In the case of scalar fluxes, such as potential temperature and water vapour, it has been shown that non-local transport plays an important role in the turbulent transport, implying that a purely diffusive representation is insufficient. Counter-gradient, mass-flux theories and the combined eddy-diffusivity/mass-flux (EDMF) scheme were built to overcome that problem. The role of non-local effects in momentum is still largely an opened question.
In the present study we use results from LES simulations to diagnose vertical profiles of momentum fluxes in different convective boundary layers: the nieuwstadt clear boundary layer, the trade wind cumulus BOMEX case, the shallow cumulus diurnal cycle from the ARM experiment and a LBA shallow convection case. In many situations these results show that the momentum transport made by organized updraughts contribute significantly to the total turbulent flux, suggesting that they may be included in convective parametrizations. The vertical turbulent flux partition dependency on the shear is also explored.