Noun
English Wikipedia has an article on:gravitational convectionWikipedia
gravitational convection (countable and uncountable, plural gravitational convections)
(physics) The convection (carriage) of contents of a fluid, such as mass or heat, by means of currents induced in the fluid by buoyancy forces which are dependent on gravity acting upon density differences within the fluid.
Gravitational or buoyant convection Gravitational convection is a type of natural convection induced by buoyancy variations resulting from material properties other than temperature. Source: Internet