Now showing items 19-38 of 44

    • Frequency Dependence of Ionospheric Electron Heating Around the Third Double Resonance 

      Frøystein, Ingeborg (Mastergradsoppgave; Master thesis, 2022-05-31)
      The partly ionized ionosphere responds differently to high power, high frequency radio waves based on the wave frequency, the wave power, the wave polarization, and the propagation angle relative to the magnetic field. Ionospheric modification experiments are conducted to investigate the responses and their dependencies, setting experimental constraints on the contributions from non-resonant collisional ...
    • The influence of mass loss on the dynamics of dust near the Sun 

      Klepper, Kassi (Mastergradsoppgave; Master thesis, 2021-12-28)
      The Parker Solar Probe (PSP) mission by NASA and the Solar Orbiter (SolO) mission by ESA are two recently launched missions that measure dust in the inner solar system. The dust is produced by fragmentation of meteoroids, which are large fragments of the asteroids and comets. The dust particles are small enough that their motion is affected by the radiation pressure force from the Sun. Dust fragments ...
    • Influence of Meteoric Aerosol particles on the Charge Balance in the Upper Mesosphere During ECOMA 2010 

      Svendsen, Åse (Master thesis; Mastergradsoppgave, 2011-12-15)
      This work is focused on the three sounding rocket launches during the ECOMA Geminids campaign in December 2010: One before the Geminids meteor shower, one at its peak and one some days after the peak. In this work, the main emphasis is on analyzing the results from electron and ion probes on the rockets, obtaining electron and ion density profiles, and comparing them with the measurements of meteoric ...
    • Installation and characterization of an electron bombardment ion source for a Space Simulation Chamber (SSC) 

      Dyrland, Karianne (Master thesis; Mastergradsoppgave, 2016-12-15)
      The primary focus of this thesis is the installation and characterization of an electron bombardment ion source for a Space Simulation Chamber (SSC). The goal is that the chamber can be used to test satellite and sounding rocket instrumentation, thus be capable of producing ionospheric plasma conditions, along with an ion beam that can simulate the velocity of a rocket or satellite relative to the ...
    • Interplanetary dust fluxes observed with Parker Solar Probe 

      Henriksen, Emil Gorseth (Master thesis; Mastergradsoppgave, 2020-06-29)
      The mission Parker Solar Probe (PSP) provides a new opportunity to make in-situ measurements of dust impacts closer to the Sun than ever before, eventually going as close as ∼ 10 solar radii or ∼ 0.05 AU. PSP can measure dust impacts from monopole measurements of the spacecraft’s electric potential to one of its antennas using its FIELDS instrument. In this work impact rates data is compared ...
    • Interstellar Dust in the Inner Heliosphere and Impact Detection Capabilities with ESA's Solar Orbiter Spacecraft 

      Henriksen, Aleksander Johan (Master thesis; Mastergradsoppgave, 2022-05-31)
      ESA’s Solar Orbiter spacecraft provides a new opportunity to investigate the inner heliosphere close to sun, by taking measurements with state-of-the-art instruments it will help uncover the mysteries of the Sun. Solar Orbiter is planned for a 7 year mission, reaching as close as 0.28 AU to the sun. Using a process called impact ionization, dust fluxes can be measured during the mission. Some ...
    • An Investigation of Magnetic Field Disturbances on the Ground and in the Mesosphere 

      Eriksen, Nina Kristine (Master thesis; Mastergradsoppgave, 2019-05-31)
      Geomagnetic field models can be a useful tool for when and where there are no measurements available, or access is limited, because of a highly spatially uneven magnetometer network around the globe. The same can be said for altitudes above the ground, but below the ionospheric current layer, where there exist no in situ measurements at the point of writing. Modelled geomagnetic disturbances have ...
    • An investigation of the spatial and temporal distribution of kinetic energy in the mesosphere. The high latitude mesosphere 

      Nordaunet, Ole Kalstad (Master thesis; Mastergradsoppgave, 2020-06-29)
      The mesosphere is perhaps the least explored region in the atmosphere with very few methods of observing. This thesis will primarily be exploring a new technique for measuring the distribution of kinetic energy in the mesosphere across a wide range of spatial and temporal scales. The method being used relies on correlation functions between pairs of meteor measurements. These measurements are made ...
    • A model for IS spectra for magnetized plasma with arbitrary isotropic velocity distributions 

      Enger, Eirik Rolland (Mastergradsoppgave; Master thesis, 2020-06-27)
      The plasma line in the incoherent scatter spectrum is known to provide information about the state of the ionosphere. However, it is weak in signal strength and therefore difficult to measure reliably and consistently. When high-energetic electrons (suprathermal electrons) are present in the ionosphere the plasma line echo power is enhanced and detectable by more radars. Recent measurements made by ...
    • Multifractals and their application to geospace data 

      Østvand, Lene (Master thesis; Mastergradsoppgave, 2008-06-02)
      In this thesis I first introduce multifractal theory and mathematical concepts for multifractal analysis. Different methods for different uses are described, with focus on a differentiating between coarse and fine theory approaches. Methods for analysing time series are also described, more specificly a direct method based on the coarse theory analysis, the wavelet transform modulus maxima ...
    • Na lidar measurements during the ECOMA/Geminids campaign with focus on Na peak density and temperature 

      Østerpart, Jørgen Olai Kristensen (Master thesis; Mastergradsoppgave, 2011-02)
      Using a resonance lidar, atomic Na (sodium) can be observed in the 80-110 km altitude range of the atmosphere. Na belongs to the alkali metal group and is highly reactive, so one could expect that it would quickly react with other particles and leave its atomic state. Its actual behaviour however includes the formation of relatively dense layers which, from the perspective of a stationary lidar, ...
    • Natural occuring oil seepages as a consequence of bottom trawling? 

      Hindenes, Sander (Mastergradsoppgave; Master thesis, 2023-05-31)
      Bottom trawling is used to capture fish species that live in the seabed. The damage on the seabed trawling causes has been discussed for many years. This thesis aims to investigate whether bottom trawling for sand eels can be a cause for some of the detected oil seepages in the North Sea. We investigated this using manual delineation of oil seepages in Synthetic Aperture Radar (SAR) satellite ...
    • A new Method for Estimating 3-Dimensional Ionospheric Currents from Ground-Based Magnetometers 

      Thom, Erik (Mastergradsoppgave; Master thesis, 2022-07-17)
      The ionosphere is a region of the upper atmosphere where a significant rate of photo-ionisation from solar ultraviolet radiation cause an increased plasma density. In this region a system of electrical currents flow, driven by electric fields generated by fluctuating dynamics within the Earths magnetosphere. These fluctuating dynamics are caused by interactions between the magnetosphere and the solar ...
    • On the Distribution of Meteoric Smoke Particles above Andøya, Norway, and Estimated Collection During a Summer Rocket Campaign 

      Larsen Greaker, Herman (Master thesis; Mastergradsoppgave, 2023-12-21)
      As meteoroids enter the Earth’s atmosphere, the majority will fully evaporate in the altitude region 70–110 km, due to the frictional heating from atmospheric interactions. The evaporated material is thought to re-condense and coagulate into nanometer sized particles called meteoric smoke particles (MSP). These particles are thought to be a central component in the formation of noctilucent clouds ...
    • On the internal physical conditions in dust probes: transport, heating and evaporation of fragmented dust particles 

      Antonsen, Tarjei (Master thesis; Mastergradsoppgave, 2013-12-13)
      We study the conditions within, and dynamics of fragmented mesospheric dust particles inside, the Faraday-cup type dust probe MUDD using numerical simulations with a dedicated model. The transport of singly charged fragments from impacting NLC particles on the main grid in MUDD, have been calculated on the basis of supplementary models of the neutral gas conditions and electric field structure within ...
    • On the Meteoric Smoke Particle Detector SPID: Measurements and analysis from the G-chaser rocket campaign 

      Trollvik, Henriette Marie Tveitnes (Master thesis; Mastergradsoppgave, 2019-06-01)
      The Smoke Particle Impact Detector (SPID), newly designed at the University of Tromsø, was launched from Andøya 09:13 UTC the 13. January 2019. SPID is designed to detect meteoric smoke particles (MSPs) in winter mesospheric conditions. The rocket had a velocity of 1600 ms-1 at ~55 km where the nosecone was separated. At ~ 60km, SPID detected a signal of 17nA on the middle plate. The dynamics of the ...
    • On Trapped Particle Dynamics in Rotating Frames 

      Helgeland, Aurora Driveklepp (Mastergradsoppgave; Master thesis, 2021-07-01)
      The rapid rotation of Jupiter and Saturn, combined with internal source of plasma provided by their moons Io and Enceladus respectively, creates a magnetodisk structure of the planetary magnetic field. The magnetodisk looks like a stretched dipole magnetic field in the equatorial region, where centrifugal force is largest. The centrifugal force, originating in the rotating frame, is known to have ...
    • Plasma cloud detection and diagnostics from arcing by conditional averaging 

      Nilsen, Kenneth (Master thesis; Mastergradsoppgave, 2017-06-06)
      Plasma cloud formation from arcing is experimentally studied. The arcs are formed by a high voltage set-up in the space simulation chamber at UiT. The plasma clouds are observed as large structures in the time series recorded by Langmuir probe and reference probe. By using the method of conditional averaging, the structures are accentuated. The electron cloud formed by arcing was found to be ...
    • Plasma line studies in relation to Naturally Enhanced Ion Acoustic Lines (NEIALs) 

      Knutsen, Joachim Sveia (Master thesis; Mastergradsoppgave, 2008-06-02)
      New to the ESR common programmes is the inclusion of plasma lines along with the standard ion power density spectrum. Using data from the IPY common programme, a programme that has been run all through the International Polar Year, we have gone through large amounts of analysed data trying to find periods in time that fulfils the known criteria for finding Naturally Enhanced Ion Acoustic Lines ...
    • Polar Mesospheric Winter Echoes - an analysis of selected cases 

      Ettestad, Kristine (Mastergradsoppgave; Master thesis, 2022-05-31)
      Polar Mesospheric Winter Echoes (PMWE) are strong coherent radar echoes, from the upper mesosphere at 55-85 km that are observed typically from end of August until beginning of May. Some models to explain PMWE formation suggest that they form because of turbulence in the atmosphere. Other models suggest that the PMWEs form like summer polar mesospheric echoes (PMSE) where charged dust particles ...