E. Larson
- ORCiD
- Space Sciences Laboratory, University of California , Berkeley, CA 94720, USA
- Roberto Livi
- ORCiD
- Space Sciences Laboratory, University of California , Berkeley, CA 94720, USA
- P. L. Whittlesey
- ORCiD
- Space Sciences Laboratory, University of California , Berkeley, CA 94720, USA
- Ali Rahmati
- ORCiD
- Space Sciences Laboratory, University of California , Berkeley, CA 94720, USA
- Kristoff Paulson
- ORCiD
- Smithsonian Astrophysical Observatory , Cambridge, MA 02138 USA
- M. Stevens
- ORCiD
- Smithsonian Astrophysical Observatory , Cambridge, MA 02138 USA
- A. W. Case
- ORCiD
- Smithsonian Astrophysical Observatory , Cambridge, MA 02138 USA
- Thierry Dudok de Wit
- ORCiD
- LPC2E, CNRS and University of Orléans , Orléans, France
- 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
- 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
- DOI
- https://doi.org/10.3847/2041-8213/acd7f2
- Journal volume & issue
-
Vol. 950,
no. 1
p. L8
Abstract
The trace magnetic power spectrum in the solar wind is known to be characterized by a double power law at scales much larger than the proton gyro-radius, with flatter spectral exponents close to −1 found at the lower frequencies below an inertial range with indices closer to [−1.5, −1.67]. The origin of the 1/ f range is still under debate. In this study, we selected 109 magnetically incompressible solar wind intervals ( δ ∣ B ∣/∣ B ∣ ≪ 1) from Parker Solar Probe encounters 1–13 that display such double power laws, with the aim of understanding the statistics and radial evolution of the low-frequency power spectral exponents from Alfvén point up to 0.3 au. New observations from closer to the Sun show that in the low-frequency range solar wind, turbulence can display spectra much shallower than 1/ f , evolving asymptotically to 1/ f as advection time increases, indicating a dynamic origin for the 1/ f range formation. We discuss the implications of this result on the Matteini et al. conjecture for the 1/ f origin as well as example spectra displaying a triple power law consistent with the model proposed by Chandran et al., supporting the dynamic role of parametric decay in the young solar wind. Our results provide new constraints on the origin of the 1/ f spectrum and further show the possibility of the coexistence of multiple formation mechanisms.
Keywords
