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During the last few years the Sun and solar wind have shown a behavior that was so unexpected that the phenomena was described as 'the strange solar minimum'. It has been speculated that the 23/24 solar cycle minimum may have indicated the onset of a Maunder-Minimum-type Grand Minimum. Here we review what is known from 1500 years of proxy data about Maunder-type Grand Minima and the minima of the cyclic Centennial Gleissberg variations. We generate criteria that distinguish between the two types of event. Applying these criteria to the observed solar terrestrial data we conclude that the unexpected behavior began well before the solar cycle 23/24 minimum. The data do not support the Maunder Minimum conjecture. However, the behavior can be understood as a minimum of the Centennial Gleissberg Cycle that previously minimized in the beginning of the 20th century. We conclude that the Centennial Gleissberg Cycle is a persistent variation that has been present 80% of the time during the last 1500 years and should be explained by solar dynamo theory. [ABSTRACT FROM AUTHOR]

Abstract: The high-energy solar proton data obtained from instruments onboard the IMP-8 spacecraft are used to investigate statistical distributions of event fluences, event durations, and time intervals between adjacent events. The results show that: (1) the event fluences can be approximately fit to a log-normal distribution and (2) the distributions of event durations and time intervals between the events can be represented by Poisson distributions. A virtual data set was generated using these distributions to extend the Solar Probe method [Feynman, J., Tylka, A.J., Reames, D.B., Gabriel, S.B. Near-sun energetic particle environment of Solar Probe-Phase1 final report, JPL Report, 2000] of obtaining the mission-integrated fluences to longer missions. By using the virtual data set generated in this study, we are able to obtain the smooth distribution of mission fluences for missions of any duration, which is not possible when only the available data sets was used. [Copyright &y& Elsevier]