Convection

Vertical motion within the atmosphere due to thermal instability, with important impacts on the type cloud systems that can develop.

Convection Atmospheric motions that are predominantly vertical, resulting in vertical transport and mixing of atmospheric properties; distinguished from advection.

The movement of matter due to changes in temperature and density. Warm material rises because it is less dense (lighter) and cool material sinks because it is denser (heavier).

The transfer of heat by means of air currents.

Generally, transport of heat and moisture by the movement of a fluid.

In meteorology, the term is used specifically to describe vertical transport of heat and moisture in the atmosphere, especially by updrafts and downdrafts in an unstable atmosphere. The terms "convection" and "thunderstorms" often are used interchangeably, although thunderstorms are only one form of convection. Cbs, towering cumulus clouds, and ACCAS clouds all are visible forms of convection. However, convection is not always made visible by clouds. Convection which occurs without cloud formation is called dry convection, while the visible convection processes referred to above are forms of moist convection.