In this work a new information resource located at http://www.gao.spb.ru/database/esai and hereinafter referred to as ESAI ("Extended time series of Solar Activity Indices") is presented. ESAI includes observational, synthetic and simulated sets to study solar magnetic field variations and their influence on the Earth. ESAI extends the ordinary lengths of some traditional indices, parameterizing time variations of physically different characteristics of solar activity. In particular, long-term sets of the following indices are presented: sunspot areas, the Wolf numbers, polar faculae numbers, sunspot mean latitudes and north-south asymmetry of hemispheres for different components of activity. Some methods for making correct conclusions from incomplete data and some criteria to estimate the reliability of the obtained information are discussed.
Based on the extended Greenwich -NOAA/USAF catalogue of sunspot groups, it is demonstrated that the parameters describing the latitudinal width of the sunspot generating zone (SGZ) are closely related to the current level of solar activity, and the growth of the activity leads to the expansion of the SGZ. The ratio of the sunspot number to the width of the SGZ shows saturation at a certain level of the sunspot number, and above this level the increase of the activity takes place mostly due to the expansion of the SGZ. It is shown that the mean latitudes of sunspots can be reconstructed from the amplitudes of solar activity. Using the obtained relations and the group sunspot numbers by Hoyt and Schatten (Solar Phys. 179, 189, 1998), the latitude distribution of sunspot groups ("the Maunder butterfly diagram") for the eighteenth and the first half of the nineteenth centuries is reconstructed and compared with historical sunspot observations.
We study and compare characteristics of sunspot group latitude distribution in two catalogs: the extended Greenwich (1874-2014) and Schwabe ones (1825-1867) [1]. We demonstrate that both datasets reveal similar links between latitude and amplitude characteristics of the 11-year cycle: the latitude dispersion correlates with the current activity and the mean latitude of sunspots in the cycle's maximum is proportional to its amplitude, It agrees with conclusions that we made in papers [2, 3] for the Greenwich catalog.We show that the latitude properties of sunspot distribution are much more stable against loss of observational data than traditional amplitude indices of activity. Therefore, the found links can be used for estimates of quality of observations and independent normalizing of activity levels in a gappy pre-Greenwich data. We demonstrate it using the Schwabe catalog as an example.In addition, we show that the first part of the Schwabe data probably contains errors in determination of sunspot latitudes that lead to overestimation of the sunspot latitude dispersions.
Using proxy series that includes ancient observations of sunspots and auroras, concentrations of cosmogenic isotopes 14 C and 10 Be, we reconstruct sunspot activity level since 850 AD to the present. As a main reference index of solar activity we use the Wolf sunspot numbers, which, as we demonstrate, reflect true levels of the activity in the 18th and 19th centuries better than the Group sunspot numbers. We construct a set of linear and nonlinear inductive models, which are in a good agreement with each other and reproduce the known global solar activity extrema. According to our results, amplitudes of the global maxima are in intermediate positions in respect to estimations of other authors. It follows from our reconstructions that the global maximum of the 20th century is not much higher, if at all, than others.
Based on the extended Greenwich-NOAA/USAF catalogue of sunspot groups it is demonstrated that the parameters describing the latitudinal width of the sunspot generating zone (SGZ) are closely related to the current level of solar activity, and the growth of the activity leads to the expansion of SGZ. The ratio of the sunspot number to the width of SGZ shows saturation at a certain level of the sunspot number, and above this level the increase of the activity takes place mostly due to the expansion of SGZ. It is shown that the mean latitudes of sunspots can be reconstructed from the amplitudes of solar activity. Using the obtained relations and the group sunspot numbers by Hoyt and Schatten (1998), the latitude distribution of sunspot groups ("the Maunder butterfly diagram") for the 18th and the first half of the 19th centuries is reconstructed and compared with historical sunspot observations.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.