Mesogranular structure in a hydrodynamical simulation

¹ Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Strasse 2, 37191 Katlenburg-Lindau, Germany e-mail: matloch@mps.mpg.de
² Astrophysics Research Center, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland, UK

Received: 22 March 2010
Accepted: 23 June 2010

Abstract

Aims. We analyse mesogranular flow patterns in a three-dimensional hydrodynamical simulation of solar surface convection in order to determine its characteristics.

Methods. We calculate divergence maps from horizontal velocities obtained with the local correlation tracking (LCT) method. Mesogranules are identified as patches of positive velocity divergence. We track the mesogranules to obtain their size and lifetime distributions. We vary the analysis parameters to verify if the pattern has characteristic scales.

Results. The characteristics of the resulting flow patterns depend on the averaging time and length used in the analysis.

Conclusions. We conclude that the mesogranular patterns do not exhibit intrinsic length and time scales.