Editing Advection (section)

==Distinction between advection and convection==
[[File:Heat-transmittance-means2.jpg|thumb|250px|The four fundamental modes of heat transfer illustrated with a campfire]]
The term ''advection'' often serves as a synonym for ''[[convection]]'', and this correspondence of terms is used in the literature. More technically, convection applies to the movement of a fluid (often due to density gradients created by thermal gradients), whereas advection is the movement of some material by the velocity of the fluid. Thus, although it might seem confusing, it is technically correct to think of momentum being advected by the velocity field in the Navier-Stokes equations, although the resulting motion would be considered to be convection. Because of the specific use of the term convection to indicate transport in association with thermal gradients, it is probably safer to use the term advection if one is uncertain about which terminology best describes their particular system.