Hydrodynamic helicity in Boussinesq-type models of the geodynamo

The generation of hydrodynamic helicity is considered in models of thermal convection of a rapidly rotating incompressible liquid (small Rossby numbers). It is shown that a system of cyclonic vortices arising in geodynamo models generates a large-scale hydrodynamic helicity. The spatial distribution of the helicity is analyzed as a function of the intensity of heat sources in models with various boundary conditions for the velocity field.