MESOGRANULATION AND THE SOLAR SURFACE MAGNETIC FIELD DISTRIBUTION
- Instituto de Astrofisica de Canarias, Via Lactea, s/n, 38205 La Laguna (Tenerife) (Spain)
- Max-Planck-Institut fuer Sonnensystemforschung, Max-Planck-Strasse 2, 37191 Katlenburg-Lindau (Germany)
- High Altitude Observatory (NCAR), Boulder, CO 80307 (United States)
- Instituto de Astrofisica de Andalucia (CSIC), Glorieta de la Astronomia, s/n 18008 Granada (Spain)
- Kiepenheuer-Institut fuer Sonnenphysik, 79104 Freiburg (Germany)
The relation of the solar surface magnetic field with mesogranular cells is studied using high spatial ({approx}100 km) and temporal ({approx}30 s) resolution data obtained with the IMaX instrument on board SUNRISE. First, mesogranular cells are identified using Lagrange tracers (corks) based on horizontal velocity fields obtained through local correlation tracking. After {approx}20 minutes 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. Second, 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.
- OSTI ID:
- 21560547
- Journal Information:
- Astrophysical Journal Letters, Vol. 727, Issue 2; Other Information: DOI: 10.1088/2041-8205/727/2/L30; ISSN 2041-8205
- Country of Publication:
- United States
- Language:
- English
Similar Records
Simulation of large-scale flows at the solar surface
Simulation of large-scale flows at the solar surface