Sökning: "atmospheric chemistry"

Visar resultat 21 - 25 av 144 avhandlingar innehållade orden atmospheric chemistry.

  1. 21. Satellite Limb-Scatter Observations of Stratospheric NO2 and O3 -Retrievals, Validation and Applications

    Författare :Samuel Brohede; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; satellite; NO2; Odin; limb-scatter; validation; OSIRIS; stratosphere; remote sensing; O3; retrieval;

    Sammanfattning : Global observations of vertically resolved atmospheric constituents with high temporal and spatial sampling are crucial for various scientific assessments of ozone depletion and climate change. This thesis explains how such data can be retrieved from satellite limb-scatter observations. LÄS MER

  3. 22. Optical remote sensing of industrial gas emission fluxes

    Författare :John Johansson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; DOAS; formaldehyde; optical remote sensing; gas emission; absorption spectroscopy; solar occultation; VOC; flux measurement; FTIR;

    Sammanfattning : Mobile optical remote sensing techniques offer promising possibilities to quantify and geographically attribute local industrial gaseous emissions to the atmosphere. Studies have shown that such emissions are often poorly understood, underestimated, and thereby not properly accounted for in emission inventories and regional atmospheric chemistry models, especially for emissions of VOCs. LÄS MER

  4. 23. Mercury cycling in the global marine environment

    Författare :Michelle Nerentorp; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; sea ice; air; seasonal and spatial variation; snow; Mercury cycling; seawater; mercury flux;

    Sammanfattning : Mercury is a globally distributed contaminant that exists in the atmosphere in its elemental form as a stable monoatomic gas. Having a residence time of around one year in air allows it to be transported far from emission sources and end up in polar ecosystems. LÄS MER

  5. 24. Transport and chemical processing of trace gases in deep convective clouds

    Författare :Roman Bardakov; Annica M. L. Ekman; Mary C. Barth; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; gas transport; atmospheric chemistry; convective cloud; box model; new particle formation; atmosfärvetenskap och oceanografi; Atmospheric Sciences and Oceanography;

    Sammanfattning : Deep convective clouds can efficiently transport trace gases from the planetary boundary layer to the upper troposphere. Once there, some gases will contribute to new particle formation and growth, eventually producing aerosols that are large enough to influence cloud properties, the radiative budget of the Earth, and climate. LÄS MER

  7. 25. Atmospheric pressure ionisation interface considerations for micro column separation with mass spectrometric detection

    Författare :Per J. R. Sjöberg; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemistry; Kemi; Chemistry; Kemi; Analytical Chemistry; analytisk kemi;

    Sammanfattning : Two miniaturised atmospheric pressure chemical ionisation (APCI) interfaces were developed for micro column separation and their performances were investigated in high temperature open tubular column liquid chromatography and capillary supercritical fluid chromatography (SFC). The most influential parameters, for example, the interface probe position relative to the sampling orifice and the reagent ion plasma composition, were investigated to optimise the ion current signal and stability. LÄS MER