Solar Wind Turbulence and Complexity Probed with Rank-Ordered Multifractal Analysis (ROMA)

Area of Science:

• Space Physics
• Plasma Physics
• Astrophysics

Background:

• Solar wind turbulence is a complex phenomenon crucial for understanding energy transfer in space.
• Characterizing multifractality and scale-invariance in turbulent plasmas is essential for astrophysical studies.

Purpose of the Study:

• To apply Rank-Ordered Multifractal Analysis (ROMA) to characterize solar wind turbulence.
• To compare the multifractal properties of fast and slow solar wind using spacecraft data.

Main Methods:

• Rank-Ordered Multifractal Analysis (ROMA) was employed to analyze fluctuations.
• Range-limited structure-function analysis was used to determine mono-fractal indices.
• Data from Ulysses (fast solar wind) and Venus Express (slow solar wind) spacecraft were analyzed.

Main Results:

• Fast solar wind exhibits scale-dependent fluctuations: persistent at kinetic scales and anti-persistent at inertial scales.
• Slow solar wind shows fully developed multifractal turbulence with a transition in Hurst index.
• Small-scale fluctuations in slow solar wind tend towards mono-fractal behavior.

Conclusions:

• ROMA effectively differentiates multifractal characteristics of fast and slow solar wind turbulence.
• The findings provide insights into the scale-dependent nature and complexity of solar wind dynamics.
• Differentiation of turbulence structures has implications for understanding plasma behavior in heliospheric environments.