# Multifractal Analysis of Heliospheric Magnetic Field Fluctuations observed by Ulysses

## TL;DR

This study uses multifractal analysis to examine magnetic field turbulence in the solar wind observed by Ulysses, revealing how intermittency varies with distance, latitude, and solar cycle, and identifying differences between fast and slow solar wind.

## Contribution

It provides the first detailed multifractal characterization of solar wind magnetic turbulence beyond the ecliptic plane across different solar cycle phases.

## Key findings

- Intermittency decreases with radial distance, more significantly in fast solar wind.
- Intermittency is stronger near the Sun and varies with heliolatitude.
- Slow solar wind during solar maximum shows lower multifractality than fast wind.

## Abstract

We present the multifractal study of the intermittency of the magnetic field turbulence in the fast and slow solar wind beyond the ecliptic plane during two solar minima (1997-1998, 2007-2008) and solar maximum (1999-2001). More precisely, we consider 126 time intervals of Ulysses magnetic field measurements, obtain the multifractal spectra, and examine the degree of multifractality as the measure of intermittency in the MHD range of scales, for a wide range of heliocentric distances and heliolatitudes. The results show a slow decrease of intermittency with the radial distance, which is more significant for the fast than for the slow solar wind. Analysis of Alfvenic and compressive fuctuations confirms the decrease of intermittency with distance and latitude. This radial dependence of multifractality/intermittency may be explained by a slower evolution of turbulence beyond the ecliptic plane and by the reduced efficiency of intermittency drivers with the distance from the Sun. Additionally, our analysis shows that the greatest differences between magnetic field components are revealed close to the Sun, where intermittency is the strongest. Moreover, we observe that the slow solar wind from the maximum of the solar cycle 23 exhibits in general, a lower level of multifractality (intermittency) than fast solar wind, which can be related to the idea of a new type of Alfvenic slow solar wind.