Influence of low-level wind speed on droplet spectra near cloud base in trade wind cumulus
Colón-Robles, M., Rauber, R. M., & Jensen, J. B. (2006). Influence of low-level wind speed on droplet spectra near cloud base in trade wind cumulus. Geophysical Research Letters, 33, L20814. doi:10.1029/2006GL027487
Data collected during the Rain In Cumulus over the Ocean (RICO) campaign demonstrate a relationship between the low-level wind speed, droplet concentrations and the presence of large cloud droplets near cloud base in trade wind clouds in a clean marine background atmosphere. Weak winds were assoc... Show moreData collected during the Rain In Cumulus over the Ocean (RICO) campaign demonstrate a relationship between the low-level wind speed, droplet concentrations and the presence of large cloud droplets near cloud base in trade wind clouds in a clean marine background atmosphere. Weak winds were associated with fewer activated cloud droplets, larger mean droplet sizes, and more large cloud droplets, even though the concentration of giant/ultragiant sea-salt aerosol increased with increasing near-surface wind speed. The data suggest that in unpolluted trade wind cumuli: (1) the production of large cloud droplets near cloud base is controlled primarily by the intensity of the cloud base updraft rather than the concentration of giant/ultragiant sea-salt particles; (2) higher droplet concentrations are more likely under conditions of stronger low-level wind speeds, primarily because stronger low-level wind speeds are associated with more intense cloud base updrafts. Show less