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Concentrations of lead, iron, nickel, copper, fatty acids, hydrocarbons, and chlorinated hydrocarbons are enriched from 1.5 to 50 times in the top 100 to 150 micrometers of Narragansett Bay water relative to the bulk water 20 centimeters below the surface. Trace metal enrichment was observed in the particulate and organic fractions but not in the inorganic fraction. If these substances are concentrated in films only a few molecular layers thick on the water surface, the actual enrichment factor in the films may be well over 10(4), resulting in extremely high localized pollutant concentrations in the surface microlayer.

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Shipboard (∼7 m) ozone measurements made in the equatorial Pacific Ocean between 20°N and 17°S and 140°–160°W confirm the existence of a distinct ozone minimum in the vicinity of the equator in the late spring, its decline in the summer, and its absence in autumn. This minimum could not be correlated with high biological activity in surface waters. Coincident aircraft measurements of ozone from near sea surface (50–100 m) to 2 km in altitude were made along 150°W at stations at 10°N, 0°, 5° and 12°S in May–June 1984. Aircraft data identified the existence of a distinct ozone maximum between the lifting condensation level (LCL) or cloud base (Zb) and the trade wind inversion, with ozone mixing ratios amounting to 2–2.5 times the ozone levels in the well‐mixed subcloud layer. A gradient of decreasing ozone with decreasing altitude extended from the LCL (or Zb) to the near‐surface superadiabatic region but did not include it.

Since 1977, several ship and aircraft expeditions to the equatorial Pacific have reported extremely low (-<10 ppbv) or undetectable levels of ozone within the marine boundary layer. Of necessity, field programs from mobile platforms are limited in both their temporal and spatial coverage. However, a 10-year record of observations at the geophysical monitoring for climatic change site in American Samoa suggests that low ozone mixing ratios are a common occurrence and may reflect a spatially variable but permanent region of low ozone in the equatorial Pacific. The spatial and temporal limits of this feature as well as some aspects of the intensity of the minimum appear to be maintained by the large-scale atmospheric circulations of the equatorial Pacific. Perturbations in the large-scale circulations as well as episodic events are reflected in observations of 03 in the equatorial Pacific. Variations in the large-scale, zonal circulation patterns (i.e., Walker circulation) of the equatorial Pacific appear to have a major influence on the spatial distribution of 03 across the equatorial Pacific. The relative importance of variations in large-scale, meridional circulation patterns on the distribution of 03 in the tropical Pacific is uncertain; however, they may be important at latitudes somewhat removed from the equator such as at American Samoa. 18,679 18,680 PIOTROWICZ ET AL.' OZONE OVER THE EQUATORIAL PACIFIC OCEAN latitudinal and vertical distribution of tropospheric ozone over the Atlantic Ocean in the southern and northern hemispheres, in Ozone in the Atmosphere, edited by R. D. Bojkov and P. Fabian, pp. 419-422, A. Deepak, Hampton, Va., 1989. Zipser, E. J., Mesoscale and convective-scale downdrafts as distinct components of squall-line structure, Mon. Wea. Rev., 105, 1568-1589.