Magnetic flux emergence and solar activity in an active region cluster

MINERO GARFIAS A.; CRISTIANI, G.; MANDRINI, C.H.; LARA, A.

Buenos Aires

Conferencia; Eleventh Latin American Conference on Space Geophysics; 2018

Asociación Latinoamericana de Geofísica Espacial

We investigate the violent events that occurred in November 2010 in the cluster of two active regions (ARs), NOAA numbers 11121 and 11123, using instruments onboard the Solar Dynamics Observatory.  Starting on 10 November and within one day the total magnetic flux increased by 70 % with the emergence of new groups of bipoles in AR 11123, which was accompanied by strong photospheric motions. During the flux emergence phase only very minor flares, with no associated coronal mass ejections (CMEs), were observed. Once the magnetic flux reached its maximum and the displacement of photospheric flux concentrations slowed down, flaring became more frequent with several related CMEs. Though magnetic flux emergence has been in general associated to flare and/or CME occurrence, for this particular set of events this does not seem to be the case. We follow the magnetic flux evolution, identify all the flares and CMEs during 10 -- 11 November, and determine the locations along the photospheric inversion lines (PILs) of flare kernels and sites of CME initiation. We discuss the probable origin of the discrepancy between usually accepted assumptions concerning flux emergence and flare and CME occurrence and the evolution of activity in the analyzed active region cluster.