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In 2015 the calculation of the International (Zurich) sunspot number was cancelled, and it was replaced by a new "recalibrated" series. A new data series was proposed also for the Group sunspot number. As a result, these two series which originally differed mainly in their long-term trends, were "reconciled", and the long-term trends in both of them were minimized. These changes led to new reconstructions of the long-term variations of solar irradiance, and to reconsidering the impact of the solar activity variations on climate change. Here we use data for the number of sunspots and the number of sunspot groups from a single observatory with continuous and homogeneous observations in order to evaluate how justified these recalibrations are., Proceedings of the XX Conference "Solar and solar-terrestrial Physics", pp. 61-66, 2016, ISBN 978-5-9651-1008-7, ISSN 0552-5829, 2016

Solar irradiance is considered one of the main natural factors affecting terrestrial climate, and its variations are included in most numerical models estimating the effects of natural versus anthropogenic factors for climate change. Solar wind causing geomagnetic disturbances is another solar activity agent whose role in climate change is not yet fully estimated but is a subject of intense research. For the purposes of climate modeling, it is essential to evaluate both the past and the future variations of solar irradiance and geomagnetic activity which are ultimately due to the variations of solar magnetic fields. Direct measurements of solar magnetic fields are available for a limited period, but can be reconstructed from geomagnetic activity records. Here we present a reconstruction of total solar irradiance based on geomagnetic data, and a forecast of the future irradiance and geomagnetic activity relevant for the expected climate change., Proceedings of the XVIII conference "Solar and Solar-Terrestrial Physics 2014", Pulkovo, Russia, 20-25 October 2014

The progress article - Widening of the tropical belt in a changing climate - by Seidel et al. (2008) published in the first issue of Nature Geosciences, summarizes the results of several methods to determine the width of the tropical zone. All they show evidence that the tropics have been expanding over the past few decades. We confirm this widening based on one more indicator - the position of the subtropical centers of high pressure. However, we question the implication of the authors that the tropics widen in response to human activity, and suggest as a more probable cause the increasing solar activity. Consequently, we question their conclusion that this widening may continue into the future in association with anthropogenic climate change, and suggest that whether the tropics will continue widening will depend on the future evolution of solar activity rather than on anthropogenic activity., Comment: 2 pages, 1 figure