Convection transports properties such as energy or composition through bulk fluid motion. Thermal convection is driven by temperature-dependent buoyancy.
Thermal convection is fluid motion driven by temperature-dependent buoyancy. It transports heat by bulk motion in addition to thermal conduction.
A stable stratification gives a restoring buoyancy force and positive squared buoyancy frequency for an adiabatically displaced parcel. An adverse specific entropy gradient can instead drive convection; other forces such as rotation can modify the full stability criterion.
Convective overshoot carries material from an unstable convecting region into an adjacent stably stratified region because its momentum does not vanish at the stability boundary. In stars this mixes material beyond the boundary determined by a local stellar convective stability criterion, changing stellar core masses and nuclear lifetimes.
Double-diffusive convection occurs when two properties, such as temperature and composition, affect buoyancy but diffuse at different rates. A stabilizing composition gradient can oppose a destabilizing thermal gradient and change the form of heat transport.
Layered convection consists of mixed convecting layers separated by more weakly transporting interfaces. In a giant planet, composition gradients can support such interfaces and reduce heat loss, contributing to delayed cooling of an inflated giant planet.
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Convection is a mode of heat transfer that occurs in fluids (liquids and gases) and is characterized by the movement of molecules within the fluid. In convection, warmer areas of a fluid become less dense and rise, while cooler areas become denser and sink. This movement creates a continuous circulation pattern that helps redistribute heat throughout the fluid.