Sökning: "stratospheric ozone"

Visar resultat 1 - 5 av 28 avhandlingar innehållade orden stratospheric ozone.

  1. 1. Calibration and quality assessment of DESCARTES : grabsampler for stratospheric tracers

    Författare :Johan Arvelius; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Adsorption; Balloon; Carboxen; CFC; Chloro-Fluoro Carbon; Grab sampling; Halocarbon; Molecular sieve; Stratospheric tracer; Tracer; Adsorption; Ballong; Carboxen; CFC; Halogeniserade kolväten; Klor-Flourkarbon; Spårgas; Stratosfärisk spårgas; Space physics; Rymdfysik;

    Sammanfattning : DESCARTES is a light-weight, balloon-borne grab sampler for stratospheric long-lived tracers developed at the University of Cambridge. 33 flights have been performed with two versions of the instrument at northern latitudes by the DESCARTES team at the Swedish Institute of Space Physics (IRF) in Kiruna during the years 1997-2000. LÄS MER

  3. 2. Impact of Rossby waves on ozone distribution and dynamics of the stratosphere and troposphere

    Författare :Grigory Nikulin; Sheila Kirkwood; Ulrike Langematz; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Meteorology; ozone; wave activity; trends; Brewer-Dobson circulation; Rossby waves; Arctic Oscillation; low ozone events; Meteorologi; Meteorology; Meteorologi; Meteorology; meteorologi;

    Sammanfattning : Several physical mechanisms concerning the impact of Rossby waves on ozone distribution and circulation in the stratosphere and troposphere are studied in the thesis.Summertime total ozone variability over Middle Asia and Northern Scandinavia shows similar wave-like behaviour with typical periods of 10-20 days and amplitudes of 20-50 Dobson units. LÄS MER

  4. 3. Validation and time series analysis of global stratospheric data sets

    Författare :Ashley Jones; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; OSIRIS; MIPAS; remote sensing; data assimilation; Trend; stratosphere; ozone; linear regression; Odin; validation;

    Sammanfattning : The depletion of ozone from the stratosphere and the impact of global warming have been identified as phenomena caused as a result of anthropogenic activity. Scientists are thus trying to find quicker and more reliable ways to analyse these environmental problems. LÄS MER

  5. 4. Future stratospheric ozone depletion will affect a subarctic dwarf shrub ecosystem

    Författare :Ulf Johanson; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Vaccinium; UVB; subarctic; shoot growth; ozone depletion; leaf thickness; irradiation system; heath ecosystem; Empetrum; dwarf shrubs; Calamagrostis; decomposition; Physiological biophysics; Växtfysiologi;

    Sammanfattning : The stratospheric ozone depletion and the concomitant increase in ultraviolet-B (UV-B, 280-320 nm) radiation is of global concern due to the effects of UV-B on living organisms. To investigate the effects of increased levels of UV-B, a field irradiation system was established at a subarctic dwarf shrub heath in Northern Sweden (68 °N). LÄS MER

  7. 5. Decadal analysis of stratospheric ozone depletion using data assimilation and Odin/SMR measurements

    Författare :Kazutoshi Sagi; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ozone loss; remote sensing; stratosphere; limb sounding; data assimilation;

    Sammanfattning : Serious ozone depletion has been measured every Antarctic spring since the early 80’s. This ozone depletion is considered to be a result of photo-chemical reactions and catalytic cycles resulting from anthropogenic halogen containing gases. facilitated by the formation of Polar Stratospheric Clouds (PSCs). LÄS MER