Automation of Tracking Various Sunspot Group Entities and Demonstrating Its Usage on the Flaring NOAA AR 11429
| Autor: | L. Győri |
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| Rok vydání: | 2015 |
| Předmět: | |
| Zdroj: | Solar Physics. 290:1627-1645 |
| ISSN: | 1573-093X 0038-0938 |
| DOI: | 10.1007/s11207-015-0714-z |
| Popis: | A method based on set and graph operations was developed to find and track related entities of sunspot groups on a series of consecutive solar images. Of course, if we can track entities of a sunspot group, we can also track various properties (e.g., position, area, magnetic field, and intensity) associated with them. A new higher-level sunspot-group entity belonging to the whole image series, a family, was introduced to cope with the mergings and separations of various sunspot group entities. To demonstrate the usefulness of the method, it was applied to NOAA AR 11429 using Solar Dynamics Observatory/Helioseismic and Magnetic Imager (SDO/HMI) images. This large sunspot group produced several X, M, and C class flares, among others, an X5.4 class flare on 2012 March 7. Abrupt transient and permanent variations in the mean line-of-sight (LOS) magnetic field of the large umbra families were found during the X5.4 flare. Two small umbra families immediately next to the polarity inversion line (PIL) and facing each other at opposite sides of the PIL exhibited abrupt stepwise changes in their mean LOS magnetic field during the X5.4 flare. The family with positive polarity decreased and the family with negative polarity increased. Some of the large umbra families also showed abrupt decrease in their darkness during the flare. We conjecture that an umbra family being a part of a long, narrow magnetic field strip pushing in an opposite magnetic polarity penumbral domain might be one of the triggering causes of several flares. Flare-related changes were observed at every spatial scale of the studied sunspot group. Two of the large opposite-polarity umbra families underwent shearing and converging motions. The break and the turning points of the motion curves of these families were related to flares. Some of the flares coincided with abrupt changes in the motion curves. |
| Databáze: | OpenAIRE |
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