Aspects of in situ angular scattering measurements in contrasting waters

Rapid changes are observed in oceanic and coastal environments around the world due to global temperatures increases, ocean acidification and changing weather patterns - anthropogenic climate change. These changes have large effects on the ecosystems of the ocean. In order to understand the effects and possibly mitigate their consequences, it is necessary to increase and improve the environmental monitoring of the ocean. Optical properties of natural waters within the visible spectrum is closely linked to properties of phytoplankton, the foundation of oceanic ecosystems, as well as other particles on the micrometer and sub-micrometer scale in the water mass. Optical measurements can thus give us valuable information about the particle content of the water and the state of the ecosystem. The volume scattering function (VSF) is a fundamental optical property describing how much light is scattered by a medium and in what direction the light is scattered. In natural waters, by far most of the light is scattered in the very forward direction, which makes it technically challenging to measure the VSF. The LISST-VSF is the first commercially available instrument for field measurements of the VSF over a large angular domain. To trust the measurements, it is important to validate the performance of instrument and identify any error sources, in particular the valid range of the instrument, given that scattering coefficients of natural waters can span three orders of magnitude. In this thesis, I have characterised LISST-VSF measurements using both in situ measurements of highly contrasting water types, controlled laboratory measurements, and Monte Carlo simulations of instrument geometry. Similar aspects have been investigated for the LISST-200X, which measures the VSF at angles 0.04-13˚ at 670 nm. In Paper I, these two instruments are calibrated and validated using polymer beads and in situ measurements spanning from clear waters on the North Pole to highly turbid glacial meltwater. The measurements demonstrated that due to instrument design, the LISST-200X only gives valid scattering measurements in moderate-to-turbid waters. The LISST-VSF gives valid measurements also in clear waters (however with a loss in precision), but is limited by multiple scattering errors in more turbid waters. Multiple scattering effects on LISST-VSF measurements are investigated in detail in in Paper II and III. For this purpose, a Monte Carlo simulation was developed and validated with experimental data, and subsequently used to simulate LISST-VSF measurements with Fournier-Forand and Henyey-Greenstein phase functions. We demonstrated that the multiple scattering can yield uncertainties of 10% when the scattering coefficient is 1 m-1, which significantly restricts the accurate measurement range of LISST-VSF. LISST-200X is less affected by this error due to its shorter path length. Scattering can be an error source for other optical measurements as well. In Paper IV, we attempt to correct in situ depth profiles of absorption coefficients measured with the ac-s instrument using VSF measurements collected with the LISST-VSF in coastal waters. We show that this method does not show a clear and consistent improvement over existing methods, which are simpler to use but make strong assumptions about absorption and scattering properties. The discrepancies in the VSF correction can be attributed to several different confounding factors, such as spatial variability and multiple scattering, which are exceedingly propagated to the corrected absorption values. Nevertheless, VSF measurements are found useful to analyze the scattering error. We show that the VSF between 5-90˚ can contribute significantly to the scattering error, depending on the phase function and the reflectance efficiency of the reflective tube. Moreover, by simulating the VSF wavelength-dependency using Mie theory, we show that particle sub-populations with diameters close to the wavelength can explain why scaling the scattering error with the scattering coefficient sometimes fails.Doktorgradsavhandlin

Vertical diffusivity and oxygen concentrations in a fjord basin - A case study of the deep basin in Masfjorden

The basin layer in a sill fjord is isolated from the coast, and may become hypoxic or anoxic if the renewal frequency is low. Deep water renewals and vertical mixing are the physical processes which affects the oxygen concentration in the basin. The temporal evolution of density and oxygen concentrations in the basin layer in Masfjorden, a sill fjord in western Norway, have been studied based on observations of hydrographic data obtained during February 2019 - March 2021. The vertical diffusivity in the basin layer were estimated from the observations and model results from the hydrodynamic model NorFjords160 by the budget method presented in Stigebrandt and Aure (1989). The observed vertical diffusivity was used in further calculations to find the oxygen consumption rate, and in an attempt to see how a partial renewal affects the oxygen concentrations close to the bottom in the basin. The hydrographic data showed a region with oxygen stressed conditions in the basin layer with concentrations around 2.5 mL L^(-1). Two shallow partial renewals occurred in the upper parts of the basin layer during summer of 2019 and 2020. The the mean oxygen concentration in the basin declined during the observational period, while the oxygen concentration at 450 m increased during the same period. The comparison of the volume mean vertical diffusivity in the observations and in the model suggests a realistic, but lower density reduction rate, in the model.Masteroppgave i meteorologi og oseanografiGEOF399MAMN-GEO

3D and 4D Modeling of Ignimbrite Eruptions

The need to model the Yellowstone magma chamber and other possible sites for ignimbrite eruption has been accelerated by the development of the areas surrounding the volcanoes. Early detection of eruptions is the most important aspect when trying to reduce casualties from an eruption. The magma chamber at Yellowstone has been mapped previously using Seismic data and other methods, but more information is needed to predict the next eruptive event. Through the use of previous research by Dr. de Silva and Dr. Gosnold, it is possible to create a representative model for the magma chamber. The model is created using a combination of ARC, Surfer, and Voxler. Using these programs and pre-existing geothermal data, the relation between the brittle-ductile zone and the magma chamber can be modelled. Through this relatively new method, it will hopefully be possible to put a timetable on the next major eruptive event

Rescue Missions in the Mediterranean and the Legitimacy of the EU’s Border Regime

In the last seven years, over twenty thousand people have died trying to reach Europe by crossing the Mediterranean Sea. Rescue missions by private actors and NGOs have increased because both national measures and measures by the EU’s border control agency, Frontex, are often deemed insufficient. However, such independent rescue missions face increasing persecution from national governments, Italy being one example. This raises the question of how potential migrants and dissenting citizens should act towards the EU border regime. In contrast to the literature, which mainly addresses migration on the basis of justice requirements, this article focuses on the legitimate authority of the EU’s border regime. Focusing on the legitimacy criteria for states’ claims to regulate migration opens a fruitful normative perspective, given the pervasive disagreement over the content of justice in migration. What reasons for compliance and non-interference does legitimacy supply for potential immigrants and dissenting citizens? And what legitimacy standard may be appropriate for the power that individual states claim over potential immigrants? We argue that, even assuming a minimal legitimacy standard for the state-migrant relationship, the structure of the EU’s border regime exhibits unique features, which cause it to stand in tension with such a standard. By coordinating its Member States’ border regimes, especially through Frontex, the EU claims and exercises power over potential immigrants. However, the asymmetrical delegation of state powers to the EU means that the power involved in regulating European borders is, in core respects, unaccountable. This unaccountability, we argue, is significant for the legitimacy of the EU’s border regime. This article sheds new light on the morality of unauthorised rescue missions by assessing the permissibility of resistance to the EU’s border regime

Næringslivets deltakelse i EUs 7. rammeprogram for forskning og teknologisk utvikling

Dette er en vurdering av strategi og organisering med vekt på små og mellomstore bedrifte

A closer look at the relationship between innovation and employment growth at the firm level

This paper considers in detail how different types of innovation (products, processes, patents, combinations) are related to different employment growth characteristics (exit or survival, with employment upscaling or downscaling at moderate or high rates). Using Norwegian Community Innovation Survey (CIS) data collected in 2008 and merged with public employer-employee registers for the years 2004-2010, it finds that growth persists over time, and increases the probability that ‘bundles’ of complementary product and process innovations are introduced that strengthen employment further. Downscaling also persists, and reduces the probability that ‘bundles’ are introduced that could turn the negative trend. While standalone product innovations follow in the wake of rapid expansion, such have limited impact on employment beyond sustaining growth at moderate levels. Standalone process innovations, by contrast, tend to be introduced after a period of moderate growth, yet, might give rise to large subsequent expansions. These results demonstrate that innovation and employment growth are multi-dimensional characteristics of the firm, which are interlinked with each other in virtuous or vicious circles that unfolds over tim

Utenlandske investeringer i norsk FoU

Norges forskningsråd (NFR) og Innovasjon Norge (IN) ble i Forskningsmeldingen (St.meld. nr. 20 2004–2005 Vilje til forskning) gitt i oppdrag å utrede tiltak som kan bidra til å øke de utenlandske investeringene i norsk forskning og utvikling, for på denne måten å bidra til å øke Norges totale FoU-innsats. Dette prosjektet ble gjennomført høsten 2005 med Norges forskningsråd som ansvarlig og spesialrådgiver Rikard Wærø som prosjektleder. Som en del av dette arbeidet ble NIFU STEP bedt om å kartlegge status for utenlandske investeringer i FoU i Norge. Dette oppdraget omfattet en kartlegging av hvilke kilder til slike investeringer som måtte finnes; deres absolutte og relative betydning samt deres fordeling på utførende sektorer