Sökning: "natural circulation"

Visar resultat 6 - 10 av 232 avhandlingar innehållade orden natural circulation.

1. 6. Holocene climate and atmospheric circulation changes in northern Fennoscandia : Interpretations from lacustrine oxygen isotope records

   Författare :Christina E. Jonsson; Gunhild Rosqvist; Jan Seibert; Philip Barker; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; oxygen isotope; diatom silica; lake sediment; atmospheric circulation; North Atlantic Oscillation; northern Fennoscandia; The Holocene; Little Ice Age; Physical geography; Naturgeografi; Physical Geography; naturgeografi;

   Sammanfattning : This thesis investigates how variations in the oxygen isotopic composition of lake waters in northern Fennoscandia are recorded in lake sediment archives, especially diatoms, and how these variations can be used to infer past changes in climate and atmospheric circulation. Results from analyses of the oxygen isotopic composition of lake water samples (δ18Olakew) collected between 2001 and 2006 show that δ18O of northern Fennoscandian lakes is mainly controlled by the isotopic composition of the precipitation (δ18Op). LÄS MER

3. 7. Iodine Isotopes (129I and 127I) in the Baltic Sea   : Tracer applications & environmental impact

   Författare :Peng Yi; Ala Aldahan; Glen Snyder; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; radioactive 129I; stable 127I; AMS; iodine species; nuclear reprocessing facilities; tracers; Baltic Sea; circulation; water exchange; environmental impact;

   Sammanfattning : 129I is a radioactive isotope (T1/2= 15.7 million years) produced through natural and anthropogenic pathways, but the anthropogenic production is presently dominating the Earth’s surface environments. LÄS MER

4. 8. Cardiovascular and respiratory effects of apnea in humans

   Författare :Johan Andersson; Funktionell zoologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; lung volume; breath-hold diving; Apnea; breath-holding; face immersion; cold stimulation; diving response; diving reflex; circulation; bradycardia; vasoconstriction; arterial blood pressure; cardiac output; spleen; respiration; splenic contraction; alveol; Physiology; Fysiologi; Respiratory system; Andningsorganen; Animal physiology; Djurfysiologi;

   Sammanfattning : This thesis deals with cardiovascular and respiratory effects of apneas in humans. During apnea (breath-holding), a number of interacting cardiovascular reflexes are initiated, and together these reflexes are called the “diving response”. LÄS MER

5. 9. Spatiotemporal climate and atmospheric circulation variability in Asia inferred from tree rings

   Författare :Andrea Seim; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Asia; atmospheric circulation; Central Asia; dendroclimatology; growth-climate relationship; objectively classified weather types; teleconnections; tree-ring networks;

   Sammanfattning : Observed 20th century warming trends accompanied by more frequent weather extremes such as droughts or intense rainfall events have consequences for societies and environments alike. In Asia, where the majority of the population depend on agricultural productivity, recent climate change is likely to increase societal hardships. LÄS MER

7. 10. Relationships between Atmospheric Circulation and Wind Erosion in Southern Sweden and Australia

   Författare :Marie Ekström; Institutionen för naturgeografi och ekosystemvetenskap; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; pedology; cartography; climatology; Fysisk geografi; geomorfologi; marklära; kartografi; klimatologi; Physical geography; geomorphology; Geologi; fysisk geografi; physical geography; Geology; sea level pressure; atmospheric circulation; erosivity; wind erosion; wind climatology; Scania; Australia;

   Sammanfattning : Wind erosion is a serious threat to soil resources as it causes depletion of the fine fractions that may result in a less fertile soil. Wind erosion encompasses several processes of which many are related to climate variables. To date, there is little work performed on how wind erosion relates to climate and climate change. LÄS MER