Letter to the Editor

Evidence of mesogranulation from magnetograms of the Sun

Universitäts-Sternwarte, Geismarlandstraße 11, 37083 Göttingen, Germany

Corresponding author: ita@uni-sw.gwdg.de

Received: 29 October 2003
Accepted: 14 November 2003

Abstract

This work confirms the existence of the mesogranulation as an intermediate scale of convection in the solar photosphere. The main argument presented is the correlation between horizontal flows obtained with two different methods (Local Correlation Tracking, and gradient of granular intensities), and the pattern observed in magnetograms above a fixed threshold of the magnetic signal. The data used consist of a time series (40 min) of high spatial resolution images of intensity and simultaneous magnetograms. The size of the scales found is 5´´–10´´ (3.6-7.2 Mm), but some mesogranules close to supergranular boundaries can be smaller, and appear to be stabilized by the network magnetic fields.