Mulige prosjekter til masteroppgaver

En kort presentasjon av veilederne finner du her.

Tracing sources of Nordic Seas overflow waters using Lagrangian modelling

Cold dense overflow waters exiting the Nordic Seas through deep gaps in the submarine ridge between Greenland and Scotland (Denmark Strait and the Faroe Bank Channel) are an important contribution to the lower limb of the Atlantic Meridional Overturning Circulation (AMOC). Some of these dense waters are produced locally in the Nordic Seas, but a part originates from the Arctic Ocean. The exact pathways and sources of these overflow waters, and their variability, are, however, not fully understood. This project will use Lagrangian trajectories in high-resolution ocean model simulations to backtrack overflow waters from Denmark Strait and the Faroe Bank Channel to determine their pathways, source regions, and water mass transformation. The project also includes comparing the model output to available observations.

The student should be interested in Polar oceanography and have a good background in programming, preferably python. 

Contact: Jakob Dörr, Stefanie Semper, Marius Årthun, Kjetil Våge

Wave model validation - implications for offshore design and activity

The accuracy of wave model hindcasts is crucial for offshore design such as offshore windparks and in general most offshore activity. Launched in October 2018, the CFOSAT(Chinese-French Oceanography Satellite) radar satellite mission has gathered unique observations of wave spectra opening for new unprecedented opportunities of comparingand analysing wave data over the entire globe. At the same time new wave hindcasts and cheap custom made wave buoys were developed (NORA3 wave hindcast, OpenMetBuoy,SFY-buoy, …) of which the quality in terms of wave spectra in the open ocean is not yet assessed thoroughly. Especially the NORA3 hindcast family has become the first choice for offshore design and wind energy and knowing its performance and accuracy is of high value to many stakeholders. The student will compare measurements from satellite and insitu buoys against state-of-the-art hindcasts. The quality and differences of each of the datasets will be assessed where the student will use and develop our in-house validation framework (https://github.com/bohlinger/wavy). The student should be interested in ocean waves and programming, preferably in python.

Contact: Patrik Bohlinger (MET), Øyvind Breivik (MET & GFI)

Exploring impacts of marine heatwaves on ship's biofouling

Sustainable shipping includes finding smart ways to reduce fuel consumption. Biofouling can be a problem in shipping, as it can lead to up to a 10-15% increase in fuel consumption. Biofouling is algae or other biological matter in the ocean attaching to vessel hull, and if continuing to grow, it can cause a drag effect that reduces the ship speed. Thus, to maintain a steady speed, the fuel consumption increases. Biofouling often seems to occur as a problem in warmer water and close to ports, where ship speed is low.

Marine heatwaves, i.e., extreme temperatures in the ocean, have become more frequent in the global ocean due to global warming. These extreme events can cover large areas and last up to several months. They are typically detected at the ocean surface but can also extend to deeper levels. Biofouling typically occurs at depths up to 25m depth and can happen within days.

The hypothesis for this project is that marine heatwaves can cause increases in fuel consumption, due to biofouling in coastal areas of the North Atlantic Ocean, where ships sail with low speed. The research will be exploratory, following two main tasks:

• Detect region and dates for marine heatwaves during 1991-2023 using daily ocean temperature data from a regional ocean model with 12km x 12km horizontal resolution, covering the North Atlantic and Arctic basins.
• Discuss possible impacts of increased sea temperature on biofouling in shipping based on existing literature.

Contact: Helene Langehaug (NERSC & GFI), Haiying Jia (NHH)

Occurrence of low-frequency waves in Norwegian waters

Low-frequency waves (infragravity waves, LF waves, mini-tsunamis) can be released in storm situations when the wave groups from the storm enter shallow water about 50-100 m. In deep water, the waves have a wave height of a few cm, with periods of 30-300 s, and wavelengths from 1000 m and upwards. Such very long waves can penetrate into areas that are protected from normal long wind-generated waves. They also have the ability to create movements in floating structures that would otherwise, thanks to their size, be largely unaffected by surface waves. The low-frequency waves have been documented and modeled when they are released along coasts with beaches and are reflected out into the open sea, but we do not know to what extent these are formed on the Norwegian shelf and whether the waves can continue inland into the fjords, since until now, no measurements have been made to investigate this. However, now a tidal station and several offshore stations have been logging at 1 Hz for a longer period, which makes it possible to analyze for LF waves, which will be the main focus for the work. The findings will be compared against wave model output to search for a relationship with the metocean conditions. 

Contact: Birgitte Furevik (MET & GFI)

What drives the fate of icebergs in the Arctic?

Being able to forecast the trajectory and decay of icebergs is an important issue both for safe navigation and fixed assets in the Arctic. Iceberg movements are driven by ocean currents, tides, winds, waves and sea ice motions, but which of these factors are the most important?

The master project will consist in testing an iceberg simulation module using high-quality forecasts of winds, currents and sea ice drift and comparing the simulations against icebergs tagged by the International Ice Patrol. The technical implementation of the iceberg model into the OpenDrift package is taken care of by researchers at NERSC and MET Norway. The work will consist in testing the respective contributions of tides, waves and sea ice on the trajectory and melting of icebergs.

The work will take place at NERSC, as part of the European funded project ACCIBERG, in collaboration with MET Norway and DMI, Denmark. The project will become the first freely available iceberg forecast, triggered on demand from a mobile phone.

The work can either be a 6-months full-time project from January to June 2024 or a more flexible arrangement finishing in June 2024. 

Contact: Lars H. Smedsrud or Laurent Bertino (NERSC)

Overturning in the Nordic Seas

We offer several topics for MSc projects in physical oceanography through the "Resilient northern overturning in a warming climate" group (ROVER). The overall objectives of the group are to better understand the ocean-atmosphere interaction that leads to dense-water formation in the Nordic Seas, with particular focus on the marginal ice zone along east Greenland, and its importance to the global overturning circulation. Suggested topics are 

• air-sea-ice interaction in the marginal ice zone east of Greenland
• water mass transformation in the Greenland and Iceland Seas
• boundary current dynamics

The approach will be to use a combination of shipborne and autonomous measurements as well as numerical models.

Contact: Kjetil Våge
 

Antarctic Polar oceanography

• Shelf break exchange in the Weddell Sea 

Why do warm water enter the continental shelf during summer but not in winter? The cross shelf break flow will be studied using results from laboratory experiments and/or numerical modelling supported by observations

• Hydrography near an ice shelf front

How does the hydrography near an ice shelf front change throughout the year / from year to year? The hydrography will be studied using moored instrumentation and CTD profiles

Contact: Elin Darelius  

Ocean Mixing Processes

We conduct observation-based research on ocean mixing processes. Typically data sets are already collected and available for analysis. But we also try to integrate students in research cruises for collecting their own data for a Master's study. 

• investigate the hydrography and mixing in fjords
• internal wave field properties inferred from moored observations near Yermak Plateau, Arctic Ocean
• eddies in the Norwegian Sea (using data collected under the PROVOLO project and NorEMSO)
• frontal processes across the Mohn Ridge inferred from shipboard and ocean lider observations (using data collected under the PROVOLO project and NorEMSO)

Contact: Ilker Fer 

Structure and variability of boundary currents observed by ocean gliders

Our ocean glider facility NorGliders has been operating gliders in the Nordic Seas. Some of these missions have concentrated on sampling the boundary current of warm Atlantic Water over the slopes off Norway and off Spitsbergen.  We offer Master's projects to study the structure, dynamics and variability of Atlantic Water currents at Svinøy and Gimsøy sections and in the West Spitsbergen Current

Contact: Ilker Fer 

Drivers of decadal variability in the Atlantic: role of wind stress

Climate predictions in the North Atlantic are especially promising on decadal timescales. However, what the major drivers of decadal variations in the North Atlantic is still uncertain. The atmosphere forces variability in the Atlantic, but is it only the heat fluxes or can the wind stress itself change the temperature and circulation in the North Atlantic Ocean on decadal timescales? 

Tasks: Analyze the Atlantic Ocean circulation in an experiment with the Norwegian earth system model (NorESM) where observed wind stress is prescribed to the ocean surface over the Atlantic, and compare the circulation with a fully coupled historical simulation with the same model. 

Contact: Lea Svendsen, Helene Asbjørnsen, Marius Årthun

Current-induced wave refraction along great circles and their impact on the wave height variability

Refraction of ocean waves due to near-surface currents causes areas with focusing and de-focusing of wave energy, which pose a severe threat for navigation at sea. This project aims on further developing a recently published open-source ray tracing model in Python by solving the governing equations in spherical coordinates, as well as including other relevant functionality. The code will be applied on already existing wave buoy observations in the Agulhas current to further understand the physics behind the observed wave height variability. The student should be familiar with Python programming.

Contact: Trygve Halsne (trygveh@met.no) and Øyvind Breivik

Lagrangian analysis of large scale North Atlantic dynamics

How are advection pathways affected by natural variability and abrupt changes in ocean circulation? Multiple lines of evidence suggest that the North Atlantic ocean may exhibit abrupt circulation changes. The characteristics and drivers of these changes pose a puzzle to the prediction of future changes in the North Atlantic. This project will investigate the pathways of the signals of abrupt decadal events using Lagrangian analysis of general ocean circulation models. The aim is to investigate and create an understanding for the physical processes involved. The project is part of the Bjerknes strategic project DYNASOR which aims to clarify how currents and other features of the North Atlantic Ocean interact. Fundamental programming knowledge is necessary; however, ample supervision and support will be provided.

Contact: Andreas Born, Helene Asbjørnsen, Ina Nagler

High-frequency variability in the northwestern Iceland Sea

The northwestern Iceland Sea has not been studied much previously due to the lack of wintertime measurements. Only with the recent retreat of sea ice toward Greenland, this area has become more accessible. A mooring that was deployed in the northwestern Iceland Sea returned two-year long time series of temperature with a temporal resolution of up to 30 s. This unique data set will be used to investigate small-scale processes and high-frequency variability in the upper water column.

Contact: Stefanie Semper, Ilker Fer, and Kjetil Våge

Klimatrender i kyst og fjordstrøk

Kombinere målinger fra Hardangerfjorden og faste overvåkningsstasjoner på kysten med NorKyst800, modellarkiv med 800m oppløsning langs hele norskekysten 1995-2020, for å identifisere endringer i det fysiske miljøet og mulige konsekvenser for fjordøkosystemene.

Kontaktperson: Mari Myksvoll (mari.myksvoll@hi.no)

Spredning av lakselus langs norskekysten

Kjøre partikkelspredningsmodell for lakselus langs hele norskekysten med det eksisterende modellarkivet NorKyst800 (1995-2020) for å kartlegge innstrømningsepisoder i ulike fjordsystemer, og diskuterer hvordan det fysiske miljøet påvirker bæreevnen for akvakultur i produksjonsområdene.

Kontaktperson: Mari Myksvoll (mari.myksvoll@hi.no)

Arctic Polar Oceanography and sea ice

We offer topics on the longer term changes and variability of sea ice and oceanography in the Arctic Ocean, using a mix of climate models, process models,and observations. The existing climate model simulations, through cooperation with the Climate group using the Norwegian Earth System Model (NorESM), can be used for evaluation and analysis.

• Barents Sea Ice Cover variability the last 450 years
• Rapid Ice Loss events in NorESM simulations

Contact: Lars Henrik Smedsrud 

Stormflo i Sognefjorden

Sjøkartverket har en unik måleserie av vannstand på flere posisjoner i Sognefjorden. Målingene begynte i juli 2018, og pågår fremdeles. Det betyr at disse måleseriene dekker de to store stormflo episodene vi hadde i vinter 2019-2020, og vil gi ny innsikt i hvordan vannstand i Sognefjorden varierer med forskjellige pådrag fra atmosfære, tidevann og ferskvannsavrenning. Havforskingen har også strømmålere ute som dekker de samme episodene, og disse dataene vil være tilgjengelige for en Master student. Havforskingen kan også hjelpe til med modelleringsdata. Studenten får dermed tilgang til veiledning fra to av våre institusjoner som ansetter mange oseanografer: Sjøkartverket og Havforskingsinstituttet.

Kontakt på GFI: Elin Darelius

A wave energy climatology for Norwegian waters.

The wave energy flux is the relevant quantity for estimating the potential for wave energy production. Using the 10-km resolution hindcast archive NORA10 which spans the period 1957 to present, the student will investigate the wave energy potential in Norwegian waters. The NORA10  archive was developed and is maintained by the Norwegian Meteorological Institute and is the authoritative reference data set for historical wind and wave climate in the Norwegian Sea, the North Sea and the BarentsSea.  

Supervisor: Øyvind Breivik (oyvind.breivik@met.no)

Wave effects in the upper ocean.

The ocean surface boundary layer is influenced by the presence of surface waves. The waves affect the ocean through wave breaking, modification of the momentum flux from the atmosphere (wind stress) and through the Stokes drift, a second-order wave effect that causes material transport. The NEMO model has recently been set up on a regional scale and can be used to quantify the impact of the wave field on a high-resolution ocean model. Relevant questions are how the upwelling and the mixing is affected by waves in the North Sea. Good coding skills are required.

Supervisors: Øyvind Breivik (oyvind.breivik@met.no) and Lichuan Wu   (SMHI)

Geophysical modelling of real oil spills in the Gulf of Mexico.

A generic, open source, ocean trajectory framework (OpenDrift - https://opendrift.github.io/) has been developed at the Norwegian Meteorological Institute. Through partners in Florida we have obtained satellite observations (shape files) describing the development of a real spill from the Taylor pipeline in the Gulf of Mexico over several days. Ocean surface drifter data from the region are also available. A master student is sought to run experiments with the Open Oil module using various parameterizations and to compare with observations for analysis. Forcing will be provided from a high resolution ocean model and atmospheric and wave models from the European Center for Medium Range Weather Forecasting (ECMWF). The project will involve collaboration with the University in Miami and other US partners. The student should be confident in Python programming.

Supervisors: Lars Robert Hole (lrh@met.no) and Øyvind Breivik (oyvind.breivik@met.no)

Storm surge modeling in Vietnam using ROMS and analytical models.

The Norwegian Meteorological Institute (MET Norway) collaborates with the National Hydro-Meteorological Service of Vietnam (NHMS) on a capacity building project sponsored by the Norwegian government. The main purpose of the project is geohazard disaster prevention. NHMS has upgraded their ocean model system to the Regional Ocean Models System (ROMS) (http://myroms.org). MET Norway uses ROMS in a nested configuration from 20km (entire Arctic Ocean) to 4km to 800m(the Norwegian coast). This model system also acts as input for the oil drift and search and rescue models. In this master project we propose to use a simple 2D setup of ROMS and compare with tidal observation in Vietnam. Vietnam currently has 17 operational tidal stations with hourly or 6 hourly observations. The data can also be compared with analytical formulas. The work will involve numerical simulations and statistical analysis. The student will collaborate with scientists at MET Norway and NHMS and can also expect to travel to Vietnam.

Supervisor: Lars R. Hole (lrh@met.no) and Øyvind Breivik (oyvind.breivik@met.no)