| 1. |
- Baker, Alex R., et al.
(författare)
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Changing atmospheric acidity as a modulator of nutrient deposition and ocean biogeochemistry
- 2021
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Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 7:28
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Tidskriftsartikel (refereegranskat)abstract
- Anthropogenic emissions to the atmosphere have increased the flux of nutrients, especially nitrogen, to the ocean, but they have also altered the acidity of aerosol, cloud water, and precipitation over much of the marine atmosphere. For nitrogen, acidity-driven changes in chemical speciation result in altered partitioning between the gas and particulate phases that subsequently affect long-range transport. Other important nutrients, notably iron and phosphorus, are affected, because their soluble fractions increase upon exposure to acidic environments during atmospheric transport. These changes affect the magnitude, distribution, and deposition mode of individual nutrients supplied to the ocean, the extent to which nutrient deposition interacts with the sea surface microlayer during its passage into bulk seawater, and the relative abundances of soluble nutrients in atmospheric deposition. Atmospheric acidity change therefore affects ecosystem composition, in addition to overall marine productivity, and these effects will continue to evolve with changing anthropogenic emissions in the future.
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| 2. |
- Bellerby, Richard, et al.
(författare)
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Acidification in the Arctic Ocean
- 2013
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Ingår i: Chapter 2 in: AMAP, 2013. AMAP Assessment 2013: Arctic Ocean Acidification. Arctic Monitoring and Assessment Programme (AMAP). - Oslo, Norway : AMAP. - 9788279710820 ; , s. 9-36
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Bokkapitel (refereegranskat)abstract
- A consequence of the persistent release of carbon dioxide (CO2) to the atmosphere following fossil fuel combustion and changes in land use is that there is an increasing net air-to-sea transport of CO2. Although this oceanic uptake will reduce the potential for greenhouse warming that would have arisen had the gas remained in the atmosphere, it will also result in major changes in ocean chemistry. The most obvious signal in this respect is the fall in ocean pH and the change in the speciation of the marine carbonate system. The Arctic Ocean is one of the regions where ocean acidification is occurring fastest. From a baseline where the seawater is already poorly buffered and thus small changes in CO2 content have large changes in pH, there are a multitude of stressors that act on the Arctic Ocean amplifying the acidification. This chapter summarizes carbonate chemistry in seawater (Section 2.2) and reviews the major processes influencing the Arctic Ocean carbonate system (Section 2.3). The chapter also describes some of the biogeochemical processes sensitive to ocean acidification (Section 2.4). Section 2.5 addresses the major sources and sinks of carbon to the Arctic Ocean, and presents a regional breakdown of contemporary rates of ocean acidification. Finally, simulations from earth system models and regional models are analyzed to project potential changes to the Arctic Ocean carbonate system (Section 2.6).
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| 3. |
- Gelting, Johan
(författare)
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Speciation of trace metals in the Baltic Sea with focus on the Euphotic zone
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Physicochemical speciation of iron (Fe) and the trace metals Cd, Cu, Co, Mn, Ni, and Zn were performed at four different locations in surface waters of the Baltic Sea. Measurements were performed during several months of the growth season at each station to obtain a detailed picture of the temporal variation in relation to phytoplankton growth. The main target was to understand the speciation of iron, and to evaluate if Fe was limiting in primary production. A methodological aim of the thesis work was focused on comparison between trace metal speciation methods; where the DGT method was calibrated to other methods and also to use the DGT method find out which mechanisms that control the labile fraction. Other methods, such as CSV, CL-FIA and Fe isotope measurements (MC-ICP-MS) were used to further evaluate the changes in the Fe fractions.Concentrations of Mn, Zn and Cd measured by DGT during 2003 and 2004 were similar to concentrations measured in
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