Avancerad sökning

Visar resultat 1 - 5 av 231 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Experimental investigation of snow metamorphism at near-surface layers

   Författare :Lavan Kumar Eppanapelli; Mikael Sjödahl; Johan Casselgren; Arne Instanes; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Snow metamorphism; NIR reflectance; Snow and Ice; Radiative transfer equation; Paramterization; Snow properties; Tomography; Snow microstructure; Experimentell mekanik; Experimental Mechanics;

   Sammanfattning : Snow metamorphism is a direct objective in many snow research areas, and its charac-terisation is a major challenge in areas including winter road maintenance, detection of icing on wind turbine blades, and snow quality mapping for skiing. A common effect of snow metamorphism is compaction, which can be investigated from the associated vari-ations in physical properties of snow. LÄS MER

3. 2. Snow particle size investigations using digital image analysis - implications for ground observations and remote sensing of snow

   Författare :Susanne Ingvander; Peter Peter Jansson; Matti Matti Leppäranta; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; snow; remote sensing; particle size; Antarctica; in-situ sampling; seasonal snow; Physical Geography; naturgeografi;

   Sammanfattning : During the past century climate warming has caused rapid changes in the Cryosphere. This has increased the need to accurately monitor rates of change in snow and ice in remote or sparsely populated areas where environmental observing capacity is limited. Monitoring snow cover requires understanding of the snow pack and the snow surface attributes. LÄS MER

4. 3. Boreal land surface water and heat balance : Modelling soil-snow-vegetation-atmosphere behaviour

   Författare :David Gustafsson; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; soil; snow; land surface heat exchange; forest; arable land; eddy-correlation; Civil engineering and architecture; Samhällsbyggnadsteknik och arkitektur;

   Sammanfattning : The water and heat exchange in thesoil-snow-vegetation-atmosphere system was studied in order toimprove the quantitative knowledge of land surface processes.In this study, numerical simulation models and availabledatasets representing arable land, sub-alpine snowpack, andboreal forest were evaluated at both diurnal and seasonaltimescales. LÄS MER

5. 4. Sustainable snow handling

   Författare :Karin Reinosdotter; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; VA-teknik; Urban Water Engineering;

   Sammanfattning : Urban snow contains pollution that originates from sources such as atmospheric precipitation, traffic emission, and de-icing chemicals. These pollutants accumulate in the snow during the winter and are released when the snow starts to melt. LÄS MER

7. 5. 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