Study of Magnetic Complexity of Solar Active Regions from 1996 to 2017
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Date
2018
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en
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Solar Active Regions (ARs) are areas on the photosphere where the sun'smagnetic field is especially strong. Major manifestations of the solar magnetic activity, such as flares and Coronal Mass Ejections (CMEs), are associated with ARs. The Mount Wilson Classification groups ARsaccording to their magnetic structures from the less complex, Alphaclass, to the more complex one, Beta-Gamma-Delta class. In this study,we investigated the Mount Wilson magnetic classification and latitudedata of 4760 ARs from January 1996 to December 2017. We showed that theabundance of Simple ARs (SARs) follows very closely the sunspot number.In addition, we found that in both cycle 23 and 24, the abundance ofSARs peaks during the sunspot maximum. On the other hand, the abundanceof Complex ARs (CARs) reaches its maximum value two years after solarmaximum in both cycles. We also studied the latitudinal distributionsof the different magnetic complexity classes, and found out that,independent of the complexity type, the northern andsoutherndistributions are the same. Furthermore, we investigated the earlierclaim of the time lag in between SARs and CARs being due to thebutterfly wing widths getting narrower as the cycle progresses, forcingthe rising flux tubes to get more packed and the resulting activeregions more complex. The maximum of CARs, however, was clearly seen tooccur before the linear decrease of the wing widths took place, makingthis scenario unlikely.Description
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Nikbakhsh , S , Tanskanen , E , Hackman , T & Käpylä , M 2018 , ' Study of Magnetic Complexity of Solar Active Regions from 1996 to 2017 ' , European Geosciences Union General Assembly , Vienna , Austria , 08/04/2018 - 13/04/2018 . < https://meetingorganizer.copernicus.org/EGU2018/EGU2018-16625.pdf >
