ИСТИНА

Gravity Recovery and Climate Experiment (GRACE) satellites, launched, 17.03.2002 from Plesetsk, provide a set of monthly Earth’s gravity field observations. They present a big interest for hydrological studies. Gravity and data reflect changes, related to groundwater redistribution, ice melting, and precipitation accumulation. However, de-stripping/filtering is required to use the GRACE data products. We apply Multichannel Singular Spectrum Analysis (MSSA, or extended EOF) technique to filter GRACE data and separate the principal components (PCs) of different periods. We performed data averaging over the large river basins of Russia. Winter 2012-2013 was the most snowy winter in Russia since 1960s. Melting of this snow induced large floods and river levels increase. The exceptional maxima are seen in the curves obtained from GRACE. Next spring and summer 2014 were much less snowy. Long-periodic climate-related changes were separated into PC 2. Gravity field increase in Siberia, Black sea, and decrease around Caspian sea are seen. We compare GRACE results with measurements made by absolute gravimeters in several regions of Russia. Local trends in the gravity field were found to be similar.