AEROSOL AND OZONE DISTRIBUTIONS OVER THE WESTERN NORTH ATLANTIC DURING WATOX-86

On January 4, 6, 8, and 9, 1986, a series of National Oceanic and Atmospheric Administration WP-3D research flights was conducted over the western Atlantic Ocean 200-300 km off the coast of North America from Nova Scotia to Georgia as part of the Western Atlantic Ocean Experiment (WATOX). Rights were made perpendicular to NW airflow to establish the flux of gas and aerosol emissions off the North American continent to the ocean. Representative condensation nucleus (CN) concentrations averaged 150-250 cm(-3) in the free troposphere in clean conditions, but in atmospheric layers containing anthropogenic air pollution transported from long distances, CN concentrations reached 6500 cm(-3). In the marine boundary layer, CN concentrations averaged 500 to 750 cm(-3) under relatively clean conditions, and 1500 to 3000 cm(-3) in polluted air. Aerosol scattering extinction (b(sp)) ranged from 70 x 10(-6) m(-1) in the marine boundary layer to 20 x 10(-6) m(-1) in the free troposphere. Aerosol b(sp) was not as responsive to changes in atmospheric structure as CN although factor-of-2 changes across the marine boundary layer were observed. Aerosol size spectra in the marine boundary layer were an order of magnitude greater than those in the free troposphere. Consistent peaks in the volume spectra between 8 and 10 m diameter established the importance of sea salt as a major aerosol component. Ozone profiles in the free troposphere, normally in the 30-40 ppb range, exhibited laminae of enhanced concentrations (up to 70 ppb) at moisture boundaries, suggesting that active ozone production was occurring at these levels. Ozone concentrations within the marine boundary layer were generally lower than in the free troposphere.