A statistical study of soft X-ray flares during solar cycle 22

Details A statistical study of soft X-ray flares during solar cycle 22 A statistical study of soft X-ray flares during solar cycle 22

Jul 2002

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002jnuns..38..457y&link_type=abstract

Journal of Nanjing University (Natural Sciences) [Nanjing Daxue Xuebao (Ziran Kexue)] (ISSN 0469-5097), Vol. 38, No. 4, p. 457 -

Statistics

1

Sun, X-Ray Flares, Class, Power-Law Index, Optical Counterpart

Scientific paper

Solar flares are among the most energetic events on the Sun. The eruption of solar flares has a great influence on the space environment and the Earth. A statistical study of flares occurring in a whole solar cycle is important in understanding the main characteristics of flares and useful for further study on the flare mechanism. In this paper, we make a complete statistics of the soft X-ray (SXR) flares during solar cycle 22 according to the GOES satellite data. Among the 20930 flares, less than 1% belong to X-class, 10% to M-class, and about 60% to C-class. The flare activity in this cycle undergoes a similar behavior to the sunspot number and experiences two peaks in 1989 and 1991, in which the mean flare index is 426 and 468, respectively. The numbers of flares of C-, M-, and X-classes increase rapidly during the ascending phase of the solar cycle, and decrease slowly during the decay phase. The ascending phase takes only about 2 years while the descending phase more than 4 years. The occurrence ratio of flares has a power-law distribution in dependence on the peak soft X-ray flux; the average power-law index for dN/dF, where N is the number of flares and F is the peak flux, is about -2.135 and the correlation coefficient is -0.987. Smaller (B-class and some C-class) flares are affected by the background noise so that they are not included in the derivation of flare index. Moreover, the percentage of SXR flares that have optical counterparts increases with the soft X-ray flux which amounts to 94% for X-class, 83% for M-class, 63% for C-class, and only 30% for B-class, respectively.

Affiliated with

Also associated with

No associations

Rating

A statistical study of soft X-ray flares during solar cycle 22 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with A statistical study of soft X-ray flares during solar cycle 22, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A statistical study of soft X-ray flares during solar cycle 22 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-735072