Lozitska N. Secular variations of the sunspot magnetic fields and their manifestations in the interplanetary space and geosphere.

The thesis contains results of the statistical analysis of 20 000 magnetic field measurements in sunspots, observed between 1920 and 2010. As inclusion criteria for sunspot selection, their diameter from 30 to 60 arc.sec was chosen. New solar index Вsp have been introduced as a yearly averaged module of magnetic fields of such sunspots, calculated from daily observational data of several observatories, including Kyiv Taras Shevchenko University, Mt. Wilson, Crimean, Pulkovo observatories, etc. Significant interannual changes of the Bsp index were revealed, ranged from 21 to 27 cT, that are 10 times larger than measurements' errors. Average value of Bsp during 1920-2010 is 24.9 сТ. Variations of Bsp are accompanied by changes of annual-averaged dimension of individual spots. Strong correlation between more shot rows of Hm, Bav indices and Bsp was found.Significant N-S-disbalance of 3-year averages of sunspots' magnetic field values at entire solar disk (absolute asymmetry) with amplitudes of 1-3 cT, area asymmetries of 300-900 m.p.h. and average latitudes of 2-6° are shown. All mentioned indexes have amplitudes, modulated by the centenary cycle and 7-9-year period. Sunspots' area asymmetry changes advance magnetic field disbalance changes by 2-3 years, while latitudinal differences lag magnetic field one by 2 years. These results agree with some theoretical studies, concluding existence of the two magnetic field generation zones of the Sun. Obtained correlation between running 44-years averaged (by Gleisberg method) sunspot numbers and magnetic field is r = -0.87. Secular variations of sunspot number allows to predict that SSNmax will be 90±30 during 24-26 cycles and smoothed by 44-years spot number will decrease on 40, as compared to the period of SSN secular maximum in the XX century. Coming from named prediction of the SSN, one can expect that Bsp index will increase on 1.0 сТ and will reach 25.5±0.1 сТ. Bsp and surface Earth temperature T were compared; significant correlation between them was revealed. These results indicate that global warming of the Earth's climate observed since about 1975 may be caused by secular increase of the solar magnetic flux.