Statistical Analysis of Photospheric Vertical Current Structure in Flaring Active Regions

Abstract:

We present statistical analysis of the spatial structure of the vertical current in 40 active regions associated with flares of GOES C9.0 class and greater. For every event in the database, we use 1) a sequence of HMI/SDO vector magnetograms, to track magnetic field properties before and after the flare and 2) a sequence of AIA/SDO 1600A images, to track location of flare ribbons. We calculate the following physical properties of the photospheric vector magnetic field before and after the flare within the active region, areas swept by the flare ribbon and the polarity inversion line: magnetic shear, vertical electric current, current neutralization and free energy proxy. We present the results and discuss their meaning in the context of the standard flare model.