Sökning: "biogeochemistry"

Visar resultat 6 - 10 av 51 avhandlingar innehållade ordet biogeochemistry.

  1. 6. Modelling the Dissolved Inorganic Carbon System in the Baltic Sea

    Författare :Moa Edman; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Baltic Sea; Kattegat; pH; pCO2; total alkalinity; biogeochemistry; dissolved inorganic carbon; eutrophication; acidification; climate change; numerical modelling;

    Sammanfattning : Oceans are capable of storing part of the emitted anthropogenic carbon dioxide (CO2) due to the formation of carbonic acid and subsequent dissociation. CO2 is also assimilated by biota and the inorganic carbon system is thus coupled to biogeochemical processes. LÄS MER

  3. 7. Determination of mercury chemical speciation in the presence of low molecular mass thiols and its importance for mercury methylation

    Författare :Van Liem-Nguyen; Erik Björn; Ulf Skyllberg; Cynthia Gilmour; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mercury; methylmercury; LMM thiol; mass spectrometry; biogeochemistry; soil; sediment; ICP; WinSGW; modeling; S XANES; ligand exchange; stability constant; boreal wetlands; analytisk kemi; Analytical Chemistry; Environmental Science; miljövetenskap;

    Sammanfattning : Methylmercury (MeHg) is a neurotoxic compound that threatens the well-being of humans and wildlife. It is formed through the methylation of inorganic mercury (HgII) under suboxic/anoxic conditions in soils, sediment and waters. LÄS MER

  4. 8. Geophysical Applications of Vegetation Modeling

    Författare :Jed O Kaplan; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Environmental chemistry; Växtbiokemi; Plant biochemistry; CH4; CO2; stable isotopes; carbon cycle; wetland; ice core; methane; Holocene; mammoths; tundra; ice age; LGM; biogeography; biome; biogeochemistry; Vegetation model; Miljökemi; Physical geography; geomorphology; pedology; cartography; climatology; Fysisk geografi; geomorfologi; marklära; kartografi; klimatologi;

    Sammanfattning : This thesis describes the development and selected applications of a global vegetation model, BIOME4. The model is applied to problems in high-latitude vegetation distribution and climate, trace gas production, and isotope biogeochemistry. LÄS MER

  5. 9. The geochemistry of two selected areas of the deep sea, the TAG hydrothermal mound, Mid-Atlantic Ridge and the Lomonosov Ridge, central Arctic Ocean

    Författare :Hakam Al-Hanbali; Gustaf Arrhenius; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biogeochemistry; biogeokemi;

    Sammanfattning : .... LÄS MER

  7. 10. Hydrothermal alteration of organic matter at spreading centers

    Författare :Eva Andersson; Bernd R.T. Simoneit; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemistry; Kemi; Biogeochemistry; biogeokemi;

    Sammanfattning : Alteration of organic matter, mainly amino acids, at sub-seafloor hydrothermal conditions has been investigated by performing laboratory experiments and by studying deep-sea sediments from hydrothermally active areas on the northern Juan de Fuca Ridge, northeast Pacific Ocean.Quaternary sediments from Middle Valley and the eastern flank of the Juan de Fuca Ridge recovered during the Ocean Drilling Program Legs 139 and 168 have been analyzed for total hydrolyzable amino acid concentrations, individual amino acid abundances and stereochemistry in order to evaluate the effects of hydrothermal stress on the decomposition of sedimentary amino acids. LÄS MER