CHROMOSPHERIC EVOLUTION AND THE FLARE ACTIVITY OF SUPER-ACTIVE REGIONNOAA-6555

Super-active region NOAA 6555 was highly flare productive during the p eriod March 21st - 27th, 1991 of its disk passage. We have studied its chromospheric activity using high spatial resolution H alpha filtergr ams taken at Udaipur along with MSFC vector magnetograms. A possible r elationship of flare productivity and the variation in shear has been explored. mares were generally seen in those subareas of the active re gion which possessed closed magnetic field configuration, whereas only minor flares and/or surges occurred in subareas showing open magnetic field configuration. Physical mechanisms responsible for the observed surges are also discussed.