Sökning: "thermosphere"

Visar resultat 1 - 5 av 6 avhandlingar innehållade ordet thermosphere.

  1. 1. Empirical Modeling of Solar Induced Variations of Nitric Oxide in the Upper Mesosphere and Lower Thermosphere

    Författare :Joonas Kiviranta; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; mesosphere; nitric oxide; Odin; thermosphere; empirical modeling; SANOMA;

    Sammanfattning : Nitric Oxide (NO) is produced by solar photolysis and auroral activity in the upper mesosphere and lower thermosphere region and can, via transport processes, eventually impact the ozone layer in the stratosphere. This thesis uses measurements of NO taken between 2004 and 2016 by the Odin Sub Millimetre Radiometer (SMR) to build an empirical model which links the prevailing solar and auroral conditions with the measured number density of NO. LÄS MER

  3. 2. Solar Forcing of Nitric Oxide in the Upper Atmosphere

    Författare :Koen Hendrickx; Linda Megner; Jörg Gumbel; Bernd Funke; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; nitric oxide; NO; mesosphere; lower thermosphere; MLT; energetic particle precipitation; EPP; medium energy electrons; MEE; SOFIE; SNOE; WACCM; POES; atmosfärvetenskap och oceanografi; Atmospheric Sciences and Oceanography;

    Sammanfattning : The forcing of the Sun on Earth's atmosphere manifests itself via solar radiation and energetic particle precipitation (EPP), which variations are most noticeable in the upper regions of the atmosphere. A key species in the lower thermosphere, which is influenced by solar forcing, is nitric oxide (NO). LÄS MER

  4. 3. Rocket-borne in situ measurements in the middle atmosphere

    Författare :Jonas Hedin; Jörg Gumbel; Markus Rapp; Ove Havnes; Stockholms universitet; []
    Nyckelord :rocket measurements; noctilucent clouds; meteoric smoke; nightglow; mesosphere; aerodynamics; NATURAL SCIENCES; NATURVETENSKAP; atmosfärvetenskap; Atmospheric Sciences;

    Sammanfattning : The Earth's mesosphere and lower thermosphere in the altitude range 50-130 km is a fascinating part of our atmosphere. Complex interactions between radiative, dynamical, microphysical and chemical processes give rise to several prominent phenomena, many of those centred around the mesopause region (80-100 km). LÄS MER

  5. 4. Observations of water vapour in the middle atmosphere

    Författare :Stefan Lossow; Jörg Gumbel; Jacek Stegman; Daniel R. Marsh; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; water vapour; mesosphere; stratosphere; dynamics; Odin satellite; limb sounding; microwave; tropics; polar winter; Meteorology; Meteorologi; meteorologi; Meteorology;

    Sammanfattning : Water vapour is the most important greenhouse gas and plays a fundamental role in the climate system and for the chemistry of the Earth's atmosphere. This thesis presents observations of water vapour in the middle atmosphere with a particular focus on the mesosphere. LÄS MER

  7. 5. 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