Search for dissertations about: "Stratospheric tracer"

Found 5 swedish dissertations containing the words Stratospheric tracer.

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

   Author : Johan Arvelius; Umeå universitet; []
   Keywords : 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;

   Abstract : 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. READ MORE

4. 2. Application of Infrared and UV-Visible Remote Sensing Techniques for Studying the Stratosphere and for Estimating Antrophogenic Emissions

   Author : Johan Mellqvist; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; stratospheric ozone; temperature dependence; non linearity; FTIR; VOC; flue gas; DOAS; long path FTIR; fugitive emissions;

   Abstract : Infrared and UV/visible broadband absorption techniques have been used in three applications related to environmental research and atmospheric science. The techniques are based on measuring the attenuation of light by the atmosphere in the infrared and UV/visible region, and since a very large number of species absorb light in these wavelength regions, the techniques studied allow the measurement of several species simultaneously. READ MORE

5. 3. On Numerical Tracer Advection in the Stratosphere and Assimilation of Data from Satellites

   Author : JOHN RÖSEVALL; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; stratosphere; transport modelling; O3; ozone depletion; data assimilation;

   Abstract : Since the early 1980's, large scale ozone depletion has been observed in the lower regions of the ozone layer over Antarctica when sunlight returns to the polar region in the early spring. The destruction of ozone is attributed to anthropogenic emissions of freon and halon compounds that have augmented the natural stratospheric concentrations of nonreactive Clx and Brx reservoir species with several hundred percent. READ MORE

6. 4. Development and Application of Methods based on DOAS and FTIR Absorption Spectroscopy for Atmospheric Research

   Author : Bo Galle; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; open-path; nitrous oxide; DOAS; long-path absorption; landfill; methane; climate gases; ozone depletion; biogenic emissions; fugitive emissions; FTIR; ammonia;

   Abstract : Over the past decades concern about the environmental impact on our atmosphere from human activities has been constantly increasing. From the recognition of local industrial pollution in the first part of this century, over regional scale problems related to urbanisation and growth of traffic systems to global environmental problems such as climate change and stratospheric ozone depletion. READ MORE

7. 5. Meteoric Aerosols in the Middle Atmosphere

   Author : Linda Megner; Jörg Gumbel; Martin Ridal; Gary E. Thomas; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; meteoroid; meteor; nucleation; mesosphere; stratosphere; ablation; smoke; NLC; PMSE; PSC; Atmosphere and hydrosphere sciences; Atmosfärs- och hydrosfärsvetenskap; atmosfärvetenskap; Atmospheric Sciences;

   Abstract : This thesis concerns the fate of the meteoric smoke in the Middle Atmosphere, and its effect on ice phenomena such as noctilucent clouds (NLC) and polar stratospheric clouds (PSC). The potential role of NLC as tracer for mesospheric processes and variability, and as a tool for monitoring this remote and inaccessible region, has generated substantial interest within the scientific community. READ MORE