title: Fluid motions in the Earth's core inferred from time spectral features of the geomagnetic field.
abstract: The aim of this work is to investigate the time spectral features of the main geomagnetic field fluctuations as measured on the Earth's surface in connection with a nontraditional turbulent dynamics of the fluid motions in the outer layers of the Earth's liquid core. The average geomagnetic field spectrum is found to be a power law, characterized by a spectral exponent alpha approximately -11/3, on time scales longer than 5 yr. We discuss the spectral exponent in connection with an intense magnetic field in the Earth's core and with a vortex coalescence process in a regime of drift-wave turbulence.
authors.affiliation: Istituto di Fisica dello Spazio Interplanetario, CNR, I-00133 Roma, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Consolini
authors.forename: Paola
authors.initials: P
authors.lastname: De Michelis
authors.forename: Antonio
authors.initials: A
authors.lastname: Meloni