Aerosol bacteria over the Southern Ocean during ACE-1

• Published in: Atmospheric Research
• Main Authors: Pósfai, Mihály, Li, Jia, Anderson, James R., Buseck, Peter R.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2003
• Subjects: QD06 Mineralogy / ásványtan; QE Geology / földtudományok; Grim; Southern Ocean
• Online Access: https://real.mtak.hu/3407/; https://real.mtak.hu/3407/1/1038997.pdf; https://doi.org/10.1016/S0169-8095(03)00039-5

Individual bacterial cells occur in many samples that were collected at Cape Grim, Tasmania and during the Lagrangian "B" experiment of the Aerosol Characterization Experiment 1 (ACE-1) campaign that was conducted above the Southern Ocean. They are present in samples from altitudes as high as 5.4 kin. Morphologically, almost all bacteria are rod-shaped, about 1 mum long or smaller, have one polar flagellum, and contain inclusions that are rich in P and K. Their morphological features suggest that these bacteria are motile, marine species. It seems likely that the cells became airborne by the same bubble-bursting mechanism that ejects sea-salt aerosol particles into the atmosphere;, however, the bacteria and sea-salt particles are typically not aggregated with one another. The estimated number ratio of bacteria and the dominant aerosol species, sea salt, varies in the samples and averages about 1%. The aerosol bacteria seem to represent an important atmospheric reservoir of P and organic compounds; on the other hand, since they are externally mixed with sea salt, they are unlikely to be effective as cloud condensation nuclei.