Eintrag weiter verarbeiten
Ion‐scale spectral break of solar wind turbulence at high and low beta
Gespeichert in:
| Zeitschriftentitel: | Geophysical Research Letters |
|---|---|
| Personen und Körperschaften: | , , , , |
| In: | Geophysical Research Letters, 41, 2014, 22, S. 8081-8088 |
| Format: | E-Article |
| Sprache: | Englisch |
| veröffentlicht: |
American Geophysical Union (AGU)
|
| Schlagwörter: |
| Zusammenfassung: | <jats:title>Abstract</jats:title><jats:p>The power spectrum of magnetic fluctuations in the solar wind at 1 AU displays a break between two power laws in the range of spacecraft‐frame frequencies 0.1 to 1 Hz. These frequencies correspond to spatial scales in the plasma frame near the proton gyroradius <jats:italic>ρ</jats:italic><jats:sub>i</jats:sub> and proton inertial length <jats:italic>d</jats:italic><jats:sub>i</jats:sub>. At 1 AU it is difficult to determine which of these is associated with the break, since <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="graphic/grl52226-math-0001.png" xlink:title="urn:x-wiley:grl:media:grl52226:grl52226-math-0001" /> and the perpendicular ion plasma beta is typically <jats:italic>β</jats:italic><jats:sub>⊥i</jats:sub>∼1. To address this, several exceptional intervals with <jats:italic>β</jats:italic><jats:sub>⊥i</jats:sub>≪1 and <jats:italic>β</jats:italic><jats:sub>⊥i</jats:sub>≫1 were investigated, during which these scales were well separated. It was found that for <jats:italic>β</jats:italic><jats:sub>⊥i</jats:sub>≪1 the break occurs at <jats:italic>d</jats:italic><jats:sub>i</jats:sub> and for <jats:italic>β</jats:italic><jats:sub>⊥i</jats:sub>≫1 at <jats:italic>ρ</jats:italic><jats:sub>i</jats:sub>, i.e., the larger of the two scales. Possible explanations for these results are discussed, including Alfvén wave dispersion, damping, and current sheets.</jats:p> |
|---|---|
| Umfang: | 8081-8088 |
| ISSN: |
0094-8276
1944-8007 |
| DOI: | 10.1002/2014gl062009 |