A Comparative Study Of The Coastal Marine Aerosol

Aerosol size distributions near the coast of Panama City, Florida and off the Southern California coast near the Channel Islands are investigated in this study. The relationships of the coastal marine aerosol to wind speed, relative humidity, stability, and sub-synoptic circulation are examined. Relative humidity and stability are shown to have the largest effect on the aerosol distribution during periods of light winds. Coalescence and sedimentation of droplets greater than 1.5 micrometer radius are most pronounced when the wind speed and sea surface production of salt nuclei are weak. When wind speeds exceed 7 m/sec, a state of equilibrium between sedimentation and production of these larger droplets appears to exist. An apparent zone of transition between the two bubble bursting sea-salt producing mechanisms is observed near .5 micrometer radius. The highest correlation betwwen wind speed and particle concentration occurs under unstable conditions. Secondary circulations are shown to be important determinants of the coastal marine aerosol in the absence of synoptic scale forcing. (Author).