Climate - Biogeochemistry Interactions in the Tropical Ocean

Climate - Biogeochemistry Interactions in the Tropical Ocean
General information
The distribution of oxygen in the ocean interior is controlled by an intimate interplay of physics and biology. Circulation and mixing transport oxygen into the ocean interior from the near-surface where it is produced by photosynthesis and exchanged with the atmosphere. Oxygen consumption occurs throughout the ocean and is essentially driven by bacterial respiration of organic matter. Both the supply and consumption of oxygen are sensitive to climate change in ways that are not fully understood. When oceanic oxygen concentrations decrease below certain threshold levels, major changes to remineralisation processes and associated marine sources and sinks of important nutrient elements such as nitrogen, phosphorus and iron can occur in the water column and underlying sediments. Low oxygen levels can therefore be viewed as a “switch” for nutrient cycling.The tropical Oxygen Minimum Zones (OMZs) are the key regions of low oxygen in today’s ocean. The effects of oxygen-dependent nutrient cycling processes occurring in these relatively small regions are carried into the rest of the ocean by the circulation. Hence “small” OMZs can impact nutrient budgets, biological productivity and CO2-fixation of the global ocean. SFB 754 addresses the relatively newly recognized threat of ocean deoxygenation, its possible impact on tropical oxygen minimum zones and implications for the global climate-biogeochemistry system. The overall goal is to improve the understanding of the coupling of tropical climate variability and circulation with the ocean’s oxygen and nutrient balance, to quantitatively evaluate the nature of oxygen switches in marine nutrient cycles, as well as to assess consequences for the Ocean’s future.
Start January, 2008 End December, 2019
Funding (total) 10,161 T€ Funding (GEOMAR) 10,161 T€
Funding body DFG-SFB Programme SFB
Contact Andreas Oschlies
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