Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation of the Russian Academy of Sciences
Russian Federation
UDK 55 Геология. Геологические и геофизические науки
UDK 550.34 Сейсмология
UDK 550.383 Главное магнитное поле Земли
GRNTI 37.01 Общие вопросы геофизики
GRNTI 37.15 Геомагнетизм и высокие слои атмосферы
GRNTI 37.25 Океанология
GRNTI 37.31 Физика Земли
GRNTI 38.01 Общие вопросы геологии
GRNTI 36.00 ГЕОДЕЗИЯ. КАРТОГРАФИЯ
GRNTI 37.00 ГЕОФИЗИКА
GRNTI 38.00 ГЕОЛОГИЯ
GRNTI 39.00 ГЕОГРАФИЯ
GRNTI 52.00 ГОРНОЕ ДЕЛО
OKSO 05.00.00 Науки о Земле
BBK 26 Науки о Земле
TBK 63 Науки о Земле. Экология
BISAC SCI SCIENCE
It is shown that during reversals in geodynamo models the minimum amplitudes of the dipole, quadrupole and octupole coincide. Since the characteristic time of the reversal is close to the oscillations of the large-scale geomagnetic field, a similar analysis was carried out for the minima of the amplitude of the dipole magnetic field over the past 100 thousand years. It turned out that in this case such synchronization also occurs. It can be assumed that reversals and large scale variations of the geomagnetic field between the reversals have a lot in common. The wavelet analysis carried out indicates that the concept of the main geodynamo cycle is very arbitrary: the period of oscillation can vary from 8–10 thousand years to 20–30 thousand for a dipole. Analysis of the evolution of the Mauersberger spectrum allows us to conclude that magnetic field fluctuations observed at the Earth’s surface are associated with the transfer of the magnetic field to the surface of the liquid core and can hardly be described by functions periodic in time.
geodynamo, core-mantle boundary, magnetic field modes synchronization
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