Sökning: "middle atmospheric dynamics"

Visar resultat 6 - 10 av 13 avhandlingar innehållade orden middle atmospheric dynamics.

  1. 6. The impact of mesospheric dynamics and chemistry on key chemical species: 20 years of Odin/SMR satellite observations

    Författare :Francesco Grieco; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; mesosphere; energetic particle precipitation; H2O; NO; atmospheric solar tides; microwave limb sounding; CO;

    Sammanfattning : Coupling mechanisms between different atmospheric layers are such that changes in middle atmospheric dynamics and composition have an effect on what happens at lower altitudes and on the climate. There is therefore a need to extend climate models to include higher altitudes and to perform measurements of the middle atmosphere. LÄS MER

  3. 7. Improved data analysis methods for the millimetre-wave observation of strato-mesospheric ozone and winds over Northern Sweden

    Författare :Rita Edit Kajtar; Mathias Milz; Uwe Raffalski; Victoria Barabash; Eliane Maillard Baras; Luleå tekniska universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Atmospheric science; Atmosfärsvetenskap;

    Sammanfattning : This thesis analyses and discusses the work done to improve an ozone retrieval method. The newly implemented method aims to invert emission spectra measured with the millimetre-wave radiometers KIMRA and MIRA2 at the Swedish Institute of Space Physics (IRF) in Kiruna. LÄS MER

  4. 8. 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

  5. 9. Investigation of Polar Mesosphere Summer Echoes in Northern Scandinavia

    Författare :Victoria Barabash; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Polar Mesosphere Summer Echoes; middle atmospheric dynamics; ionospheric disturbances; solar radiation; aerosol; MST radar; planetary waves; noctilucent clouds; Fysik; Physics; Fysik; rymdfysik; Space Physics;

    Sammanfattning : This PhD thesis deals with phenomena which are closely related to the unique thermal structure of the polar summer mesosphere, namely Polar Mesosphere Summer Echoes (PMSE). PMSE are strong radar echoes commonly observed by VHF MST radars from thin layers in the 80-90 km altitude interval at high latitudes during summer. LÄS MER

  7. 10. Recovery and validation of Odin/SMR measurements of mesospheric CO and H2O

    Författare :Francesco Grieco; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; mesosphere; microwave limb sounding; H2O; recovery; CO;

    Sammanfattning : Although life on Earth is concentrated in the troposphere, not only the processes happening here are of interest, since tropospheric processes are not the only ones that have an impact on the climate. Coupling mechanisms between different layers are such that changes in middle atmospheric dynamics and composition have an effect on what happens at lower altitudes. LÄS MER