Impact of climate change on carbon export at high and low latitudes
The overarching objective of my PhD project is to better understand the processes that control the production, export, and transformation of organic matter in the ocean under changing climate conditions at high and low latitudes.
One region that is especially vulnerable to climate warming is the Arctic Ocean, where changes in sea ice thickness and extent also affect biological and biogeochemical processes. For our understanding of the biological carbon pump at high latitudes and the prediction of future carbon storage it is therefore essential to understand the role of changing sea ice conditions on productivity, community composition, trophic interactions, remineralization, and the export of carbon. By relating the export flux and particle composition to the prevailing plankton communities, the environmental pelagic and sea ice conditions, and the vertical distribution of aggregates and zooplankton, we want to contribute to a better understanding of the role that different ice regimes might have on particulate organic carbon fluxes in a warming Arctic.
A second key region for gaining a better understanding of processes that control the production, export, and transformation of organic matter in a warming ocean is the (tropical) Atlantic Ocean west of Africa. The effect of desert dust deposition on the biological carbon pump in lower latitudes and thus the sequestration of carbon in the ocean is most likely enormous, especially in the context of a decrease in phytoplankton productivity due to a warming-driven increase in thermal stratification and reduced nutrient availability. To better understand the relationship between dust deposition, phytoplankton response and particle/downward carbon export will therefore be a second focus of my PhD project.
