viscosity
From Glossary of Meteorology
(Also called internal friction.) The transport of mass motion momentum solely by the random motions of individual molecules not moving together in coherent groups.
Viscosity is a consequence of gradients in velocity fields in fluids. Sometimes described as fluid friction because velocity gradients in fluids are damped as a consequence of viscosity.
See viscous force, stress tensor, dynamic viscosity, kinematic viscosity, Newtonian friction law, Navier– Stokes equations, eddy viscosity.
