Viser treff 4715-4734 av 4757

    • Widespread and accelerating glacier retreat on the Lyngen Peninsula, northern Norway, since their 'Little Ice Age' maximum 

      Stokes, Chris R.; Andreassen, Liss Marie; Champion, Matthew R; Corner, Geoffrey D. (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-03-06)
      The recession of mountain glaciers worldwide is increasing global sea level and, in many regions, human activities will have to adapt to changes in surface hydrology. Thus, it is important to provide up-to-date analyses of glacier change and the factors modulating their response to climate warming. Here we report changes in the extent of >120 glaciers on the Lyngen Peninsula, northern Norway, where ...
    • Widespread natural methane and oil leakage from sub-marine Arctic reservoirs 

      Serov, Pavel; Mattingsdal, Rune; Winsborrow, Monica; Patton, Henry; Andreassen, Karin Marie (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-03-30)
      Parceling the anthropogenic and natural (geological) sources of fossil methane in the atmosphere remains problematic due to a lack of distinctive chemical markers for their discrimination. In this light, understanding the distribution and contribution of potential geological methane sources is important. Here we present empirical observations of hitherto undocumented, widespread and extensive methane ...
    • Widespread partial-depth hydrofractures in ice sheets driven by supraglacial streams 

      Chandler, David Matthew; Hubbard, Alun (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-19)
      Dramatic supraglacial lake drainage events in Greenland and Antarctica are enabled by rapid hydrofracture propagation through ice over 1 km thick. Here we present a slower mode of hydrofracture, where hairline surface fractures intersect supraglacial streams, and hypothesize that penetration depth is critically limited by water supply and englacial refreezing. We develop a model of stream-fed ...
    • Widespread subseafloor gas hydrate in the Barents Sea and Norwegian Margin 

      Cook, A.E.; Portnov, Alexey; Heber, R.C.; Vadakkepuliyambatta, Sunil; Bünz, Stefan (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-01)
      The distribution and concentration of subseafloor natural gas hydrate across margins is not well understood, because these systems are challenging to image and quantify remotely. Furthermore, it is unknown if shallow hydrate systems are linked to deeper oil and gas reservoirs. Herein, we analyze petroleum industry well logs with data in the gas hydrate stability zone and find that low concentrations ...
    • Wind at Northern Senja: Use of numerical weather prediction models for wind resource assessment 

      Hansen, Gjøran Emil (Master thesis; Mastergradsoppgave, 2020-12-15)
      Wind resource assessment for establishing decentralized power production in remote and complex areas, is challenging due to a lack of observational data. To overcome this problem, Numerical Weather Prediction (NWP) models can be used to provide data where no observations exist. This thesis uses NWP models to do a wind resource assessment at northern Senja. The power grid in the area is prone to ...
    • Wind Chill Effect & Thermal Insulation. Study of Wind Chill Effect and Thermal Insulation using Infrared Imaging 

      Ahmad, Tanveer (Master thesis; Mastergradsoppgave, 2017-05-15)
      Wind chill factor is explained as the cooling sensation due to the exposure of wind temperature environment. The wind chill factor depends on air temperature, wind velocity, and humidity. Wind chill poses serious health risks. Various wind chill index models are given in the literature. In order to understand the wind chill effect, it is important to understand the phenomenon of heat transfer. There ...
    • Wind Chill Effect in Cold Climate: Study of Wind Chill Effect Using Infrared Imaging 

      Ahmad, Tanveer (Research report; Forskningsrapport, 2016)
      Wind chill factor is explained as the cooling sensation due to the exposure of wind temperature environment. The wind chill factor depends on air temperature, wind velocity and humidity. Wind chill poses serious health risks. Various wind chill index models are given in literature. In order to understand the wind chill effect, it is important to understand the phenomenon of heat transfer. There are ...
    • Wind energy and economic assessment of a wind farm at Senja 

      Ørjavik, Ola Wang (Master thesis; Mastergradsoppgave, 2022-05-31)
      In order to deliver on the emission cuts in the Paris Agreement, additional renewable energy production is required to cover the rising energy demand. This thesis assesses the wind resources, energy production potential and the economic sustainability of a new potential wind farm, located at Senja island in northern Norway. The aim of this thesis is to decide if a new wind farm at Senja is an ...
    • Wind Energy at Nygårdsfjellet – Norway. Wind field characterization and modelling 

      Bilal, Muhammad (Doctoral thesis; Doktorgradsavhandling, 2016-11-25)
      The research focuses on the characterization of wind flow over complex terrain of Nygårdsfjell and numerical wind flow modelling. In the context to research focus, the main contributions of this research thesis are within the following areas: Characterization of wind flow at the Nygårdsfjell wind farm, situated in the arctic circle in Norway. Wind data is collected from the anemometers installed on ...
    • Wind power forecasting as input to day-ahead trading strategies for wind in complex terrain 

      Svane, Julie Therese (Master thesis; Mastergradsoppgave, 2022-06-01)
      Giving the increasing penetration of intermittent wind power in the liberalized electricity market, wind power forecasting (WPF) is a topic of growing importance [Kariniotakis, 2017]. The number of papers on the field WPF evaluating the statistical performance has increased rapidly, while only a proportion of the former studies focus on the economic benefit of WPF. In this study we have answered how ...
    • Wind Power Prediction with Machine Learning Methods in Complex Terrain Areas 

      Sæther, Brynhild Bentsen (Master thesis; Mastergradsoppgave, 2021-06-29)
      The increasing amount of intermittant wind energy sources connected to the power grid present several challenges in balancing the power network. Accurate prediction of wind power production is identified as one of the most important measures for balancing the power network while maintaining a sustainable integration of wind power in the power grid. However, the volatile nature of wind makes wind ...
    • Wind power predictions in complex terrain using analog ensembles 

      Birkelund, Yngve; Alessandrini, Stefano; Byrkjedal, Øyvind; Monache, Luca Delle (Journal article; Tidsskriftartikkel, 2018)
    • Wind redistribution of snow impacts the Ka- and Ku-band radar signatures of Arctic sea ice 

      Nandan, Vishnu; Willatt, Rosemary; Mallett, Robbie; Stroeve, Julienne; Geldsetzer, Torsten; Scharien, Randall; Tonboe, Rasmus; Yackel, John; Landy, Jack Christopher; Clemens-Sewall, David; Jutila, Arttu; Wagner, David N.; Krampe, Daniela; Huntemann, Marcus; Mahmud, Mallik; Jensen, David; Newman, Thomas; Hendricks, Stefan; Spreen, Gunnar; Macfarlane, Amy; Schneebeli, Martin; Mead, James; Ricker, Robert; Gallagher, Michael; Duguay, Claude; Raphael, Ian; Polashenski, Chris; Tsamados, Michel; Matero, Ilkka; Hoppmann, Mario (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-02)
      Wind-driven redistribution of snow on sea ice alters its topography and microstructure, yet the impact of these processes on radar signatures is poorly understood. Here, we examine the effects of snow redistribution over Arctic sea ice on radar waveforms and backscatter signatures obtained from a surface-based, fully polarimetric Ka- and Ku-band radar at incidence angles between 0∘ (nadir) and 50∘. ...
    • Wind resource assessment and siting for the expansion of Fakken wind park 

      Bjugg, Martine (Master thesis; Mastergradsoppgave, 2023-05-31)
      Norway is anticipated to experience an energy deficit in the coming years, and one solution to address this issue is the implementation of new renewable energy sources. To mitigate the projected energy deficit, increased energy production is required. With its considerable wind potential, the country offers ample opportunities for wind energy development. Consequently, there is a growing demand for ...
    • Wind resource assessment using mesoscale modelling. A case study at the potential wind farm site Rieppi 

      Blæsterdalen, Torgeir (Master thesis; Mastergradsoppgave, 2016-06-01)
      The growing wind power industry, increased occurrence of extreme weather, and the need for becoming independent of fossil fuels motivate the research on accurate simulation of near-surface wind. The aim of this study is wind resource assessment at the potential wind park site Rieppi, using two on-site measurement masts, simulations from the Weather Research and Forecasting (WRF) model, and ERA-Interim ...
    • Wind resource assessment using weather research and forecasting model. A case study of the wind resources at Havøygavlen wind farm 

      Fossem, Anders Aarhuus (Master thesis; Mastergradsoppgave, 2019-12-13)
      The need for energy increases globally due to rapid expansion of population and prosperity. To meet this demand while decreasing carbon emission and eventually transition out fossil fuel, efficient utilization of wind power is prominent. This study evaluates the performance of the Weather Research and Forecast model (WRF) with respect to wind speed and wind direction. The area of the study is ...
    • Wind speed and direction predictions by WRF and WindSim coupling over Nygårdsfjell 

      Bilal, Muhammad; Birkelund, Yngve; Solbakken, Kine (Journal article; Tidsskriftartikkel; Peer reviewed, 2016)
      In this study, the performance of the mesoscale meteorological Weather Research and Forecast (WRF) model coupled with the microscale computational fluid dynamics based model WindSim is investigated and compared to the performance of WRF alone. The two model set-ups, WRF and WRF-WindSim, have been tested on three high-wind events in February, June and October, over a complex terrain at the ...
    • Wind Turbine System Performance and Reliability Trend Analysis 

      Gebremichael, Michael (Master thesis; Mastergradsoppgave, 2022-01-30)
      This thesis project is a part of my master’s study course at the department of technology and safety. My thesis is focused on renewable energy, especially analyzing of energy production and technical performance of existing wind turbines within the arctic region. To that end it was important to contact local wind farm owners for operational data exchange. Using partners production and fault related ...
    • Winter storms accelerate the demise of sea ice in the Atlantic sector of the Arctic Ocean 

      Graham, Robert M.; Itkin, Polona; Meyer, Amelie; Sundfjord, Arild; Spreen, Gunnar; Smedsrud, Lars H.; Liston, Glen E.; Cheng, Bin; Cohen, Lana; Divine, Dmitry; Fer, Ilker; Fransson, Agneta; Gerland, Sebastian; Haapala, Jari; Hudson, Stephen R.; Johansson, Malin; King, Jennifer A.; Merkouriadi, Ioanna; Peterson, Algot Kristoffer; Provost, Christine; Randelhoff, Achim; Rinke, Annette; Rösel, Anja; Sennechael, Nathalie; Walden, Von P.; Duarte, Pedro; Assmy, Philipp; Steen, Harald; Granskog, Mats A. (Journal article; Peer reviewed, 2019-06-25)
      A large retreat of sea-ice in the ‘stormy’ Atlantic Sector of the Arctic Ocean has become evident through a series of record minima for the winter maximum sea-ice extent since 2015. Results from the Norwegian young sea ICE (N-ICE2015) expedition, a five-month-long (Jan-Jun) drifting ice station in first and second year pack-ice north of Svalbard, showcase how sea-ice in this region is frequently ...
    • Winter warmings, tides and planetary waves. Comparisions between CMAM (with interactive chemistry) and MFR-MetO observations and data. 

      Manson, A.H.; Hall, Chris; Meek, C.; Chshyolkova, T.; McLandress, C.; Avery, S.K.; Fritts, D.C.; Hocking, W.K.; Igarashi, K.; MacDougall, J.W.; Murayama, Y.; Riggin, D.C.; Thorsen, D.; Vincent, R.A. (Journal article; Peer reviewed; Tidsskriftartikkel, 2006-10-20)
      Following earlier comparisons using the Canadian Middle Atmosphere Model (CMAM, without interactive chemistry), the dynamical characteristics of the model are assessed with interactive chemistry activated. Time-sequences of temperatures and winds at Tromsø (70° N) show that the model has more frequent and earlier stratospheric winter warmings than typically observed. Wavelets at mesospheric heights ...