Filament activity and photospheric magnetic evolution related to flares

Three succcssive activations of all active-region filament were observed over a period of eight hours. Each disturbance showed distinctive characteristics and was followed by a flare of different properties. The filament had one end rooted in strong delta -sunspots. During the first activation, the filament rose up at the rooting end and detached from the delta -sunspots while its main body remained in place and separated into two twisted threads. During the second activation, only one thread a as disturbed and finally disappeared; twisted threads, however, appeared during the third activation. The evolution of photospheric magnetic fields, associated with the filament disturbances. Was characterized by squeezing and shearing of delta -sunspots, flux cancellation and emergence beneath the two ends of the filaments. Our data suggests that magnetic reconnection in the photospheric layer is the likely cause of filament destabilisation. cause of filament destabilisation.