Sökning: "Carbon fluxes"

Visar resultat 6 - 10 av 172 avhandlingar innehållade orden Carbon fluxes.

1. 6. Lake Fluxes of Methane and Carbon Dioxide

   Författare :Eva Podgrajsek; Erik Sahlée; Dennis Baldocchi; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; air-lake gas exchange; carbon dioxide; eddy covariance; floating chambers; methane; waterside convection; Meteorology; Meteorologi;

   Sammanfattning : Methane (CH4) and carbon dioxide (CO2) are two important greenhouse gases. Recent studies have shown that lakes, although they cover a small area of the globe, can be very important natural sources of atmospheric CH4 and CO2. LÄS MER

3. 7. Land-atmosphere exchange of carbon in a high-Arctic wet tundra ecosystem

   Författare :Torbern Tagesson; BECC: Biodiversity and Ecosystem services in a Changing Climate; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; carbon; methane; carbon dioxide; climate change; Arctic; NDVI; NDWI; micrometeorology; remote sensing; chamber; tundra;

   Sammanfattning : Arctic ecosystems play a key role in the terrestrial carbon (C) cycle, but spa-tially explicit data on the C exchange is scarce in these remote areas. The global warming is especially dominant in the Arctic, and these areas are vul-nerable to climate change. LÄS MER

4. 8. Production and emission of CO2 in two unproductive lakes in northern Sweden

   Författare :Jan Åberg; Mats Jansson; Anders Jonsson; David Bastviken; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; lake; carbon dioxide; organic carbon; inorganic carbon; boreal; arctic; DOC; DIC; CO2; emission; thermal stratification; allochthonous organic carbon; Freshwater ecology; Limnisk ekologi; Physical geography; Naturgeografi; naturgeografi; Physical Geography;

   Sammanfattning : Unproductive lakes are one of few natural landscape compartments with net release of carbon to the atmosphere. Lakes also generally decrease the net terrestrial carbon uptake, since most of the CO2 production in unproductive lakes are derived from organic carbon produced on land (e.g. in forests). LÄS MER

5. 9. Fluxes and transformation of carbon in the Siberian shelf seas under changing environment

   Författare :Irene Wåhlström; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Carbon system; Carbon dioxide; Arctic Ocean; Siberian shelf seas; Climate change;

   Sammanfattning : The Arctic is especially vulnerable to the increased air temperature caused by emissions of greenhouse gases to the atmosphere, carbon dioxide being one of them. In this thesis, both fieldwork and modelling of the East Siberian Arctic Shelf (the Laptev Sea and the East Siberian Sea) have been carried out to investigate the carbon system in this region. LÄS MER

7. 10. Free-Vehicle Benthic Lander Technology for the Study of Biogeochemical Processes in Marine Sediments

   Författare :Anders Tengberg; Göteborgs universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; marine sediments; benthic fluxes; incubations; chambers; in-situ; benthic landers; autonomous vehicles; lander technology; hydrodynamics; calibration; experimental design; Partial Least Squares PLS ; sensors; fugacity; oxygen; carbon; nitrogen; phosphorus; silica; dissolved organic carbon DOC ; total carbonate; recycling; burial; lander technology;

   Sammanfattning : Various sediment sampling and incubation techniques were used to characterize benthic biogeochemical processes important for an improved understanding of the oceanic carbon cycle. Recent flux data from the Arctic Siberian shelf are revealing differences (often by a factor of ten) between areas affected by the big Russian river outlets (high fluxes) and areas with low influence from land (low fluxes). LÄS MER