300329 VO Biogeochemistry of the Ocean (2020W)

Biogeochemistry of the oceans is the study of biological, geological, physical and chemical processes that govern the distribution of chemical elements in the ocean. On a short time scale the cycling of elements in the ocean (such as carbon, nitrogen and phosphorus) is generally influenced by biological processes. To predict the matter cycling processes on longer time scales (>10 years), however, it is necessary to infer the biological processes from chemical measurements based on the knowledge of water transport in the ocean. The fate of anthropogenic CO2 added to the atmosphere is one topic where the interdisciplinary field of biogeochemistry leads to major insights on the feedback mechanisms of the ocean and its long term balancing effect on global change.
The lecture starts with describing the distribution of the major chemical elements in the ocean followed by an introduction to the mechanisms of the water mass transport through the oceans. Exchange processes between the air-sea interface and between the ocean and the seafloor sediments will inform us about the boundary conditions of the cycling of matter in the ocean. Based on this knowledge we will develop the cycles of Nitrate, Phosphate, Silicate, Carbon and Calcium Carbonate in the open ocean that will point out the link between the different disciplines of bio-geo-chemistry.