Drs. A. W. (Anne Willem) Omta

Room: T543
Phone: 020-5986959
Email: anne.willem.omta@falw.vu.nl
C. Vitae:
Project: Organic carbon pump in meso-scale ocean flows

Organic carbon pump in meso-scale ocean flows

Global warming might have serious ecological, economical, and political consequences in the near future. Therefore it is of vital importance to the world community to obtain reliable estimates of the rate at which carbon dioxide will accumulate in the atmosphere, since carbon dioxide is after water the main greenhouse gas. Unfortunately, there is still controversy about which processes are mainly responsible for the removal of carbon from the atmosphere, and the mechanisms behind these processes are in many cases poorly understood. Carbon dioxide uptake by biota occurs in the ocean and terrestrial environments; weathering of siliceous rocks also removes carbon from the atmosphere. However, organic matter on land is oxidized prior to incorporation into soils, and therefore marine processes are probably more important for the global carbon budget than processes on land. One marine process that is probably responsible for the removal of a large portion of the emitted carbon dioxide is the so-called Organic Carbon Pump. Algae bind carbon dioxide from the atmosphere to build biomass. This biomass eventually sinks into the deep ocean as POM (Particulate Organic Matter) where it is partly buried into sediments. For the efficiency of the Organic Carbon Pump (vertical) transport of nutrients and the algae themselves by flows in the ocean is very important. In the oceans, there are many mesoscale eddies and rings (diameters of about 100 km) 'stirring' the ocean, probably influencing the concentration of organic carbon. Hence, the aim of this project is to investigate and quantify the influence of mesoscale structures in the ocean on the efficiency of the Organic Carbon Pump.

Methods and research plans

We make use of a nonhydrostatic flow model to simulate the mesoscale flow structures coupled to a biological Dynamic Energy Budget model to simulate the resulting plankton growth. There is a close collaboration with Jorn Bruggeman for the implementation of the biology and with the CWI (Centrum voor Wiskunde en Informatica) for numerical methods to simulate at a higher resolution. We will start by simulating an idealised ring or eddy. If we understand the behaviour of this idealised structure, we will extend the model to more realistic structures and even whole basins. Finally we will try to apply the model to other kinds of studies such as reconstructions of productivity in the geologic past.

Anne Willem acquired the prestigious Rubicon grant from the National Science Foundation (NWO) for his postdoc work at MIT, US. He defended his thesis at 2009/03/06 in Amsterdam.

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