Diffusion of solar magnetic elements up to supergranular spatial and temporal scales

TL;DR

This study analyzes the diffusion behavior of small magnetic elements on the quiet Sun's photosphere across granular and supergranular scales using high-resolution Hinode magnetograms, revealing a double-regime superdiffusive process.

Contribution

It provides the first large-scale, high-resolution measurement of magnetic element diffusion over supergranular scales, highlighting a double-regime superdiffusive process.

Findings

Magnetic elements exhibit superdiffusive behavior up to supergranular scales.

The diffusion exponent is approximately 1.34 at granular scales.

The diffusion exponent decreases slightly to about 1.20 at supergranular scales.

Abstract

The study of spatial and temporal scales on which small magnetic structures (magnetic elements) are organized in the quiet Sun may be approached by determining how they are transported on the solar photosphere by convective motions. The process involved is diffusion. Taking advantage of Hinode high spatial resolution magnetograms of a quiet Sun region at the disk center, we tracked 20145 magnetic elements. The large field of view (~50 Mm) and the long duration of the observations (over 25 hours without interruption at a cadence of 90 seconds) allowed us to investigate the turbulent flows at unprecedented large spatial and temporal scales. In the field of view, in fact, an entire supergranule is clearly recognizable. The magnetic elements displacement spectrum shows a double-regime behavior: superdiffusive (gamma=1.34 +/- 0.02) up to granular spatial scales (~1500 km), and slightly superdiffusive (gamma=1.20 +/- 0.05) up to supergranular scales.