Statistical Analysis of Field-Aligned Alfvénic Turbulence and Intermittency in Fast Solar Wind

• Main Authors: Francesco Carbone, Daniele Telloni, Luca Sorriso-Valvo, Gary Zank, Lingling Zhao, Laxman Adhikari, Roberto Bruno
• Format: Article
• Language: English
• Published: MDPI AG 2020-08-01
• Series: Universe
• Subjects: solar wind; turbulence; scaling laws
• Online Access: https://www.mdpi.com/2218-1997/6/8/116

The statistical properties of fast Alfvénic solar wind turbulence have been analyzed by means of empirical mode decomposition and the associated Hilbert spectral analysis. The stringent criteria employed for the data selection in the Wind spacecraft database, has made possible to sample multiple <inline-formula><math display="inline"><semantics><msub><mi>k</mi><mo>‖</mo></msub></semantics></math></inline-formula> field-aligned intervals of the three magnetic field components. The results suggest that the spectral anisotropy predicted by the critical balance theory is not observed in the selected database, whereas a Kolmogorov-like scaling (<inline-formula><math display="inline"><semantics><mrow><mi>E</mi><mrow><mo>(</mo><msub><mi>k</mi><mo>‖</mo></msub><mo>)</mo></mrow><mo>∼</mo><msup><mi>k</mi><mrow><mo>−</mo><mn>5</mn><mo>/</mo><mn>3</mn></mrow></msup></mrow></semantics></math></inline-formula>) and a weak or absent level of intermittency are robust characteristics of the Alfvénic slab component of solar wind turbulence.