The behavior of the autumn and winter weather pattern over Europe and Eurasia was investigated during two periods of high and low ice concentration in September over the Kara-Siberian sea. A statistically significant anomalous energy flux from the east Siberian sea to the atmosphere was detected during October of low ice years. Furthermore, an anomalous behavior in the atmospheric circulation was ...

The use of long-range memory models as a description of the noise in Earth surface temperatures has increased the recent years, and as a measure of the persistence for such time series we have the Hurst exponent. It is known that sea surface temperatures are more persistent than land temperatures, and that global temperatures are more persistent than local temperatures. We also know that the persistence ...

Oppgaven bygger på målinger av plasmadrift i den øvre atmosfære over Ny-Ålesund, Svalbard. Som målemetode er brukt "spaced receivers" metoden. I kap. 2 er satt opp modeller for solvind, magnetosfære og ionosfære og en ser på fenomen som forplanter seg fra solvinden til ionosfæren. Ved hjelp av disse modeller beregnes så drift av plasma i ionosfæren. I kap. 3 beskrives målemetoden. Diffraksjonsmekanismen ...

Petermann Glacier drains about 4% of the Greenland ice sheet area, with at least 80% of its mass loss through basal melting of the floating ice shelf. Utilizing a high-resolution coupled ice-shelf-ocean model, we aim at understanding the ocean circulation in Nares Strait and the mechanism of oceanic heat supply below the ice shelf as well as quantifying the basal mass loss. The numerical model is ...

This work is presenting a fully numerical approach for the direct solution of the Poisson equation for the electrostatic potential given by an arbitrary charge density. Efficient solution of this equation is important in many fields of science, where the current work is dealing with nuclear and electronic potential calculations, used in the field of computational chemistry. The equation is solved ...

Numerical simulations of reduced fluid models describing magnetized plasmas have previously been used to study the boundary of fusion plasmas extensively. A common approximation applied to these models is the so-called Boussinesq approximation. One of the requirements for the Boussinesq approximation to be applicable is that the background particle density is significantly higher than the fluctuations ...

The thesis discusses the possibility of using ultrawideband (UWB) radar to detect breast cancer. At the present time, X-ray mammography and ultrasound are the golden standard imaging techniques for detection and evaluation of breast cancer, but they both have their limitations. UWB radar utilizes the difference in dielectric properties between a tumor and the surrounding healthy tissue. By interpreting ...

Long-term hydrographic time series data from two fixed stations in the northern Norwegian fjords Malangen and Balsfjorden from the period 1980 - 2022 have been examined. The data have been supplemented with model results from the ocean model NorFjords160 over the period April 1st 2017 to December 31st 2022. To gain a deeper understanding of the oceanographic variability and change, the environmental ...

In this work we investigated the relation between type-II ion outflows and NEIALs. Currently, several ion outflows acceleration mechanisms and NEIALs generation theories have been proposed. In the first part of this thesis we review the most important works regarding these two processes. In the second part we present the results of our analysis, together with some unexpected events which were not ...

The main objective of this thesis is to optimize the thickness of sensitive polymer layer highly doped with Cryptophane-A for methane pre-concentration and to make the existing sensor more stable and selective towards methane. In recent years, methane detection has become a hot topic due to the strong impact of methane on the global warming and the climate change. There has also been rising ...