Abstract Details
| Name: Urmi Doshi Affiliation: M.P.Birla Institue of Fundamental Research, Bangalore Conference ID: ASI2016_389 Title : On the geomagnetic storms associated with isolated halo CMEs Authors and Co-Authors : Urmi Doshi(M.P.Birla Institue of Fundamental Research, Bangalore & The Maharaja Sayajirao University of Baroda, Baroda), Ramesh K.B.(Indian Institute of Astrophysics, Bangalore) and Babu G.S.D.(M.P.Birla Institute of Fundamental Research, Bangalore) Abstract Type : Poster Abstract Category : Sun and the Solar System Abstract : In the present study, we have analyzed the behavior of 23 moderate to intense geomagnetic storms with Dst (Disturbance Storm Time) ≤ -50 nT that have clearly identifiable Sudden Storm Commencement (SSC) and are specifically associated with isolated halo CMEs (Coronal Mass Ejections) erupted during the years 1997 to 2011. Our analysis with the CME parameters such as speed of the CME (V), latitude & longitude of the source region and the duration for which the Bz (z–component of the Interplanetary Magnetic Field) was southward during the storm phase indicated that the southward turning of Bz before the main phase of the storm plays a vital role in deciding the intensity of the storm, rather than the consistent southward Bz during the actual main phase,. Also, a weak correlation has been noticed between the linear CME speed (V) and the peak amplitude of the storm which may imply that not all intense storms are associated with large CME speeds. Further, we find that though the CMEs arising from the +/- 30 helio-latitude regions are generally effective in causing the storms, the source regions of CMEs as such do not seem to play a critical role in deciding the strength of the storms. |