Alexander Bershadskii

It is shown that helicity dynamics dominates the thermal convection-driven geomagnetic field variability. The notion of the distributed chaos has been used for this purpose. The large-scale circulation in the Earths outer (metallic liquid) core is especially sensitive to the helicity dynamics and its chaotic reversals can be associated with the reversals of the mean helicity sign (the ergodic restoration of the reflectional symmetry in a long run). Results of numerical simulations, laboratory and atmospheric experiments, and observations of the crustal (the World Magnetic Anomaly Map) and paleomagnetic fields (the geomagnetic field dipole variability and reversals) have been used in order to support the theoretical considerations based on the adiabatic invariance of the second order moment of the helicity distribution.