Wave-induced bed shear-stress from Swart (1976)
It is customary to compute the wave-induced bed shear-stress from the maximum orbital velocity near the seabed and a wave friction factor, fw. Swart (1976) formulation has been chosen to compute fw in GAIA (subroutine tobw_gaia.f).
However, the coefficients in his original formulation have been truncated. Now I don't suspect that it will make much difference to the overall result, but I can't think of any reason why that is.
The original equation reads: FW(I)=MAX( EXP( -5.977D0 + 5.213D0 * (A0/R)**(-0.194D0) ) , 0.30D0 )
The manual for GAIA (p44) would need to be updated as well to reflect the correct formulation.
Edited by Noémie Durand