The magnetic structure and geomagnetic response of 73 magnetic clouds (MC) observed by the WIND and ACE satellites in solar cycle 23 are examined. The results have been compared with the surveys from the previous solar cycles. The preselected candidate MC events were investigated using the minimum variance analysis to determine if they have a flux-rope structure and to obtain the estimation for...

UNLABELLED This paper describes the effects of radiation, probably ultraviolet radiation (UVR), on the human genome at peaks of solar cycles. This phenomenon was not previously reported because peak cycle lifespan had not been separated from non-peak lifespan. This paper reinforces the findings of others regarding the seasonality of various diseases and that there are factors occurring early in...

A review of solar cycle prediction methods and their performance is given, including forecasts for cycle 24. The review focuses on those aspects of the solar cycle prediction problem that have a bearing on dynamo theory. The scope of the review is further restricted to the issue of predicting the amplitude (and optionally the epoch) of an upcoming solar maximum no later than right after the sta...

The solar minimum between solar cycles 23 and 24 during the period 2007-2009 has been the longest and deepest one at least since for the last 100 years. We suggest that the Sun is going to his next supercenturial minimum. The main aim of this paper is to tell about arguments concerning this statement. They are based on series of studies, which have been provided during the period since 1997 up ...

A solar activity precursor technique of spotless event has been currently used to predict the strengths and the times of rise of the 11-year coming cycles. This simple statistical method has been previously applied to predict the maximum amplitudes and the times of rises of cycles 22 and 23. The results obtained are successful for both cycles. A developed version of the suggested method was pre...

The solar cycle is reviewed. The 11-year cycle of solar activity is characterized by the rise and fall in the numbers and surface area of sunspots. A number of other solar activity indicators also vary in association with the sunspots including; the 10.7 cm radio flux, the total solar irradiance, the magnetic field, flares and coronal mass ejections, geomagnetic activity, galactic cosmic ray fl...

Context. The Sun and solar-like stars undergo activity cycles for which the underlying mechanisms are not well understood. The oscillations of the Sun are known to vary with its activity cycle and these changes provide diagnostics on the conditions below the photosphere. Kepler has detected oscillations in hundreds of solar-like stars but as of yet, no widespread detection of signatures of magn...

We studied the Aa geomagnetic index (aa index daily average) behavior on a monthly timescale using data from 1868 to 2015 for cycles 11–24. We identified solarand lunar-associated periodicities in the Aa time series and found statistically significant Aa minima values a few days before the full Moon and high Aa values during the new Moon. When considering all the cycles, it was clear that the d...

NSSDC's OMNI dataset, which now spans 1963-1999, contains a collection of hourly means of interplanetary magnetic field (IMF) and solar wind (SW) plasma parameters measured near the Earth's orbit, as well as some auxiliary data. We report a study of solar cycle effects in planetary geomagnetic activity in which 27-day averages of several OMNI parameters are compared with equivalent Kp and Dst a...