Sökning: "Frozen soil"

Visar resultat 6 - 10 av 27 avhandlingar innehållade orden Frozen soil.

1. 6. Land surface heat exchange over snow and frozen soil

   Författare :David Gustafsson; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Surface energy balance; Snow; Boreal forest; SVAT models; Eddy-correlation Measurements; Latent heat flux; Sensible heat flux; Net radiation; Soil temperature; Aerodynamic roughness; Surface resistance; Civil engineering and architecture; Samhällsbyggnadsteknik och arkitektur;

   Sammanfattning : The energy exchange in the soil-snow-vegetation-atmospheresystem was studied to improve the quantitative knowledge of thegoverning processes. The lack of such knowledge contributes tothe uncertainty in the applicability of many existing modelsindependent of the temporal or spatial scale. LÄS MER

3. 7. Microbial life in boreal soils : on the availability and fate of carbon substrates for microbial activity in boreal soils

   Författare :Javier Segura; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
   Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

   Sammanfattning : The large pool of carbon (C) stored as soil organic matter (SOM) in soils of high-latitude ecosystems contains more organic C than all global vegetation and the atmosphere combined. Global climate change is expected to have especially pronounced effects in these ecosystems, and even small changes in the accumulation and decomposition of their soil C pool driven by heterotrophic microbial activity could profoundly affect atmospheric CO₂ levels and thus the global climate. LÄS MER

4. 8. Soil organic carbon in permafrost terrain : Total storage, landscape distribution and environmental controls

   Författare :Gustaf Hugelius; Peter Kuhry; Jan Boelhouwers; Stockholms universitet; []
   Nyckelord :;

   Sammanfattning : High latitude terrestrial ecosystems are considered key components in the global carbon (C) cycle and hold large reservoirs of soil organic carbon (SOC). To a large degree, this SOC is stored in permafrost soils and peatlands and is vulnerable to remobilization under future global warming and permafrost thawing. LÄS MER

5. 9. Use of thermosyphons in a subarctic climate

   Författare :Anna Forsström; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Soil Mechanics; Geoteknik;

   Sammanfattning : In frozen ground, climatic changes and thermal disturbance might cause thawing and degradation of ground previously frozen. Foundations built on frozen ground might be destroyed in a matter of a few seasons. These problems are mostly pronounced in permafrost regions, but also exist in regions with more moderate climates. LÄS MER

7. 10. Modeling of frost heave and surface temperatures in roads

   Författare :Åke Hermansson; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Soil Mechanics; Geoteknik;

   Sammanfattning : Temperature and moisture are very essential parameters when describing the condition of a pavement. In most cases, a high moisture content involves a decreased bearing capacity and, consequently, a shorter durability of the pavement. A frozen pavement has a greater bearing capacity than the corresponding construction in spring or late autumn. LÄS MER