Japan Geoscience Union Meeting 2025

Presentation information

[J] Oral

A (Atmospheric and Hydrospheric Sciences ) » A-CG Complex & General

[A-CG50] Biogeochemical linkages between the surface ocean and atmosphere

Thu. May 29, 2025 3:30 PM - 5:00 PM Exhibition Hall Special Setting (6) (Exhibition Hall 7&8, Makuhari Messe)

convener:Sohiko Kameyama(Hokkaido University), Yoko Iwamoto(Graduate School of Integrated Sciences for Life, Hiroshima University), Maki Noguchi Aita(Japan Agency for Marine-Earth Science and Technology), Naohiro Kosugi(Meteorological Research Institute), Chairperson:Naohiro Kosugi(Meteorological Research Institute), Maki Noguchi Aita(Japan Agency for Marine-Earth Science and Technology)

3:30 PM - 4:00 PM

[ACG50-06] Research on biogeochemical processes at sea surface microlayer

★Invited Papers

*Yumiko Obayashi1 (1.Ehime University)

Keywords:Sea surface microlayer, Microbial community, Hydrolytic activity

At the sea surface, the interface between the liquid (seawater) and the gas (atmosphere), surfactants and substances with lower density than seawater might accumulate. In fact, it has been reported that higher concentration of some kinds of organic matter and microorganisms in the sea surface microlayer than in the underlying seawater
Bubbles in seawater rise to the surface and burst at the sea surface while scavenging for surfactants and fine particles in the seawater. The fine particles generated during this process become oceanic aerosols (sea spray aerosols), and substances on the bubble walls and in the sea surface microlayer are incorporated into these aerosols. Therefore, the investigation of biological and chemical characteristics of the sea surface microlayer, such as the composition of organic matter, microbial communities, and microbial activity, will provide important information on the characteristics of sea spray aerosols, and insights to their climate effects.
One of the parameters relevant to biogeochemical processes in marine ecosystems is the activity of hydrolytic enzymes in seawater, which are microbial extracellular hydrolases. The hydrolytic activity detected in seawater indicate microbial metabolic activity and their characteristics in marine ecosystems.
This talk will present observational results of hydrolytic activity in the sea surface microlayer, and discuss microbial activities and biogeochemical processes at the ocean-atmosphere boundary.