Appraisal of solar activity at Pakistan atmospheric regions

This study presents an indigenous work to investigate periodicity in solar flare duration (sfd) at pakistan atmospherics region over a period of 1979-2006. the disorderly behavior of solar flare generates solar protons which often associated with gradual flares and coronal mass ejection (cme). their adverse effects are on space weather and hence orbiting satellites and radio wave communication system. therefore a better understanding of periodic activities in the sun is useful for the prediction of the effects of solar activity on earth. we revealed the first peak periodicity in the mixed series of solar flare duration (sfd) and implemented a test of periodic ordinate and confidence interval to substantiate the results. gradual flares are undesirable to the terrestrial climate so we separate the series of impulsive and gradual flares from the mixed series and revealed their periodic behavior as well. this study intended to propose that periodic behavior in the solar flare duration may be one of the important aspects of solar flare activity. © pakistan academy of sciences.