Wind speed data

Full description

Field measurements of wind flow and sand transport were conducted over a low gradient (< 5°),

25 m wide beach, and concave to straight, low to moderate gradient (up to 31°), 200 m long, climbing

dune slope in southern Morocco. Velocity profiles and sand transport measurements were conducted

at 10 sites across this system. Site 1 was located on the flat beach, sites 2 and 3 on the gentle lower

slope (effective slope <5°), site 4 (9° effective slope), sites 5 and 6 (16-23° effective slope), and sites 6A

to 8 at the steepest upper portion of the slope (26-29° effective slope). Generally, the wind speed

increases significantly above site 4 and this increase is inversely proportional to the wind speed.

Although a slight deviation from log-linear is evident in the wind velocity profiles, they are essentially

log-linear, which results from the absence or low curvature of the dune’s slope over a long distance.

Regardless of slope inclination, when flow accelerates, the relative increase of wind speed with height

above the bed is higher. A total of 254 measurements of vertical mass flux distributions were analyzed,

and regardless of the site topography, a flat horizontal or inclined slope, all mass flux profiles are well

described by an exponential-decay function.