A Study of Sediment Transport in Norwegian Glacial Rivers, 1969

From original report: The Norwegian Water Resources and Electricity Board, Institute of Water Resources, Department of Hydrology, Oslo. September 1970. Report No. 6/70.Permission to translate this Norwegian report was kindly given by G. Østrem, and the translation by Helga Carstens, while she was in Alaska, is greatly appreciated. Unfortunately, Mrs. Carstens returned to her homeland, Norway, before final editing of the manuscript could be completed. Consequently, any errors in translation are due to the editor, and for these errors, the editor apologizes to the authors. Not included in this translation is an English summary contained in the original report. To keep printing costs down, the original figures and tables, which fortunately had English titles, are used in this translation. This report is the first of a series of reports being prepared for the Norwegian Water Resources and Electricity Board. The second report for 1970 has been published with an English summary and contains an extension of the data contained in the 1969 report. Because this work deals with problems very similar to those in Alaska, it was decided to translate the first report and circulate a limited number of copies to workers in the U. S. and Canada. Research very similar to the Norwegian work was initiated in Alaska under the editor's direction in cooperation with the U. S. Geological Survey. -- G. L. Guymon.This work and the translation of this report were supported by funds provided by the United States Department of the Interior, Office of Water Resources Research (Proj. A-042-ALAS), as authorized under the amended Water Resources Act of 1964

Studietur i Latvia 20.-21. juni 2015

Hensikten med studieturen, som ble gjennomført etter NJF-kongressen i Riga, var å bli bedre kjent med landbruket i Latvia og landet generelt. Et annet mål med turen var å treffe forskere og gårdbrukere for å diskutere eventuelt prosjektsamarbeid. Studieturen ble planlagt og organisert av Ievina Sturite ved Bioforsk. Hun kommer opprinnelig fra Latvia og har derfor god kjennskap til landbruket og landbruksforskning i landet. Deltakerne på turen kom fra ulike Bioforskstasjoner: Ievina Sturite fra Tjøtta, Grete Lene Serikstad og Kirsty McKinnon fra Tingvoll og Liv Østrem fra Fureneset

Stagnation and mass loss on a Himalayan debris-covered glacier: processes, patterns and rates

This research was supported financially by the University Centre in Svalbard (UNIS), National Geographic Society GRANT #W135-10, The Natural Environmental Research Council and the European Commission FP7-MC-IEF.The ablation areas of debris-covered glaciers typically consist of a complex mosaic of surface features with contrasting processes and rates of mass loss. This greatly complicates glacier response to climate change, and increases the uncertainty of predictive models. In this paper we present a series of high-resolution DEMs and repeat lake bathymetric surveys on Ngozumpa Glacier, Nepal, to study processes and patterns of mass loss on a Himalayan debris-covered glacier in unprecedented detail. Most mass loss occurs by melt below supraglacial debris, and melt and calving of ice cliffs (backwasting). Although ice cliffs cover only ∼5% of the area of the lower tongue, they account for 40% of the ablation. The surface debris layer is subject to frequent re-distribution by slope processes, resulting in large spatial and temporal differences in debris-layer thickness, enhancing or inhibiting local ablation rates and encouraging continuous topographic inversion. A moraine-dammed lake on the lower glacier tongue (Spillway Lake) underwent a period of rapid expansion from 2001 to 2009, but later experienced a reduction of area and volume as a result of lake level lowering and sediment redistribution. Rapid lake growth will likely resume in the near future, and may eventually become up to 7 km long.Publisher PDFPeer reviewe

Air Temperature Distribution and Energy-balance Modelling of a Debris-covered Glacier

Near-surface air temperature is an important determinant of the surface energy balance of glaciers and is often represented by a constant linear temperature gradients (TGs) in models. Spatiotemporal variability in 2 m air temperature was measured across the debris-covered Miage Glacier, Italy, over an 89 d period during the 2014 ablation season using a network of 19 stations. Air temperature was found to be strongly dependent upon elevation for most stations, even under varying meteorological conditions and at different times of day, and its spatial variability was well explained by a locally derived mean linear TG (MG–TG) of −0.0088°C m−1. However, local temperature depressions occurred over areas of very thin or patchy debris cover. The MG–TG, together with other air TGs, extrapolated from both on- and off-glacier sites, were applied in a distributed energy-balance model. Compared with piecewise air temperature extrapolation from all on-glacier stations, modelled ablation, using the MG–TG, increased by 4% using the environmental ‘lapse rate’. Ice melt under thick debris was relatively insensitive to air temperature, while the effects of different temperature extrapolation methods were strongest at high elevation sites of thin and patchy debris cover

Internal structure and significance of ice-marginal moraine in the Kebnekaise Mountains, northern Sweden

Despite a long history of glaciological research, the palaeo-environmental significance of moraine systems in the Kebnekaise Mountains, Sweden, has remained uncertain. These landforms offer the potential to elucidate glacier response prior to the period of direct monitoring and provide an insight into the ice-marginal processes operating at polythermal valley glaciers. This study set out to test existing interpretations of Scandinavian ice-marginal moraines, which invoke ice stagnation, pushing, stacking/dumping and push-deformation as important moraine forming processes. Moraines at Isfallsglaciären were investigated using ground-penetrating radar to document the internal structural characteristics of the landform assemblage. Radar surveys revealed a range of substrate composition and reflectors, indicating a debris- ice interface and bounding surfaces within the moraine. The moraine is demonstrated to contain both ice-rich and debris-rich zones, reflecting a complex depositional history and a polygenetic origin. As a consequence of glacier overriding, the morphology of these landforms provides a misleading indicator of glacial history. Traditional geochronological methods are unlikely to be effective on this type of land- form as the fresh surface may post-date the formation of the landform following reoccupation of the moraine rampart by the glacier. This research highlights that the interpretation of geochronological data sets from similar moraine systems should be undertaken with caution

Reliable electric power conversion for connecting renewables to the distribution network

When connecting distributed power generation systems to the utility grid, a power converter is normally placed between the main grid and the local micro-grid, at the point of common coupling. In order to synchronize the converter to the utility grid voltages, a synchronizing circuit is needed. A common way of doing this, is to use a phase-locked loop (PLL). This circuit estimates a voltage reference angle which is fed to the control system of the power converter. One of the simplest PLL designs is based on the grid voltage zero crossings. The drawback of this method is that no information about the grid voltage conditions is available in the interval between the zero crossing. The design has been implemented and successfully tested on a Field Programmable Gate Array (FPGA) circuit connected to a power converter. A more advanced way of designing a PLL is by using voltage vector control. The method is more complex and time consuming. On the other hand, information about the grid voltage condition is always available. The design fails to run properly if the grid voltages are unbalanced or distorted. In order to improve the performance, a multi-variable filter tuned at nominal grid frequency may be added. This solution has been implemented on an FPGA circuit and successfully tested. The multi-variable filter will cause an angle displacement if the grid frequency deviates from its nominal value. The author proposes a method called Adaptive Signal Cancellation (ASC), in order to make the PLL frequency independent. The method is based on a method called Delayed Signal Cancellation (DSC) where the grid voltages are inputted and symmetric voltage components are outputted. Instead of delaying signals, the ASC is phase shifting signals, obtaining approximately the same performance. In addition to providing the control circuit with an estimated voltage reference angle, the circuit also outputs signals determining grid voltage conditions: voltage level, symmetry and frequency. These signals can be used in an overhead control structure taking care of power management and protection

Including debris cover effects in a distributed model of glacier ablation

Distributed glacier melt models generally assume that the glacier surface consists of bare exposed ice and snow. In reality, many glaciers are wholly or partially covered in layers of debris that tend to suppress ablation rates. In this paper, an existing physically based point model for the ablation of debris-covered ice is incorporated in a distributed melt model and applied to Haut Glacier d’Arolla, Switzerland, which has three large patches of debris cover on its surface. The model is based on a 10 m resolution digital elevation model (DEM) of the area; each glacier pixel in the DEM is defined as either bare or debris-covered ice, and may be covered in snow that must be melted off before ice ablation is assumed to occur. Each debris-covered pixel is assigned a debris thickness value using probability distributions based on over 1000 manual thickness measurements. Locally observed meteorological data are used to run energy balance calculations in every pixel, using an approach suitable for snow, bare ice or debris-covered ice as appropriate. The use of the debris model significantly reduces the total ablation in the debris-covered areas, however the precise reduction is sensitive to the temperature extrapolation used in the model distribution because air near the debris surface tends to be slightly warmer than over bare ice. Overall results suggest that the debris patches, which cover 10% of the glacierized area, reduce total runoff from the glacierized part of the basin by up to 7%

Development of Chiral Gold(III)-complexes and Studies of Their Catalytic Activity

The purpose of this master project was to synthesise chiral ligands and coordinate these to gold(III), thereby developing novel chiral gold(III)-complexes. These complexes were then used as gold-catalysts in cyclopropanation reactions in which their catalytic activity and their enantioselectivity could be measured. Six different squaramide ligands were synthesised by the addition of different amines to squaric ethyl ester, resulting in yields varying from 7% to 68%. Gold(III)-coordination of the squaramides was unsuccessful. After the failure of creating gold(III)-complexes of squaramides, an iminoisoindoline was synthesised (94%) and subsequent gold(III)-coordination resulted in iminoisoindoline-Au(III)-complex (94%). Gold(III)-coordination to several commercially available oxazoline-based ligands were also attempted. Gold(III)-complex 10 was successfully coordinated and crystallized (63%), and the structure was confirmed by X-ray crystallography. Gold(III)-complex 12 had already been developed during the pre-master project and was repeated here (22%). Gold(III)-coordination of oxazoline-based ligand 13 resulted in a mixture of gold(III)-complex 14 and several other products. Complex 14 was attempted isolated from the mixture, without success. Gold(III)-coordination of oxazoline-based ligand 15 resulted in a complex mixture which did not contain the wanted gold(III)-complex. The catalytic ability of the successful gold(III)-complexes 8, 10 and 12, the mixture containing gold(III)-complex 14 and the squaramide 4[AuCl4]-salt were tested in cyclopropanation reaction of propargyl esters with vinyl substrates, affording the cyclopropanation products in 63-89% yield, with different cis:trans ratios. Enantioselectivity of the cyclopropanation products tested by chiral HPLC, but none of the products showed any enantiomeric excess