11:45 AM - 12:00 PM
[AAS04-26] Biogeochemical cycle between atmosphere and ocean via particulate matters
-Award lecture for JpSAC Young Scientist Award-
Keywords:the North Pacific, Mineral dust, Aerosol, Biogeochemical cycles, Cloud condensation nuclei
In my previous work, the sporadic deposition of atmospheric mineral dust by sea fog over the North Pacific was observed during an Asian dust event. By using bulk and individual particle analyses for suspended particulate matters in seawater, the biogeochemical impact of the dust deposition was investigated. As a result, it was found that the bioavailable iron supply to the surface ocean by an Asian dust event was sufficient to promote the growth of phytoplankton, and it also contribute the carbon absorption to the northern North Pacific. In addition, from a mapping data covering the North Pacific and its marginal seas, it was revealed that mineral particles of atmospheric origin existed ubiquitously in the surface ocean even during summer when the influence of Asian dust event is small.
On the other hand, the growth of marine phytoplankton causes changes in the atmospheric environment through aerosol generation. My current research focuses on oceanic aerosols acting as cloud condensation nuclei. From the continuous observation conducted at Noto ground-based research observatory (NOTOGRO) facing the Sea of Japan, it was found that the growth rate of cloud droplets delayed when the organic mass fraction of the aerosol was high. Currently, researches on the linkage between phytoplankton species and marine biogenic aerosol and the climate effect of aerosol generated by bubble bursting at the air-sea interface are conducted.