Dry deposition of particles to wave surfaces: II. Wind tunnel experiments

Wind tunnel measurements of particle dry deposition to wavy and flat surfaces were made to estimate the enhancement of deposition rates due to waves on water surfaces. Measurements were made of 4.0 and 6.7 μm uranine particles at wind speeds of 5 and 10 m s−1 to sinusoidal waves with height to length ratios 2a/λ=0.1 and 0.03 and to flat surfaces. Results showed that deposition was greatest to the upslope portion of the wave, accounting for 40–45% of the total mass, followed by the trough (30%), downslope (15%), and crest (10–15%). These results generally agreed within experimental variability with modeling predictions (Zufall et al., 1999). Deposition was enhanced at the upslope due to the effects of particle interception and impaction on the wave. Total deposition to the wave surfaces was greater than deposition to the flat surface for a large majority of the cases. The average increase in deposition to both wave surfaces for both particle sizes and wind speeds over deposition to the flat surface was 80%.