Degree completed in 2017.
The role of windblown dust from ephemeral river valleys in the fertilisation of the Benguela Upwelling System
Andrew Dansie (Dansie) is a Clarendon Scholar undertaking his DPhil at the School of Geography and the Environment. Prior to his DPhil he spent five years as a Research Fellow at the United Nations University, assessing the use of science to effectively manage transboundary freshwater and marine systems. Dansie completed his Masters at the University of Adelaide, where was the Medal recipient for outstanding research, and holds a BSc from Flinders University in South Australia. His current DPhil research investigates the aeolian fertilisation of the marine environment, looking specifically at ephemeral rivers as sources of nutrient-rich mineral aerosols.
Awards and Funding
- Full Clarendon Scholarship (2012-2016), Clarendon Fund - Oxford University Press
- Vice Chancellors Fund (2016), University of Oxford
- Thomas Linacre Studentship (2014), Linacre College, Oxford
- Full special ICAR-8 Student Conference Award (2014), International Society for Aeolian research (ISAR)
- Masters Medal Recipient (2005), University of Adelaide
For his doctoral research, Dansie has conducted a field, laboratory and satellite-based investigation of ocean fertilisation effects from the ephemeral river valleys of Namibia. Working in collaboration with the DO4 Models research project he erected an array of dust and meteorological monitoring equipment along Namibian river valleys. Collected dust samples, dust source-sediments, and surface sediment samples along the entirety of the river systems and their upper catchments were analysed for the important ocean fertilising nutrients; iron, phosphorus and nitrogen. Investigation of the spatial characteristics has shown that ephemeral river geomorphological processes result in highly enriched, and bioavailable, nutrients in the river valley dust. His research has shown that the aeolian contribution of nutrients then produces a direct and significant phytoplanktonic response in one of the global ocean's highest biological primary production regions, the Benguela Upwelling System. His research has shown the Namibian ephemeral river valleys to be a regionally important source of ocean fertilising mineral aerosols and that significant aeolian fertilisation is occurring in the Benguela system. The implications of his research has important implications for small-scale dust sources globally in the need to constrain these numerous and likely highly fertile sources of dust. This is especially so due to changing hydrological flows globally and riverine dust sources expected to increase.
Example of erected monitoring station instrumentation at two monitoring sites in the Tsauchab river valley showing (top) from right to left; BSNEs, DustTrakTM, AWS mast, and vertical flux collectors and (bottom) windblown dust on 19 April 2013.