Helicity Production and Transfer in Rotating Convection

Helicity is believed to be important in controlling the dynamics in many fluid systems and can arise through rotation, through shear flows, or by mechanical means. It gives a measure of broken reflectional symmetry in a flow. In naturally occurring systems, helicity is important in dynamo action since the breaking of reflectional symmetry is important for large scale magnetic field generation in electrically conducting flows. In these systems it is important to know which scales in the flow manifest a breaking of reflectional symmetry, as indicated by the degree of relative helicity at that scale. For this reason there has been a lot of interest in how helicity is produced and transported between scales but focus has often been on systems with a turbulence driven by forcing at a localised scale. However, in many natural systems, the production of helicity is not localised and can depend on the flow dynamics and potentially even on the helicity distribution itself. One such system of great importance for our understanding of stars and planets is rotating convection. In this talk I will examine the production and transport of helicity as a function of thermal driving and rotation rate in rotating convection.