HR: 15:25h
AN: SM33E-07 INVITED     [Abstracts]
TI: An Information Theoretical Approach to Solar Flare Occurrence
AU: * Johnson, J R
EM: jrj@pppl.gov
AF: Princeton University, Princeton University Plasma Physics Laboratory PO Box 451 MS 28, Princeton, NJ 08543 United States
AU: Choe, G
EM: gchoe@pppl.gov
AF: Princeton University, Princeton University Plasma Physics Laboratory PO Box 451 MS 28, Princeton, NJ 08543 United States
AB: The distribution of waiting times between solar flare events provides information about whether flares occur as independent events and provides a test for flare statistics. The flaring time interval distribution can be fit reasonably well with the assumption that the distribution results from a nonstationary Poisson process that accounts for changes in the mean flaring rate on the order of days. The distribution may have relevance to understanding the underlying mode of energy release on the sun. Two possibilities are (a) that energy is released by a catastrophic process after the system builds up energy or (b) that the system is near marginal stability and undergoes an avalanche process in a self-organized critical state. It is considered that the latter is more likely based upon the lack of correlation between flare strength and waiting time. Although the flare occurrence distribution is well fit by a nonstationary Poisson process, that by itself does not establish that there are no relationships between successive flaring events. To examine whether there is such a dependency, we examined the mutual information between successive flaring time intervals. Surrogate data sets were constructed consistent with the assumption that the data are the result of a nonstationary Poisson process. The mutual information of the original data set is significantly larger than the surrogate data suggesting a dependency between successive flaring time intervals (in contradiction to the hypothesis of a Poisson process). After removal of periodicity in the data, the mutual information was reduced, but a significant residual remains. These results suggest that the common assumption that solar flares result from a nonstationary Poisson process is incorrect, and the results of our analysis may be useful for helping to identify the underlying mode of energy release on the sun.
UR: http://w3.pppl.gov/~jrj/flares.html
DE: 4430 Complex systems
DE: 7519 Flares
DE: 7536 Solar activity cycle (2162)
DE: 7833 Mathematical and numerical techniques (0500, 3200)
DE: 7839 Nonlinear phenomena (4400, 6944)
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005