Solar Magnetic Tracking. I. Software Comparison and Recommended Practices

Feature tracking and recognition are increasingly common tools for data analysis, but are typically implemented on an ad hoc basis by individual research groups, limiting the usefulness of derived results when selection effects and algorithmic differences are not controlled. Specific results that are affected include the solar magnetic turnover time, the distributions of sizes, strengths, and lifetimes of magnetic features, and the physics of both small scale flux emergence and the small-scale dynamo. In this paper, we present the results of a detailed comparison between four tracking codes applied to a single set of data from SOHO/MDI, describe the interplay between desired tracking behavior and parameterization tracking algorithms, and make recommendations for feature selection and tracking practice in future work.

[1]  C. Schrijver,et al.  Sustaining the Quiet Photospheric Network: The Balance of Flux Emergence, Fragmentation, Merging, and Cancellation , 1997 .

[2]  C. Schrijver,et al.  The Properties of Small Magnetic Regions on the Solar Surface and the Implications for the Solar Dynamo(s) , 2002 .

[3]  P. Jupp,et al.  Statistical Analysis of the Energy Distribution of Nanoflares in the Quiet Sun , 2000 .

[4]  J. Leibacher.  The Global Oscillation Network Group Project , 1996 .

[5]  C. Schrijver,et al.  Dispersal of Magnetic Flux in the Quiet Solar Photosphere , 1999 .

[6]  D. A. Lamb,et al.  Clustering of the Small-Scale Field , 2004 .

[7]  C. J. Wolfson,et al.  The Solar Oscillations Investigation - Michelson Doppler Imager , 1995 .

[8]  Sara F. Martin,et al.  Ephemeral active regions , 1973 .

[9]  Alan M. Title,et al.  PHENOMENA IN AN EMERGING ACTIVE REGION. I. HORIZONTAL DYNAMICS , 1996 .

[10]  José Carlos Goulart de Siqueira,et al.  Differential Equations , 1919, Nature.

[11]  N. Weiss,et al.  Sustaining the Sun’s Magnetic Network with Emerging Bipoles , 2001 .

[12]  E. Parker.  Nanoflares and the solar X-ray corona , 1988 .

[13]  Haimin Wang,et al.  Small Magnetic Bipoles Emerging in a Filament Channel , 2001 .

[14]  Clare E. Parnell,et al.  Nature of the magnetic carpet – I. Distribution of magnetic fluxes , 2002 .

[15]  Brad Thompson,et al.  The SDO Mission , 2002 .

[16]  S. Regnier,et al.  ILCT: Recovering Photospheric Velocities from Magnetograms by Combining the Induction Equation with Local Correlation Tracking , 2004 .

[17]  Jay A. Bookbinder,et al.  The transition region and coronal explorer , 1998 .

[18]  Craig E. Deforest,et al.  On Re-sampling of Solar Images , 2004 .

[19]  B. Welsch,et al.  Magnetic Helicity Injection by Horizontal Flows in the Quiet Sun. I. Mutual-Helicity Flux , 2003 .

[20]  H. Snodgrass.  Magnetic rotation of the solar photosphere , 1983 .

[21]  Craig E. Deforest,et al.  High-Frequency Waves Detected in the Solar Atmosphere , 2004 .