Yavor Chapanov, Cyril Ron and Jan Vondrak. Decadal Cycles of Earth Rotation, Mean Sea Level and Climate, Excited by Solar Activity. Acta Geodyn. Geomater., Vol. 14, No. 2 (186), 241–250, 2017 DOI: 10.13168/AGG.2017.0007
The solar activity affects all surface geosystems, including weather and climate indices, winds, rains, snow covers, mean sea level, river streamflows and other hydrological cycles. The mean sea level and polar ice changes cause common variations of the principal moments of inertia and Earth rotation with decadal, centennial and millennial periods. The mean sea level, Earth rotation
and climate indices have also some oscillations with periods below 40 years, whose origin is not connected with the known tidal and solar effects. The shape of solar cycles is rather different from sinusoidal form, so they affect geosystems by many short-term harmonics. A possible solar origin of decadal variations of Earth rotation, mean sea level and climate indices is investigated by the harmonics of Jose, de Vries and Suess cycles with centennial periods of 178.7, 208 and 231 years. The common decadal cycles of solar-terrestrial influences are investigated by long time series of Length of Day (LOD), Mean Sea Level (MSL) variations at Stockholm, ElNiño/Southern Oscillation (ENSO), temperature and precipitation over Eastern Europe, Total Solar Irradiance (TSI), Wolf’s Numbers Wn and North-South solar asymmetry. A good agreement exists between the decadal cycles of LOD, MSL, climate and solar indices whose periods are between 12-13, 14-16, 16-18 and 28-33 years. The new linear models of the decadal
common Earth and solar cycles may help for long term forecasts of many global and local changes.