The Periodicities of Solar X-ray Flares and Coronal Mass ejections during Solar Cycle 23

Abstract

The Events of energetic particles from solar X-ray flares and shock waves have been studied. The data were taken from the National Geophysical data center (NGDC) in Boulder, Colorado, USA, Where the data were taken during the solar cycle 23rd. The 23rd cycle is the present one, that started in April 1996, and its maximum was in May 2001, and it will be decayed during year 2007. Power spectrum methods have been applied for analysis of the data given, to find the short and intermediate periodicities. The periodicity around 14 days has appeared in this analysis. This has important implications for understanding and predicting the effects of solar activity on the Earth and on the earth’s atmosphere. If a Coronal Mass Ejections (CMEs) hit the Earth, it can excite a geomagnetic storm. Large geomagnetic storms, among other things, can cause electrical power which can damage satellite communications. In space CME typically drive shock waves that produce energetic particles that can damage both electronic equipment and astronauts that are outside the protection of the Earth’s magnetic field. So, the prediction of the high energetic particle events is of vital importance for space navigation and airline disasters. 1. Method and Analysis The data of events occurred during solar cycle 23rd, were taken from the National Geophysical data center (NGDC) in Boulder, Colorado, USA. The method of power spectrum analysis of the data has been used for all data analysis, where the squared amplitudes [aν ] are taken as the power of the frequency ν, as follows: [aν ] = ( ∑N−1 i=0 r(i) cos(2πi) )2 + ( ∑N−1 i=0 r(i) sin(2πi) )2 N2 Where N is the total number of X-ray flares events, equal to 6483 events in solar Xray calculations of power spectrum. By using hamming function the data have been smoothed, where the resolution power spectrum given as: rn = 0.23rn−1 + 0.54rn + 0.23rn+1 For more details about the method of analysis, see for example, Hady A. (2002), and Rieger et al (1984).The relative error values are calculated according to: