Sökning: "open ocean"
Visar resultat 1 - 5 av 43 avhandlingar innehållade orden open ocean.
1. Significance of N2 fixing planktonic symbioses for open ocean ecosystems
Sammanfattning : Di-nitrogen (N2) fixers, also called diazotrophs, are able to reduce atmospheric N2 into bioavailable nitrogen, giving them an advantage in open ocean regions with low dissolved inorganic nitrogen concentrations. The focus of this thesis are three lineages of symbiotic heterocystous filamentous types (het-1, het-2 and het-3), that associate with several genera of microalgae called diatoms (collectively referred to as Diatom Diazotroph Associations, DDAs). LÄS MER
2. Digital technologies as support for learning about the marine environment: Steps toward ocean literacy : Digital technologies and ocean literacy
Sammanfattning : Over the last century the ocean has been negatively impacted by human activities. In order to continue benefitting from marine services and goods, and the qualities afforded to human life through the ocean, citizens need to be informed about their relationship to the ocean and their own impact on it, that is they need to be ocean literate. LÄS MER
3. Anthropogenic Radionuclides in the Arctic Ocean: Distribution and Pathways
Sammanfattning : Anthropogenic radionuclide concentrations have been determined in seawater and sediment samples collected in 1991, 1994 and 1996 in the Eurasian Arctic shelf and interior. Global fallout, releases from European reprocessing plants and the Chernobyl accident are identified as the three main sources. LÄS MER
4. Applications of ocean transport modelling
Sammanfattning : The advective motion of seawater governs the transport of almost everything, animate or inanimate, present in the ocean and those lacking the ability to outswim the currents have to follow the flow. This makes modelling of advective ocean transports a powerful tool in various fields of science where a displacement of something over time is studied. LÄS MER
5. 231Pa, 230Th and 232Th as tracers of deep water circulation and particle transport : Insights from the Mediterranean Sea and the Arctic Ocean
Sammanfattning : The naturally occurring U and Th-series radionuclides have shown to have a considerable importance for the understanding of biogeochemical processes on Earth and in the ocean. In this thesis, the isotopes 230-thorium (230Th), 232-thorium (232Th) and 231-protactinium (231Pa) are used as tracers of the transport and scavenging of marine particles and water circulation. LÄS MER