DOT tomography of the solar atmosphere. IV. Magnetic patches in internetwork areas

TL;DR

This study uses high-resolution solar images to analyze magnetic patches in internetwork areas, revealing their long lifetimes and organization on mesogranular scales, challenging the local turbulent dynamo hypothesis.

Contribution

Developed an algorithm to detect magnetic patches and demonstrated their long lifetimes and organization, providing new insights into solar magnetic flux behavior.

Findings

Magnetic patches last approximately 9 hours.

Patches outline mesogranular cell patterns.

Magnetic elements are not generated by local turbulent dynamo.

Abstract

We use G-band and Ca II H image sequences from the Dutch Open Telescope (DOT) to study magnetic elements that appear as bright points in internetwork parts of the quiet solar photosphere and chromosphere. We find that many of these bright points appear recurrently with varying intensity and horizontal motion within longer-lived magnetic patches. We develop an algorithm for detection of the patches and find that all patches identified last much longer than the granulation. The patches outline cell patterns on mesogranular scales, indicating that magnetic flux tubes are advected by granular flows to mesogranular boundaries. Statistical analysis of the emergence and disappearance of the patches points to an average patch lifetime as long as 530+-50 min (about nine hours), which suggests that the magnetic elements constituting strong internetwork fields are not generated by a local turbulent dynamo.