The ocean interacts with the atmosphere and lithosphere through continuous exchange of matter and energy. Understanding exchange processes across the ocean interfaces is key to unraveling complex interplays such as climate system feedbacks. The relevant processes are determined by a combination of physical, chemical, and biological processes acting on a variety of scales in time and space. Accumulation of organic and inorganic substances, both in the wider boundary layers and in the microlayers directly at the interface, together with intense biological activity, lead to unique heterogeneous physico-chemical and biological properties deviating greatly from bulk seawater conditions. Further modifications of ocean interfaces, e.g., through photochemical and microbial transformations, contribute to forming an environment, in which transfer processes can both be augmented and diminished.
The Research combines state-of-the-art molecular, microbiological and biogeochemical analytical techniques, laser spectroscopy, micro and mesocosm experimentation, in-situ measurements and theoretical modeling. Three research foci of Ocean Interfaces have been set to advance from the at present mostly phenomenological description to a mechanistically sound parameterization of interfacial exchange processes and to improve our process-oriented understanding of selected climate feedback cycles:
Focus 1 investigates formation, retention and emission processes of climate-relevant substances
Focus 2 links biological imprints on extracellular organic matter to interface properties by investigating the accumulation of organic substances and their intense microbial transformation in the surface ocean boundary layer.
Focus 3 investigates (i) chemical aspects of the ocean as a major source and sink for radiatively and chemically active atmospheric trace gases and (ii) the specific roles of the prevalent organic microlayer in sea-air gas exchange processes and as a biochemical reactor.