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Variations of coronal mass ejections and solar proton events (E >10 MEV)
P RAYCHAUDHURI
Published in Tata Institute of Fundamental Research
2005
Volume: 1
   
Pages: 153 - 156
Abstract
We study the preliminary list of coronal mass ejections (CMEs) events observed by SOHO / LASCO from the beginning of 1996 to the end of 2003 and find that the occurrence of average CME rate is 121.15 per month during June 1999 to June 2003 (sunspot maximum range) and that the occurrence of average CME rate is 41.24 per month during 1996 to May 1999 (sunspot minimum range). We find also that the average speed of CME during sunspot maximum range is 496 km / sec. whereas average speed of CME during sunspot minimum range is 338 km / sec. The CME speed is also correlated with sunspot number with less significant level than the average rate of CME occurrence. The average speed of CME is possibly related to the solar radius variation which may indicate that the perturbed nature of the solar core may be their common origin We collect also the preliminary list of halo CME from SOHO / LASCO during 1996 to 2003 and find that occurrence rate of average halo CME during the sunspot minimum range is about 1.10 / month whereas during sunspot maximum range about 4.10 per month. We also find that the average speed of halo CME events is about 838 km / sec during sunspot minimum range whereas to maximum range is about 1000 km / sec. We also study the preliminary list of solar proton events (E > 10 MeV) that are occurred almost during halo CME events and find that there are six events with high proton flux during the sunspot maximum range which are responsible for strong geo-magnetic storms. From the solar proton event we find five phases of solar proton events during the solar activity cycle. We have also studied magnetic clouds (MC) data from the year 1996 to 2003 and found that they exhibit periods around 7 and 32 months.
About the journal
Journal29th International Cosmic Ray Conference, ICRC 2005
PublisherTata Institute of Fundamental Research