49 research outputs found
Warming of the polar water layer in Disko Bay and potential impact on Jakobshavn Isbrae
No full textA number of recent studies have shown enhanced retreat of tidewater glaciers over much of southern and western Greenland. One of the fastest retreats has occurred at Jakobshavn Isbrae, with the rapid retreat linked to the arrival of relatively warm and saline Irminger water along the west coast of Greenland. Similar links to changes in ocean water masses on the coastal shelf of Greenland were also seen on the east coast. This study presents hydrographic data from Disko Bay, additionally revealing that there was also a significant warming of the cold polar water entering Disko Bay from the mid-to-late 1990s onward. This layer, which lies at a depth of ~30–200 m, warmed by 1°–2°C. The heat content of the polar water layer increased by a factor of 3.6 for the post-1997 period compared to the period prior to 1990. The heat content in the west Greenland Irminger water layer between the same periods increased only by a factor of 2, but contained more total heat. The authors suggest that the changes in the polar water layer are related to circulation changes in Baffin Bay
Drivers for Atlantic-origin waters abutting Greenland
No full textThe oceanic heat available in Greenland’s troughs is dependent on the geographic location of the trough, the water origin, and how the water is impacted by local processes along the pathway to the trough. This study investigates the spatial pattern and quantity of the warm water (with a temperature greater −1.5◦C) brought to the shelf and into the troughs abutting the Greenland Ice Sheet (GrIS). An increase in ocean heat in these troughs may drive a retreat of the GrIS. Warm water that is exchanged from the trough into the fjord may influence the melt on the marine-terminating glaciers. Several regional ocean model experiments were used to study regional differences in heat transport through troughs. Results showed that warm water extends north into Baffin Bay, reaching as far north as the Melville Bay troughs. Melville Bay troughs experienced warming following 2009. From 2004 to 2006, model experiments captured an increase in onshore heat flux in the Disko Bay trough, coinciding with the timing of the disintegration of Jakobshavn Isbrae’s floating tongue and observed ocean heat increase in Disko Bay. The seasonality of the maximum onshore heat flux differs due to distance away from the Irminger Sea. Ocean temperatures near the northwestern coast and southeastern coast respond differently to changes in meltwater from Greenland and high-frequency atmospheric phenomena. With a doubling of the GrIS meltwater, Baffin Bay troughs transported ∼ 20 % more heat towards the coast. Fewer storms resulted in a doubling of onshore heat through Helheim Glacier’s trough. These results demonstrate the regional variability of onshore heat transport through troughs and its potential implications to the GrIS
The Role of the Real: Authenticity in Fictional Travel Literature and the Contemporary Modus Operandi
No full textThis thesis explores how fictional travel writing produces and conveys authenticity and the inherent capabilities of authenticity in social and cultural critique. The focus pertains to contemporary travel writing, ensuring a prevalent understanding of current tendencies and innovations. Qualitative Content Analysis and traditional textual analysis are employed to confirm the specific modes of authenticity, as shown in the three novels The White Mary (2008), Heroes of the Frontier (2016) and Memorial (2020). The analysis reveals that authenticity is conveyed following the specific narrative of the novels. This was found to be present in two separate entities of authenticity. Firstly, the thesis finds that authenticity can be presented as a literary device in which the author can convey and write authentic perspectives to conduct a plausible narrative. Secondly, the thesis finds that the novels also represent an external authenticity related to contextual elements, such as authorship, lingering zeitgeist, and culture. To entrench the analysis in a contemporary perspective, the thesis aligns the functions of authenticity with those of New Sincerity, proposing an overlap of concepts. This creates an opportunity to study the current state of the genre and the future direction of literary travel writing. The accumulated findings of the analysis showcase that the genre has moved away from literary conventions placed within postmodernity, instead having moved towards a new literary modus operandi. This means that the state of the genre has shifted its general tendencies of conduct. The proposed interpretative mode interplays with the defined structures of New Sincerity. This means that the novels analysed showcase a disposition in which their narratives tend to engage with interpersonal propositions between the author and the readership. Furthermore, the narratives contain a combination of experimental structures and well-established genre tropes. The concord relegates a new function in fictional travel writing, related to New Sincerity. The research conducted in this thesis contributes to understanding the contemporary state of fictional travel writing and the integral role of authenticity. By illuminating the understanding of authenticity in fictional travel writing, the thesis lays the groundwork for further research into the intrinsic relationship between authenticity and Cultural Critique. <br/
Ecosystem variability in west Greenland waters
No full textA review of the climate conditions off West Greenland during the past 50 years shows large variability in the atmospheric, oceanographic and sea-ice variables, as well as in fish stocks. A positive relationship is found between water temperature and the recruitment of cod and redfish, whereas the recruitment of shrimp and halibut is negatively related to temperature. Observed shifts in the hydrographic conditions during the second half of the 1990s indicate that some changes in the environment may be expected in the coming years. Relationships between the past variations in fish resources, hydrographic conditions, and the large-scale climatic conditions, as expressed by the North Atlantic Oscillation (NAO), strongly support the incorporation of environmental variability into prediction models for fish recruitment and therefore into the assessment of the fish resources
Larval drift and settling of Greenland halibut (R. hippoglossoides Walbaum) in Northwest Atlantic with special focus on Greenlandic waters
No full textArctic PASSION - High Resolution Synthetic Aperture Radar based Risk Index Outcome (AP-RIO)
No full textThe Risk Index Outcome (RIO) is a critical component of the Polar Operational Limit Assessment Risk Indexing System (POLARIS) developed by the International Maritime Organization (IMO, 2016). RIO evaluates the operational risks for ships navigating in ice-infested waters by evaluating ice conditions and offers a quantifiable measure of risk that aids in decision-making for safe navigation in polar regions based on ship ice class, sea ice type/stage of development (SOD) and sea ice concentration (SIC). The DMI-led Automated Sea Ice Products (DMI-ASIP; Wulf et al., 2024, dataset) provides daily maps of SOD and SIC based on Sentinel-1 SAR imagery, AMSR-2 Passive Microwave and Ice Charts from the Greenland and Canadian Ice Services, combined with novel AI retrieval and processing techniques. In the framework of EU funded Arctic PASSION project, we produced 10 years of satellite observation based weekly RIO maps referred as the Arctic PASSION-RIO (AP-RIO) by leveraging DMI-ASIP datasets. The AP-RIO dataset will provide weekly risk assessment maps for the given ship classes and will support the establishment of a 10 year climatology thereby enabling the assessment of RIO variability in the years covered by the input DMI-ASIP products. The AP-RIO dataset will enhance the safety and efficiency of maritime operations in the polar seas, providing a robust reference for evaluating normal and extreme ice conditions. AP-RIO is produced in the framework of the Arctic PASSION project (European Union's Horizon 2020 research and innovation program under grant agreement No. 101003472) and supported by the DMI-ASIP development team.
Algorithm and Processing Scheme:
SIC and SOD from ASIP are processed (by taking the mean and mode respectively) into a weekly field based on the daily files for that week. This is done for the time period of 3 Oct. 2014 - 3 Oct. 2024. The weekly SOD is used to find the Risk Value (RV) by looking at the lookup table (Dybkjær et al. 2025a). Risk Index Outcome (RIO) values are computed for each pixel in the field based on the RIO formula (RIO = SIC x RV) using the SIC from ASIP and the found RV. The meaning of the computed RIO values can be interpreted using the table in (Dybkjær et al. 2025b). The RIO field is finally saved to weekly NetCDF files
The sensitivity of primary productivity in Disko Bay, a coastal Arctic ecosystem, to changes in freshwater discharge and sea ice cover
No full textThe Greenland ice sheet is melting, and the rate of ice loss has increased 6-fold since the 1980s. At the same time, the Arctic sea ice extent is decreasing. Meltwater runoff and sea ice reduction both influence light and nutrient availability in the coastal ocean, with implications for the timing, distribution, and magnitude of phytoplankton production. However, the integrated effect of both glacial and sea ice melt is highly variable in time and space, making it challenging to quantify. In this study, we evaluate the relative importance of these processes for the primary productivity of Disko Bay, west Greenland, one of the most important areas for biodiversity and fisheries around Greenland. We use a high-resolution 3D coupled hydrodynamic-biogeochemical model for 2004-2018 validated against in situ observations and remote sensing products. The model-estimated net primary production (NPP) varied between 90-147 C m-2 yr-1 during 2004-2018, a period with variable freshwater discharges and sea ice cover. NPP correlated negatively with sea ice cover and positively with freshwater discharge. Freshwater discharge had a strong local effect within ∼25 km of the source-sustaining productive hot spots during summer. When considering the annual NPP at bay scale, sea ice cover was the most important controlling factor. In scenarios with no sea ice in spring, the model predicted a ∼30% increase in annual production compared to a situation with high sea ice cover. Our study indicates that decreasing ice cover and more freshwater discharge can work synergistically and will likely increase primary productivity of the coastal ocean around Greenland
Recent increases in Arctic freshwater flux affects Labrador Sea convection and Atlantic overturning circulation
No full textThe Atlantic Meridional Overturning Circulation (AMOC) is an important component of ocean thermohaline circulation. Melting of Greenland’s ice sheet is freshening the North Atlantic; however, whether the augmented freshwater flux is disrupting the AMOC is unclear. Dense Labrador Sea Water (LSW), formed by winter cooling of saline North Atlantic water and subsequent convection, is a key component of the deep southward return flow of the AMOC. Although LSW formation recently decreased, it also reached historically high values in the mid-1990s, making the connection to the freshwater flux unclear. Here we derive a new estimate of the recent freshwater flux from Greenland using updated GRACE satellite data, present new flux estimates for heat and salt from the North Atlantic into the Labrador Sea and explain recent variations in LSW formation. We suggest that changes in LSW can be directly linked to recent freshening, and suggest a possible link to AMOC weakening
Modelling the ocean circulation on the West Greenland shelf with special emphasis on northern shrimp recruitment
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