Research interests:
Distribution of trace elements in the ocean
Geochemical behaviour of High field strength elements (HFSE) Zr, Nb, Hf, Ta and W in different regions of the world Ocean
Influence of regional features, e.g. anthropogenic input, hydrothermal input, oxygen minimum zone, dust input, on HFSE distribution in Oceans
Research project: Sinks, sources and processes of selected transition metals in the ocean – a contribution to the GEOTRACES program
A variety of trace elements that are contained in the water of the oceans can give us a lot of information about the ocean`s state in the present and past. Studying their distribution in water masses is important for learning about biogeochemical processes and global ocean circulation.
Even today distributions and geochemical behaviour of some trace metals are poorly understood, especially for those metals that due to very low natural concentrations are difficult to analyse. My research work during my PhD will contribute to closing this knowledge gap and is embedded in the international GEOTRACES program.
My research will focus on the geochemical behaviour of so-called high field-strength elements (HFSE, e. g. Zr, Nb, Hf, Ta) and W in different regions of the world Ocean and the influence of regional features (e.g. anthropogenic input, hydrothermal input, oxygen minimum, dust input). These HFSE are known as paleoproxy for water masses. The concentrations of these elements will be measured with ICP-MS, however, as the concentrations of these elements in the seawater samples are extremely low (pmol kg−1) the samples will be pre-concentrated by an offline-seaFAST system.
Another question to consider is how HFSE are represented in different size fractions (dissolved – colloidal – particulate) in the samples and the influence of fractionization of these elements on their transport and flux in oceans. To investigate this, ultrafiltration and sequential filtration samples from the same stations will be analyzed and the distribution of the trace metals in the different trace fractions as well as changes as responses to environmental changes will be compared.
For the different partial projects of the thesis, samples from different ocean regions with different conditions (sinks, sources, and environmental parameters) will be analyzed and compared. The study area includes the North Sea (cruise M169), the Tropical Atlantic Ocean including Rainbow vent field (cruise M176/2), the South Pacific Ocean (cruise SO289), and the Central Pacific Ocean (upcoming cruise SO298). While the first three regions were sampled by the geochemistry team of Jacobs University in the past few years, I will participate in cruise SO298 in April/May 2023 and take the last set of samples on my own. Except cruise M169, all cruises were acknowledged GEOTRACES cruises, and all samples were taken under trace-metal clean conditions. With my work, I will provide a significant contribution to the GEOTRACES mission to identify processes and quantify fluxes that control the distributions of key trace elements and isotopes in the ocean, and to establish the sensitivity of these distributions to changing environmental conditions.