Journal of Geophysical Research (1990) 95: 1789-1795.
Received: 24 February 1988.
Revised: 25 July 1989.
Accepted: 25 September 1989.
Published: 20 February 1990.
Biomarker source information provided by long-chain alkenone (LCA) distribution patterns was used to assess the transport pathways of marine aerosols. The C37-C39 LCAs were found in significant amounts in aerosols collected in New Zealand. Their occurrence in the atmosphere stems from their introduction by bubble-bursting processes during wave breaking. The surface water temperatures calculated from the Uk-37 ratios suggested a local origin and short atmospheric residence times of the LCAs. They were not detected in aerosol samples collected on American Samoa due to the absence of the source organisms in surface waters upwind. The distribution of LCAs was also investigated in size-fractionated aerosols over a range of <0.5 to >7.2 µm equivalent diameter. Their distribution over the size spectrum demonstrated that they were only associated with large particles (d-eq > 3.0 µm), suggesting a direct injection of algal cells and/or their fragments into the atmosphere.
We thank the Oceanography and Atmospheric Sciences sections of the National Science Foundation for support as part of the SEAREX program (OCE 84-06666) as well as the Ministère des Affaires Etrangères, France, for financial support for M.-A. Sicre. The meteorological calculations were performed by J. T. Merrill using computer facilities at the National Center for Atmospheric Research, also supported by NSF. We thank J. R. Ertel, J. W. Farrington and J. P. Jasper for critical comments improving this manuscript. Special thanks to N. A. Hayward and C. G. Johnson for assistance in the analytical work. This is Woods Hole Oceanographic Institution contribution number 6724.