Phase coherence of solar wind turbulence from the Sun to Earth
The transport of energetic particles in response to solar wind turbulence is important for space weather. To understand charged particle transport, it is usually assumed that the phase of the turbulence is randomly distributed (the random phase approximation) in quasi-linear theory and simulations....
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Frontiers Media S.A.
2023-04-01
|
| Series: | Frontiers in Astronomy and Space Sciences |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/articles/10.3389/fspas.2023.1161939/full |
| _version_ | 1827964197064933376 |
|---|---|
| author | Masaru Nakanotani Lingling Zhao Gary P. Zank |
| author_facet | Masaru Nakanotani Lingling Zhao Gary P. Zank |
| author_sort | Masaru Nakanotani |
| collection | DOAJ |
| description | The transport of energetic particles in response to solar wind turbulence is important for space weather. To understand charged particle transport, it is usually assumed that the phase of the turbulence is randomly distributed (the random phase approximation) in quasi-linear theory and simulations. In this paper, we calculate the coherence index, Cϕ, of solar wind turbulence observed by the Helios 2 and Parker Solar Probe spacecraft using the surrogate data technique to check if the assumption is valid. Here, values of Cϕ = 0 and 1 indicate that the phase coherence is random and correlated, respectively. We estimate that the coherence index at the resonant scale of energetic ions (10 MeV protons) is 0.1 at 0.87 and 0.65 au, 0.18 at 0.29 au, and 0.3 (0.35) at 0.09 au for super (sub)-Alfvénic intervals, respectively. Since the random phase approximation corresponds to Cϕ = 0, this may indicate that the random phase approximation is not valid for the transport of energetic particles in the inner heliosphere, especially very close to the Sun (∼0.09 au). |
| first_indexed | 2024-04-09T17:11:55Z |
| format | Article |
| id | doaj.art-ce67cbbcf09c4fbc883d56bc03ad74ea |
| institution | Directory Open Access Journal |
| issn | 2296-987X |
| language | English |
| last_indexed | 2024-04-09T17:11:55Z |
| publishDate | 2023-04-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Astronomy and Space Sciences |
| spelling | doaj.art-ce67cbbcf09c4fbc883d56bc03ad74ea2023-04-20T05:56:27ZengFrontiers Media S.A.Frontiers in Astronomy and Space Sciences2296-987X2023-04-011010.3389/fspas.2023.11619391161939Phase coherence of solar wind turbulence from the Sun to EarthMasaru NakanotaniLingling ZhaoGary P. ZankThe transport of energetic particles in response to solar wind turbulence is important for space weather. To understand charged particle transport, it is usually assumed that the phase of the turbulence is randomly distributed (the random phase approximation) in quasi-linear theory and simulations. In this paper, we calculate the coherence index, Cϕ, of solar wind turbulence observed by the Helios 2 and Parker Solar Probe spacecraft using the surrogate data technique to check if the assumption is valid. Here, values of Cϕ = 0 and 1 indicate that the phase coherence is random and correlated, respectively. We estimate that the coherence index at the resonant scale of energetic ions (10 MeV protons) is 0.1 at 0.87 and 0.65 au, 0.18 at 0.29 au, and 0.3 (0.35) at 0.09 au for super (sub)-Alfvénic intervals, respectively. Since the random phase approximation corresponds to Cϕ = 0, this may indicate that the random phase approximation is not valid for the transport of energetic particles in the inner heliosphere, especially very close to the Sun (∼0.09 au).https://www.frontiersin.org/articles/10.3389/fspas.2023.1161939/fullphase coherencesolar wind turbulenceinner heliospheresurrogate data techniqueparticle transport |
| spellingShingle | Masaru Nakanotani Lingling Zhao Gary P. Zank Phase coherence of solar wind turbulence from the Sun to Earth Frontiers in Astronomy and Space Sciences phase coherence solar wind turbulence inner heliosphere surrogate data technique particle transport |
| title | Phase coherence of solar wind turbulence from the Sun to Earth |
| title_full | Phase coherence of solar wind turbulence from the Sun to Earth |
| title_fullStr | Phase coherence of solar wind turbulence from the Sun to Earth |
| title_full_unstemmed | Phase coherence of solar wind turbulence from the Sun to Earth |
| title_short | Phase coherence of solar wind turbulence from the Sun to Earth |
| title_sort | phase coherence of solar wind turbulence from the sun to earth |
| topic | phase coherence solar wind turbulence inner heliosphere surrogate data technique particle transport |
| url | https://www.frontiersin.org/articles/10.3389/fspas.2023.1161939/full |
| work_keys_str_mv | AT masarunakanotani phasecoherenceofsolarwindturbulencefromthesuntoearth AT linglingzhao phasecoherenceofsolarwindturbulencefromthesuntoearth AT garypzank phasecoherenceofsolarwindturbulencefromthesuntoearth |