Institutt for fysikk og teknologi: Recent submissions
Now showing items 1-20 of 1284
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Propagating information like waves in GNNs
(Master thesis; Mastergradsoppgave, 2024-05-31)Various deep learning architectures are appearing in the field of machine learning with the goal of being able to handle various types of data, or solving inherent problems within the networks. In this thesis, we propose the idea of creating architectures based on physics partial differential equations (PDEs), where we transfer the known properties of PDEs as a method of introducing inductive bias ... -
Bruk av solceller i rehabilitering av gjenreisningsboliger i Nord-Norge – et klimaperspektiv
(Master thesis; Mastergradsoppgave, 2024-05-31)Denne masteroppgaven utforsker potensialet for solceller i rehabilitering av gjenreisningsboliger i Nord-Norge gjennom en detaljert livssyklusanalyse (LCA) for å evaluere miljøpåvirkningen av solskifertak sammenlignet med tradisjonelle skifertak. Ved hjelp av modellering i PVsyst v6.88, ble energiproduksjonen for et system på 11m2 med nominell ytelse 1.4 kW simulert og effekten av viktige ... -
Exploring methane detection with Sentinel-2 data: capabilities for monitoring landfill emissions
(Master thesis; Mastergradsoppgave, 2024-06-01)Methane is an extremely potent greenhouse gas, as it is about 80 times more effective at trapping heat than carbon dioxide. To mitigate global warming and the related consequences, reducing our emissions of methane is crucial. Therefore, being able to detect unknown releases and monitor the effects of emission mitigation efforts is essential. A few satellites with methane monitoring as one of their ... -
Antarctic ice shelf response to ocean tides and atmospheric pressure variations using satellite interferometry
(Master thesis; Mastergradsoppgave, 2024-06-02)Ice shelves, the floating extensions of the Antarctic ice sheet, are supporting the upstream ice and regulates the outflow into the ocean. They are a key component in future predictions of sea level rise, as their direct contact with both the ocean and the atmosphere makes them subject to changing climatic conditions. This thesis aims to investigate how Fimbulisen, a large ice shelf in East ... -
Uncertainty Guided Polygon Generation for Building Detection
(Mastergradsoppgave; Master thesis, 2024-06-01)Enhanced accuracy of building detection algorithms has the potential to benefit a wide array of applications, including urban planning, environmental monitoring, and disaster response efforts. However, building extraction algorithms struggle with robustness due to among others, occlusions from vegetation and shadows of nearby tall buildings, complex building shapes, and a large distributional shift ... -
Implementing renewable energy technologies in buildings: impacts of local-specific conditions, intermittency and volatile power markets
(Master thesis; Mastergradsoppgave, 2024-05-31)Increased implementations of small-scale renewable energy technologies in buildings can potentially save costs and reduce greenhouse gas emissions. The aim of this thesis is to analyse the total costs and climatic impact of implementations in major cities in Norway. Basing the analysis in data of hourly resolutions captures effects of how intermittency and volatility in the power market ... -
Seasonal Thermal Energy Storage Using Sand Batteries: Feasibility and Economic Analysis in Northern Norway
(Master thesis; Mastergradsoppgave, 2024-05-31)The global shift from fossil fuels to renewable energy sources necessitates effective energy storage solutions to address the intermittent nature of renewable power. This thesis investigates the feasibility and economic viability of using sand batteries for seasonal thermal energy storage in Northern Norway. Sand batteries leverage the high heat capacity of sand to store excess thermal energy during ... -
Assessing ice rate and ice load at Davvi wind farm using WRF model with wind turbine scheme
(Master thesis; Mastergradsoppgave, 2024-05-31)Wind farms located in cold climates are exposed to temperatures under the design limit and icing conditions, where the main challenges are production losses and mechanical failures. The goal of this thesis is to investigate the impact related to icing on the location of Davvi wind farm using Weather Research and Forecasting (WRF) model. The thesis have investigated the icing intensity and production ... -
Stellar CCD Photometry in the Auroral Zone
(Master thesis; Mastergradsoppgave, 2000-12)Observing pulsating stars in the auroral zone, seemed for many years to be an impossible task. Due to the aurora, the sky is bright and rapidly changing. Precise photometry could only be performed on stars down to 7 th. magnitude.<p> <p>A new instrument for continuous photometry, with the use of CCD technology, and windowed readout, is developed by the Astrophysics group at the University of ... -
An Investigation of Turbulence and Intermittency in the High-Latitude Ionosphere: A Multi Case Study
(Master thesis; Mastergradsoppgave, 2024-06-03)High-latitude electron density irregularities can affect technology such as the Global Navigation Satellite Services (GNSS) by degrading radio signals. These irregularities are not fully understood. In this work we investigate turbulence and intermittency in varying regions of the high- latitude ionosphere using the structure function, empirical flatness and probability density function. Our ... -
Seasonal and interannual variability in hydrography and currents along the Nansen Legacy transect across the Barents Sea
(Master thesis; Mastergradsoppgave, 2023-12-20)The Barents Sea is an Arctic shelf sea that is an important site forwater mass formation and transformation. It is characterized by interactions between Atlanticand Arctic-originWaters, and by strong seasonality in terms of alternating atmospheric and sea-ice conditions throughout the year. How these aspects impact the seasonal evolution of the water column properties is yet to be fully ... -
Leveraging tensor kernels to reduce objective function mismatch in deep clustering
(Journal article; Tidsskriftartikkel; Peer reviewed, 2023-12-29)Objective Function Mismatch (OFM) occurs when the optimization of one objective has a negative impact on the optimization of another objective. In this work we study OFM in deep clustering, and find that the popular autoencoder-based approach to deep clustering can lead to both reduced clustering performance, and a significant amount of OFM between the reconstruction and clustering objectives. To ... -
Extent, duration and timing of the sea ice cover in Hornsund, Svalbard in 2014–2023
(Journal article; Tidsskriftartikkel; Peer reviewed, 2024-02-27)The Sentinel-1A/B synthetic aperture radar (SAR) imagery archive between 14 October 2014 and 29 June 2023 was used in combination with a segmentation algorithm to create a series of binary ice/open-water maps of Hornsund fjord, Svalbard, at 50 m resolution for nine seasons (2014/15 to 2022/23). The near-daily (1.57 d mean temporal resolution) maps were used to calculate sea ice coverage for the ... -
Offshore Wind Prediction with Graph Neural Networks
(Mastergradsoppgave; Master thesis, 2024-06-14)Offshore wind energy, especially in regions like the Norwegian Arctic, is a promising source of renewable energy. Graph Neural Networks (GNNs) have shown potential in modeling complex systems like weather, making them suitable for improving wind resource assessments. This thesis investigates the use of GNNs for predicting offshore wind patterns, utilizing high-resolution Synthetic Aperture Radar ... -
Recent Changes in Mid-latitude Wave Propagation
(Mastergradsoppgave; Master thesis, 2024-06-12)In recent years climate change in the polar areas has attracted a lot of attention. Not only for its consequences in polar areas, but also for its possible effects on lower latitudes. A reduced temperature gradient between the polar areas is expected to weaken the mid-latitude jet stream. This weaker jet stream is hypothesised to lead to a reduction in the propagation velocity of atmospheric Rossby ... -
Wind resource assessment using LiDAR
(Mastergradsoppgave; Master thesis, 2024-06-07)This thesis presents a comprehensive wind resource assessment for the expansion of the Fakken wind park in Norway, leveraging Light Detection and Ranging (LiDAR) technology. The measurement campaign conducted from December 2022 to June 2023, aims to detail LiDAR measurement methodologies, analyze collected data, and estimate wind energy production. -
Dual Radar Detections of Meteors Using Calibrated EISCAT UHF Data
(Mastergradsoppgave; Master thesis, 2024-06-03)The atmosphere of Earth experiences a continuous entry of particles of various sizes originating from several sources. Meteoroids, which are called meteors when entering the atmosphere, are particles that can be measured by radars through scattering off the meteor head plasma which forms around the meteor. These measurements can give information on the processes the meteor undergoes as it travels ... -
Investigation into the photon interaction of small mesospheric dust and its impact on the ionospheric charge balance
(Mastergradsoppgave; Master thesis, 2024-05-31)This thesis investigates the charging mechanisms of nano-sized meteoric smoke particles (MSP) in the mesosphere, with a particular focus on the photoionization and photodetachment processes on MSP assuming different materials. The study begins with three theoretical chapters that lay the ground- work for understanding relevant topics like the atmospheric region in question, MSP, the solar ... -
Pulsating Aurora: Optical observations and modelling of the time-variation of ionospheric response to precipitation of pitch-angle-scattered electrons from the magnetosphere
(Mastergradsoppgave; Master thesis, 2024-01-29)This thesis explores the mechanisms governing pulsating auroras by combining observational analysis with theoretical simulations using the AURORA model. The AURORA model simulates electron transport and ionospheric responses, playing a key role in replicating the abrupt onset precipitation of electrons from source altitudes at 3RE, 4.4RE, 6.1RE, and 7.6RE. Eight events of pulsating aurora were ... -
The Role of Clouds in Arctic Climate
(Mastergradsoppgave; Master thesis, 2024-05-14)Anthropogenic climate change is causing the Arctic to warm faster than any other region on Earth, a phenomenon also known as Arctic amplification. The warming and its consequences induce, amongst other things, a change in clouds, impacting their role in the Arctic climate by introducing a feedback. Clouds play an important role in the global radiation budget. They cool the surface by reflecting ...