First Coefficients of Expansion into Spherical Functions of the Surface Atmospheric Pressure of the European Reanalysis Project (ERA5)

Abstract

From the ERA5 reanalysis data, the time series of the first coefficients ( $$C_{0}^{0}$$ , $$C_{1}^{0}$$ , $$C_{1}^{1}$$ , $$S_{1}^{1}$$ , $$C_{2}^{0}$$ , $$C_{2}^{1}$$ , and $$S_{2}^{1}$$ ) of expansion of the surface atmospheric pressure into spherical functions for 2000–2018 with a temporal resolution of 1 h are calculated. The values of these coefficients are used to calculate the average mass of the atmosphere, its seasonal changes, and the loading gravimetric effect due to these changes, as well as the vertical loading shifts of the Earth’s surface. The series of coordinates of geocenter motion, as well as the excitation functions of the atmospheric angular momentum, are obtained.