Jy. Sheng et Ae. Hay, SEDIMENT EDDY DIFFUSIVITIES IN THE NEARSHORE ZONE, FROM MULTIFREQUENCY ACOUSTIC BACKSCATTER, Continental shelf research, 15(2-3), 1995, pp. 129-147
Acoustic backscatter measurements made on the seaward face of a submer
ged nearshore bar are used to determine the vertical eddy diffusivity
profile for sand in suspension. Suspended sand size and concentration
estimates, obtained from the multifrequency backscatter inverse, permi
t the sediment eddy diffusivity to be determined by assuming a balance
between settling and vertical diffusion after correcting for the vert
ical wave flux. The resulting diffusivity profiles exhibit a nearbed l
inear region scaling approximately with the mean maximum friction velo
city. Above this region, the data do not collapse to a universal form
using a single vertical length scale.