| Abstract * |
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The kinematics of Coronal Mass Ejections (CMEs) (especially in the lower corona) is not yet understood properly, besides, their width, tilt-angle, aspect ratio also varies rapidly in some cases, which apart from possessing rich physics, can pose a potential threat to space weather. Motivated by the fact that cycle to cycle variation of slow and fast CMEs seem to be width dependent, we try to connect the effect of the source regions on the width distribution of these slow and fast CMEs and on their actual 3D kinematical profiles. For this, we select CMEs from solar cycle 23 and 24 and identify their source regions on the solar disk. The CMEs are segregated on the basis of their speed (as fast and slow) and their associated source regions (Active Regions (ARs), Quiescent Prominences (QPs) and Active Prominences(APs)). We study the width distribution of fast and slow CMEs in cycle 23 and 24 and effect of their source region on ithe distribution. With their source regions identified, and with the help of the Graduated Cylindrical Shell (GCS) model, we study their 3-D evolution in the lower and upper corona by stereoscopic observations with the combined data from COR-1 and COR-2 onboard STEREO A & B. We try to understand what effect do the different source regions (and hence their differing magnetic energy content and topology) have on the kinematics of slow and fast CMEs. A change in the tilt-angle (implying rotation of the flux-rope) and width (implying expansion) can have very interesting consequences, and thus demands our attention. This work will finally help in better arrival time predictions of CMEs on Earth as we work with their actual 3-D profiles (thus eliminating the discrepancies due to projection effects) and in turn provide valuable inputs for the observation plan of the ADITYA L1 mission which has the Visible Emission Line Coronagraph (VELC) onboard. |
