Climate dynamics and interdecadal discharge fluctuations in the Ural River basin

Abstract

Data gathered from the mean annual water expenditures of the Ural River basin, obtained at 15 hydrological stations over a 70-year observation period was used to analyze its water content fluctuations and the correlation of discharge oscillations with different climate indices. Based on the Morlet-6 wavelet, the method of continuous wavelet transformation was applied to reveal latent periodicities in the discharge series. To establish factors responsible for discharge cycles, a cross wavelet analysis was performed on solar activity, types of Vangengeim atmospheric circulation, and three climate indices: the Atlantic Multidecadal Oscillation, the North Atlantic Oscillation, and the Arctic Oscillation.