Sökning: "High- altitude"

Visar resultat 6 - 10 av 97 avhandlingar innehållade orden High- altitude.

  1. 6. High altitude ion heating observed by the Cluster spacecraft

    Författare :Martin Waara; Hans Nilsson; Kristina Lynch; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Space physics; Rymdfysik; rymd- och plasmafysik; Space and Plasma Physics;

    Sammanfattning : This thesis deals with heating of outowing oxygen ions at high altitude above the polar cap using data from the Cluster spacecraft. oInospheric plasma may flow up from the ionosphere but at velocities which are low enough that the ions are still gravitationally bound. For the ions to overcome gravity, further acceleration is needed. LÄS MER

  3. 7. Karaktäristiken hos strukturmarken på olika altitud i Abiskoområdet – en koppling till klimat och komplex systemteori

    Författare :Gunnar Scharin; Christer Jonasson; Johan Kling; Uppsala universitet; []
    Nyckelord :Abisko; patterned ground; permafrost; non-sorted circles; altitude; self-generation; Geovetenskap med inriktning mot miljöanalys; Earth Science with specialization in Environmental Analysis; Earth Science with specialization in Physical Geography; Geovetenskap med inriktning mot naturgeografi; Biology with specialization in Ecological Botany; Biologi med inriktning mot ekologisk botanik;

    Sammanfattning : Subarctic and alpine areas are sensitive to climatic change when they lie at the margin of permafrost occurrence. Patterned ground in such areas is generated from an interplay among different mechanisms such as temperature, hydrology, soil texture, snow cower and vegetation. LÄS MER

  4. 8. Initiation of spleen contraction resulting in natural blood boosting in humans

    Författare :Angelica Lodin; Erika Schagatay; Mats H. Linér; Mittuniversitetet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Acclimatization; altitude; apnea; breath-hold diving; hemoglobin; hypercapnia; hypoxia; triggers;

    Sammanfattning : The spleen has been shown to contract in apneic situations in humans as well as in other diving mammals, expelling its stored red blood cell content into circulation. This natural blood boosting may increase the circulating hemoglobin concentration (Hb) by up to 10%, which would enhance the oxygen carrying capacity and likely increase performance. LÄS MER

  5. 9. Biodiversity patterns and the processes regulating them along elevation gradients in the Swedish mountains

    Författare :Johannes Måsviken; Love Dalén; Anne Bjorkman; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; biodiversity; elevation gradients; spiders; insects; plants; latitude; altitude; alpha diversity; beta diversity; taxonomic diversity; phylogenetic diversity; functional diversity; Systematic Zoology; zoologisk systematik och evolutionsforskning;

    Sammanfattning : Biodiversity describes the total variation of life and includes the taxonomic, genetic, and phenotypic differences among organisms. Variations of biodiversity in space and time may be driven by ecological, evolutionary, or neutral processes. LÄS MER

  7. 10. The role of herbivores in mediating responses of tundra ecosystems to climate change

    Författare :Elina Kaarlejärvi; Johan Olofsson; Anu Eskelinen; Jon Moen; Eric Post; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Climate change; warming; grazer; Rangifer; Lemmus lemmus; species distribution; biotic interactions; altitude; Environmental Science; miljövetenskap;

    Sammanfattning : The Arctic areas are warming more rapidly than other parts of the world. Increasing temperatures are predicted to result in shrubification, higher productivity, declining species diversity and new species invasions to the tundra. LÄS MER