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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...