Mesogranulation and the solar surface magnetic field distribution

Abstract

The relation of the solar surface magnetic field with mesogranular cells is studied using high spatial (~ 100 km) and temporal (~ 30 sec) resolution data obtained with the IMaX instrument aboard SUNRISE. First, mesogranular cells are identified using Lagrange tracers (corks) based on horizontal velocity fields obtained through Local Correlation Tracking. After ~ 20 min of integration, the tracers delineate a sharp mesogranular network with lanes of width below about 280 km. The preferential location of magnetic elements in mesogranular cells is tested quantitatively. Roughly 85% of pixels with magnetic field higher than 100 G are located in the near neighborhood of mesogranular lanes. Magnetic flux is therefore concentrated in mesogranular lanes rather than intergranular ones. Secondly, magnetic field extrapolations are performed to obtain field lines anchored in the observed flux elements. This analysis, therefore, is independent of the horizontal flows determined in the first part. A probability density function (PDF) is calculated for the distribution of distances between the footpoints of individual magnetic field lines. The PDF has an exponential shape at scales between 1 and 10 Mm, with a constant characteristic decay distance, indicating the absence of preferred convection scales in the mesogranular range. Our results support the view that mesogranulation is not an intrinsic convective scale (in the sense that it is not a primary energy-injection scale of solar convection), but also give quantitative confirmation that, nevertheless, the magnetic elements are preferentially found along mesogranular lanes.

Accepted for publication in ApJ Letters, 16 pages, 5 figures

References in corpus (8)

• Optimization code with weighting function for the reconstruction of coronal magnetic fields
• Sunrise: instrument, mission, data and first results
• The Imaging Magnetograph eXperiment (IMaX) for the Sunrise balloon-borne solar observatory
• Quiet Sun internetwork magnetic fields from the inversion of Hinode measurements
• DOT tomography of the solar atmosphere. IV. Magnetic patches in internetwork areas
• Magnetic loops in the quiet Sun
• Spatial and temporal distributions of transient horizontal magnetic fields with deep exposure
• Mesoscale dynamics on the Sun's surface from HINODE observations

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