We present dynamos computed using a hybrid QG-3D numerical scheme in a thick spherical
shell geometry. Our model is based on a quasi-geostrophic convection code extended with …

Kinetic helicity and its spatial distribution are thought to be important for the maintenance of
a dipolar magnetic field in the geodynamo through the α-effect. Outside the inner core …

The preference for the axial dipole in planetary dynamos is investigated through the analysis
of wave motions in spherical dynamo models. Our study focuses on the role of slow …

The dipole–multipole transition in rapidly rotating dynamos is investigated through the
analysis of forced magnetohydrodynamic waves in an unstably stratified fluid. The focus of …

The liquid iron core of the Earth undergoes vigorous convection driven by thermal and
compositional buoyancy. The dynamics of convective fluid motions and heat transfer in such …

In recent numerical simulations of the geodynamo the dynamo action is driven, primarily, by
the effects of helicity, with differential rotation playing only a secondary role. These dynamos …

Kinetic helicity in most geodynamo simulations has a distinct distribution above and below
the equator—it is negative in the north and positive in the south. Using direct numerical …

Inertial waves are oscillations in a rotating fluid that arise due to the restoring action of the
Coriolis force. Low-frequency inertial waves are known to create columnar flow structures …

The generation and segregation of helicity in geodynamo simulations Page 1 On the generation
and segregation of kinetic helicity in geodynamo simulations Avishek Ranjan IIT Bombay, India …