In fluid dynamics, the radiation stress is the depth-integrated - and thereafter phase-averaged - excess momentum flux caused by the presence of the surface gravity waves, which is exerted on the mean flow.
Conservation equations for mass flux (including entrainment) and momentum flux (allowing for buoyancy) then give sufficient information for many purposes.
Although speculative, ideas such as coupling to the momentum flux of the zero-point electromagnetic wave field hypothesized in stochastic electrodynamics have a plausible basis for further investigation within the existing theoretical physics paradigm.
Enhanced surface moorings with extra instruments to "more precisely define surface heat, moisture, and momentum fluxes" in addition to downwelling longwave radiation and barometric pressure.
Detailed studies of evaporation involve boundary layer considerations as well as momentum, heat flux and energy budgets.
Load and moment boundary conditions involve higher derivatives of and represent momentum flux.
Inner-scale scintillometers can also measure the dissipation rate of turbulent kinetic energy and the momentum flux.
Mesh refinement captures the complex flow features that occur at the leading edge of a flow, as well as locations where rapid changes in topography induce large mass and momentum fluxes.
A simple model of the surface layer can be derived by first examining the turbulent momentum flux through a surface.
It is possible for momentum flux to occur even though the wave itself does not have a mean momentum.