The Empirical Implication of Conducting a Chree Analysis Using Data from Isolated Neutron Monitors
The analysis method developed by Chree has received several critical reviews since its introduction in geophysical studies (Chree in Philos. Trans. Roy. Soc. London, Ser. A, Contain. Pap. Math. Phys. Character212, 75, 1912). Several of these critiques, such as those by Forbush et al. (Solar Phys. 82, 113, 1983), point to the test of significance of epoch superposition results. Forbush events are a key event time used in space weather investigations. Despite the early indications of Marz (J. Atmos. Solar-Terr. Phys. 59, 957, 1997) that the result of a compositing analysis depends on the method of Forbush decrease (FD) date selection, the various conflicting methods of key event date selection appearing in the publications that document an FD-based epoch analysis are yet to be cross-examined in detail. This is the goal of the present submission.
KeywordsCosmic rays Forbush decreases Cosmic ray stations Chree analysis Statistics Fourier transformation Significance test Critiques Algorithms Simultaneity of Forbush decreases
We feel indebted to the groups maintaining the websites http://www.nmdb.eu and http://cr0.izmiran.rssi.ru/ . The first author acknowledges the kind assistance of James Arthur Lemon, University of New South Wales. The present analyses benefited so much from his great expertise in R for Statistical Computing software. The thought-provoking queries of the anonymous referees led to significant improvements of the manuscript. Their time and efforts are acknowledged with thanks.
Declaration of Potential Conflicts of Interest
The authors declare that they have no conflicts of interest.
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