Blar i forfatter "Holmen, Silje Eriksen"

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    • Change in turbopause altitude at 52 and 70° N 

      Hall, Chris; Holmen, Silje Eriksen; Meek, Chris; Manson, Alan; Nozawa, Satonori (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-02-26)
      The turbopause is the demarcation between atmospheric mixing by turbulence (below) and molecular diffusion (above). When studying concentrations of trace species in the atmosphere, and particularly long-term change, it may be important to understand processes present, together with their temporal evolution that may be responsible for redistribution of atmospheric constituents. The general ...

    • Neutral atmosphere temperature trends and variability at 90 km, 70°N, 19°E, 2003-2014 

      Holmen, Silje Eriksen; Hall, Chris; Tsutsumi, Masaki (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-06-27)
      Neutral temperatures at 90 km height above Tromsø, Norway, have been determined using ambipolar diffusion coefficients calculated from meteor echo fading times using the Nippon/Norway Tromsø Meteor Radar (NTMR). Daily temperature averages have been calculated from November 2003 to October 2014 and calibrated against temperature measurements from the Microwave Limb Sounder (MLS) on board Aura. ...

    • Trends and variability of polar mesopause region temperatures attributed to atmospheric dynamics and solar activity 

      Holmen, Silje Eriksen (Doctoral thesis; Doktorgradsavhandling, 2016-12-19)
      The mesopause region can be considered a "boundary region" between the neutral atmosphere, where atmospheric constituents and momentum are transported mainly by winds and turbulent eddies, and the ionosphere, where the main transport mechanism is molecular diffusion. In the mesopause, complex interactions between dynamics and photochemistry occur, and we are far from a complete understanding of these ...