Observed Fluctuation Enhancement and Departure from WKB Theory in Sub-Alfvénic Solar Wind
Fuente:
arXiv
Enregistré dans:
| Auteurs principaux: | , , , , , , , , , , , , , , |
|---|---|
| Format: | Preprint |
| Publié: |
2024
|
| Sujets: | |
| Accès en ligne: | |
| Tags: |
Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
|
| _version_ | 1866916495638921216 |
|---|---|
| author | Ruffolo, David Thepthong, Panisara Pongkitiwanichakul, Peera Roy, Sohom Pecora, Francesco Bandyopadhyay, Riddhi Chhiber, Rohit Usmanov, Arcadi V. Stevens, Michael Badman, Samuel Romeo, Orlando Wang, Jiaming Goodwill, Joshua Goldstein, Melvyn L. Matthaeus, William H. |
| author_facet | Ruffolo, David Thepthong, Panisara Pongkitiwanichakul, Peera Roy, Sohom Pecora, Francesco Bandyopadhyay, Riddhi Chhiber, Rohit Usmanov, Arcadi V. Stevens, Michael Badman, Samuel Romeo, Orlando Wang, Jiaming Goodwill, Joshua Goldstein, Melvyn L. Matthaeus, William H. |
| contents | Using Parker Solar Probe data from orbits 8 through 17, we examine fluctuation amplitudes throughout the critical region where the solar wind flow speed approaches and then exceeds the Alfvén wave speed, taking account of various exigencies of the plasma data. In contrast to WKB theory for non-interacting Alfvén waves streaming away from the Sun, the magnetic and kinetic fluctuation energies per unit volume are not monotonically decreasing. Instead, there is clear violation of conservation of standard WKB wave action, which is consistent with previous indications of strong in-situ fluctuation energy input in the solar wind near the Alfvén critical region. This points to strong violations of WKB theory due to nonlinearity (turbulence) and major energy input near the critical region, which we interpret as likely due to driving by large-scale coronal shear flows. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2409_02612 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Observed Fluctuation Enhancement and Departure from WKB Theory in Sub-Alfvénic Solar Wind Ruffolo, David Thepthong, Panisara Pongkitiwanichakul, Peera Roy, Sohom Pecora, Francesco Bandyopadhyay, Riddhi Chhiber, Rohit Usmanov, Arcadi V. Stevens, Michael Badman, Samuel Romeo, Orlando Wang, Jiaming Goodwill, Joshua Goldstein, Melvyn L. Matthaeus, William H. Solar and Stellar Astrophysics Plasma Physics Space Physics Using Parker Solar Probe data from orbits 8 through 17, we examine fluctuation amplitudes throughout the critical region where the solar wind flow speed approaches and then exceeds the Alfvén wave speed, taking account of various exigencies of the plasma data. In contrast to WKB theory for non-interacting Alfvén waves streaming away from the Sun, the magnetic and kinetic fluctuation energies per unit volume are not monotonically decreasing. Instead, there is clear violation of conservation of standard WKB wave action, which is consistent with previous indications of strong in-situ fluctuation energy input in the solar wind near the Alfvén critical region. This points to strong violations of WKB theory due to nonlinearity (turbulence) and major energy input near the critical region, which we interpret as likely due to driving by large-scale coronal shear flows. |
| title | Observed Fluctuation Enhancement and Departure from WKB Theory in Sub-Alfvénic Solar Wind |
| topic | Solar and Stellar Astrophysics Plasma Physics Space Physics |
| url | https://arxiv.org/abs/2409.02612 |