Abstract
An application of active contours without edges is presented as an efficient and effective means of extracting and characterizing coronal holes. Coronal holes are regions of low-density plasma on the Sun with open magnetic field lines. The detection and characterization of these regions is important for testing theories of their formation and evolution, and also from a space weather perspective because they are the source of the fast solar wind. Coronal holes are detected in full-disk extreme ultraviolet (EUV) images of the corona obtained with the Solar Dynamics Observatory Atmospheric Imaging Assembly (SDO/AIA). The proposed method detects coronal boundaries without determining any fixed intensity value in the data. Instead, the active contour segmentation employs an energy-minimization in which coronal holes are assumed to have more homogeneous intensities than the surrounding active regions and quiet Sun. The segmented coronal holes tend to correspond to unipolar magnetic regions, are consistent with concurrent solar wind observations, and qualitatively match the coronal holes segmented by other methods. The means to identify a coronal hole without specifying a final intensity threshold may allow this algorithm to be more robust across multiple datasets, regardless of data type, resolution, and quality.
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Altschuler, M.D., Trotter, D.E., Orrall, F.Q.: 1972, Coronal holes. Solar Phys. 26(2), 354. DOI .
Antonucci, E., Dodero, M.A., Giordano, S., Krishnakumar, V., Noci, G.: 2004, Spectroscopic measurement of the plasma electron density and outflow velocity in a polar coronal hole. Astron. Astrophys. 416(2), 749. DOI .
Caplan, R.M., Downs, C., Linker, J.A.: 2016, Synchronic coronal hole mapping using multi-instrument EUV images: Data preparation and detection method. Astrophys. J. 823, 53. DOI .
Chan, T.F., Vese, L.A.: 2001, Active contours without edges. IEEE Trans. Image Process. 10(2), 266. DOI .
Chiu, M.C., Von-Mehlem, U.I., Willey, C.E., Betenbaugh, T.M., Maynard, J.J., Krein, J.A., Conde, R.F., Gray, W.T., Hunt, J.W. Jr., Mosher, L.E., McCullough, M.G., Panneton, P.E., Staiger, J.P., Rodberg, E.H.: 1998, ACE spacecraft. Space Sci. Rev. 86(1), 257. DOI .
Colak, T., Qahwaji, R.: 2013, Prediction of Extreme Ultraviolet Variability Experiment (EVE)/Extreme Ultraviolet Spectro-Photometer (ESP) irradiance from Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) images using fuzzy image processing and machine learning. Solar Phys. 283(1), 143. DOI .
de Toma, G.: 2011, Evolution of coronal holes and implications for high-speed solar wind during the minimum between cycles 23 and 24. Solar Phys. 274(1 – 2), 195. DOI .
DeForest, C.E., Hagenaar, H.J., Lamb, D.A., Parnell, C.E., Welsch, B.T.: 2007, Solar magnetic tracking. I. Software comparison and recommended practices. Astrophys. J. 666(1), 576. DOI .
Dudok de Wit, T.: 2006, Fast segmentation of solar extreme ultraviolet images. Solar Phys. 239(1 – 2), 519. DOI .
Gopalswamy, N., Mäkelä, P., Xie, H., Akiyama, S., Yashiro, S.: 2009, CME interactions with coronal holes and their interplanetary consequences. J. Geophys. Res. 114(A3), A00A22. DOI .
Harvey, K.L., Recely, F.: 2002, Polar coronal holes during cycles 22 and 23. Solar Phys. 211(1 – 2), 31. DOI .
Hassler, D.M., Dammasch, I.E., Lemaire, P., Brekke, P., Curdt, W., Mason, H.E., Vial, J.-C., Wilhelm, K.: 1999, Solar wind outflow and the chromospheric magnetic network. Science 283(5403), 810. DOI .
Henney, C.J., Harvey, J.W.: 2005, Automated coronal hole detection using He I 1083 nm spectroheliograms and photospheric magnetograms. In: Large-Scale Structures and Their Role in Solar Activity, ASP Conf. Series 346, 261.
Kass, M., Witkin, A., Terzopoulos, D.: 1988, Snakes: Active contour models. Int. J. Comput. Vis. 1(4), 321. DOI .
Kirk, M.S., Pesnell, W.D., Young, C.A., Hess Webber, S.A.: 2009, Automated detection of EUV polar coronal holes during solar cycle 23. Solar Phys. 257(1), 99. DOI .
Krieger, A.S., Timothy, A.F., Roelof, E.C.: 1973, A coronal hole and its identification as the source of a high velocity solar wind stream. Solar Phys. 29(2), 505. DOI .
Krista, L.D., Gallagher, P.T.: 2009, Automated coronal hole detection using local intensity thresholding techniques. Solar Phys. 256(1 – 2), 87. DOI .
Lemen, J.R., Title, A.M., Akin, D.J., Boerner, P.E., Chou, C., Drake, J.F., Duncan, D.W., Edwards, C.G., Fridlaender, F.M., Heyman, G.F., Hurlburt, N.E., Katz, N.L., Kushner, G.D., Levay, M., Lindgren, R.W., Mathur, D.P., McFeaters, E.L., Mitchell, S., Rehse, R.A., Schrijver, C.J., Wolfram, C.J., Yanari, C., Bookbinder, J.A., Cheimets, P.N., Caldwell, D., Deluca, E.E., Gates, R., Golub, L., Park, S., Podgorski, W.A., Bush, R.I., Scherrer, P.H., Gummin, M.A., Smith, P., Auker, G., Jerram, P., Pool, P., Soufli, R., Windt, D.L., Beardsley, S., Clapp, M., Lang, J., Waltham, N.: 2012, The Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO). Solar Phys. 275, 17. DOI .
Lowder, C., Qiu, J., Leamon, R., Liu, Y.: 2014, Measurements of EUV coronal holes and open magnetic flux. Astrophys. J. 783, 142. DOI .
Malanushenko, O.V., Jones, H.P.: 2005, Differentiating coronal holes from the quiet Sun by He 1083 nm imaging spectroscopy. Solar Phys. 226(1), 3. DOI .
Martens, P.C.H., Atrrill, G.D.R., Davey, A.R., Engell, A., Farid, S., Grigis, P.C., Kasper, J., Korreck, K., Saar, S.H., Savcheva, A., Su, Y., Testa, P., Wills-Davey, M., Bernasconi, P.N., Raouafi, N.-E., Delouille, V.A., Hochedez, J.F., Cirtain, J.W., DeForest, C.E., Angryk, R.A., De Moortel, I., Wiegelmann, T., Georgoulis, M.K., McAteer, R.T.J., Timmons, R.P.: 2011, Computer vision for the Solar Dynamics Observatory (SDO). Solar Phys. 275(1 – 2), 79. DOI .
Mumford, D., Shah, J.: 1989, Optimal approximation by piecewise smooth functions and associated variational problems. Commun. Pure Appl. Math. 42(5), 577. DOI .
Robbins, S., Henney, C.J., Harvey, J.W.: 2006, Solar wind forecasting with coronal holes. Solar Phys. 233(2), 265. DOI .
Rotter, T., Veronig, A.M., Temmer, M., Vršnak, B.: 2015, Real-time solar wind prediction based on SDO/AIA coronal hole data. Solar Phys. 290(5), 1355. DOI .
Scherrer, P.H., Schou, J., Bush, R.I., Kosovichev, A.G., Bogart, R.S., Hoeksema, J.T., Liu, Y., Duvall, T.L. Jr., Zhao, J., Title, A.M., Schrijver, C.J., Tarbell, T.D., Tomczyk, S.: 2012, The Helioseismic and Magnetic Imager (HMI) investigation for the Solar Dynamics Observatory (SDO). Solar Phys. 275, 207. DOI .
Scholl, I.F., Habbal, S.R.: 2008, Automatic detection and classification of coronal holes and filaments based on EUV and magnetogram observations of the solar disk. Solar Phys. 248(2), 425. DOI .
Schwadron, N.A., McComas, D.J.: 2003, Solar wind scaling law. Astrophys. J. 599(2), 1395. DOI .
Verbeeck, C., Delouille, V., Mampaey, B., De Visscher, R.: 2014, The SPoCA-suite: Software for extraction, characterization, and tracking of active regions and coronal holes on EUV images. Astron. Astrophys. 561, A64. DOI .
Vršnak, B., Temmer, M., Veronig, A.M.: 2007, Coronal holes and solar wind high-speed streams: I. Forecasting the solar wind parameters. Solar Phys. 240(2), 315. DOI .
Wang, Y.-M., Hawley, S.H., Sheeley, N.R. Jr.: 1996, The magnetic nature of coronal holes. Science 271(5248), 464. DOI .
Acknowledgements
The authors gratefully acknowledge NASA PAARE grant AST-0849986, NASA EPSCoR grant NNX09AP76A, and NSF CAREER grant 1255024, which helped support this work. The authors also thank Michael Kirk for productive discussions regarding this work and comments on the manuscript. SDO images used in this work are courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.
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Boucheron, L.E., Valluri, M. & McAteer, R.T.J. Segmentation of Coronal Holes Using Active Contours Without Edges. Sol Phys 291, 2353–2372 (2016). https://doi.org/10.1007/s11207-016-0985-z
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DOI: https://doi.org/10.1007/s11207-016-0985-z