| 1. |
- Amir Heidari, Payam, 1989, et al.
(författare)
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A state-of-the-art model for spatial and stochastic oil spill risk assessment: A case study of oil spill from a shipwreck
- 2019
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Ingår i: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 126, s. 309-320
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Tidskriftsartikel (refereegranskat)abstract
- Oil spills are serious environmental issues that potentially can cause adverse effects on marine ecosystems. In some marine areas, like the Baltic Sea, there is a large number of wrecks from the first half of the 20th century, and recent monitoring and field work have revealed release of oil from some of these wrecks. The risk posed by a wreck is governed by its condition, hazardous substances contained in the wreck and the state of the surrounding environment. Therefore, there is a need for a common standard method for estimating the risks associated with different wrecks. In this work a state-of-the-art model is presented for spatial and stochastic risk assessment of oil spills from wrecks, enabling a structured approach to include the complex factors affecting the risk values. A unique feature of this model is its specific focus on uncertainty, facilitating probabilistic calculation of the total risk as the integral expected sum of many possible consequences. A case study is performed in Kattegat at the entrance region to the Baltic Sea to map the risk from a wreck near Sweden. The developed model can be used for oil spill risk assessment in the marine environment all over the world.
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| 2. |
- Axell, Cecilia, 1965-, et al.
(författare)
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Teacher Students’ Critical Thinking Skills Using the Concept of Disruptive Technologies
- 2018
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Ingår i: 2018 PATT36 International Conference. - : Technology Education Research Group. - 9781527225077 - 9781527225084 ; , s. 239-245
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Critical thinking is fundamental to 21st century learning and has thus become an important part of the technology curricula in many countries. Critical thinking draws on the ability to examine, analyse, interpret and evaluate, as well as asking questions and participating in discussions about risks and benefits of different technological solutions. An important task for teachers is to support young children in developing these skills. Students on a Swedish primary school teacher education programme were given an assignment inspired by the concept of ‘disruptive technologies’ (Barlex, Givens & Steeg, 2016; Manyika, Chui, Bughin, Dobbs, Bisson & Marrs, 2013), choosing from one of nine disruptive technologies and searching for information. The list was created on the grounds that these are technologies that are likely to have a significant effect on the students’ lives in a not too distant future. Based on the information found, the students were to critically analyse the technology they had chosen. This case study was performed through a thematic analysis of 120 assignment texts. The analysis showed that some of the suggested technologies were chosen more often than others. Autonomous cars came top, although robots in elderly care were the most frequently chosen technology among female students. The students performed well in the searching and collecting process. They found information about pros and cons for their chosen disruptive technology. However, the analysis also showed that the students had difficulty evaluating and problematising the information they had found. In their conclusions they did not change their original point of view. Even though they found more negative aspects of a new technology, they accentuated the positives.
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| 3. |
- Berg, Anders, 1983, et al.
(författare)
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Comparison between SAR derived sea ice displacement and hindcasts by the operational ocean model HIROMB
- 2013
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Ingår i: Proceedings of the IEEE International Geoscience and Remote Sensing Symposium (IGARSS), Melbourne, Australia, July 21-26, 2013. - 9781479911141 ; , s. 3630-3633
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Konferensbidrag (refereegranskat)abstract
- The purpose of this paper is to compare measurements of sea ice displacement from SAR imagery with ice floe drift trajectories modeled by the operational ocean circulation model HIROMB. The study examines the ice movement in the Fram Strait during a two-week period in April, 2011. The results indicate that the HIROMB model overestimates the drift speed by a factor 1 - 2.5, which may be attributed to an underestimated thickness of the ice. The model data also exhibit a directional offset in the positive clockwise direction of 10 - 30 degrees over the whole study region. The results of this study may be used to direct the model development and improve the model initialization.
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| 4. |
- Elyouncha, Anis, 1978, et al.
(författare)
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Joint retrieval of ocean surface wind and current vectors from satellite SAR data using a Bayesian inversion method
- 2021
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Ingår i: Remote Sensing of Environment. - : Elsevier BV. - 0034-4257. ; 260
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a method for joint retrieval of the ocean surface wind and current vectors using the backscatter and the Doppler frequency shift measured by spaceborne single-beam single-polarization synthetic aperture radar (SAR). The retrieval method is based on the Bayesian approach with the a priori information provided by atmospheric and oceanic models for surface wind and currents, respectively. The backscatter and Doppler frequency shift are estimated from the along-track interferometric SAR system TanDEM-X data. The retrieval results are compared against in-situ measurements along the Swedish west coast. It is found that the wind retrieval reduces the atmospheric model bias compared to in-situ measurements by about 1 m/s for wind speed, while the bias reduction in the wind direction is minor as the wind direction provided by the model was accurate in the studied cases. The ocean model bias compared to in-situ measurements is reduced by about 0.04 m/s and 12 circle for current speed and direction, respectively. It is shown that blending SAR data with model data is particularly useful in complex situations such as atmospheric and oceanic fronts. This is demonstrated through two case studies in the Skagerrak Sea along the Swedish west coast. It is shown that the retrieval successfully introduces small scale circulation features detected by SAR that are unresolved by the models and preserves the large scale circulation imposed by the models.
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| 5. |
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| 6. |
- Hordoir, Robinson, et al.
(författare)
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Nemo-Nordic 1.0 : a NEMO-based ocean model for the Baltic and North seas - research and operational applications
- 2019
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Ingår i: Geoscientific Model Development. - : Copernicus GmbH. - 1991-959X .- 1991-9603. ; 12:1, s. 363-386
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Tidskriftsartikel (refereegranskat)abstract
- We present Nemo-Nordic, a Baltic and North Sea model based on the NEMO ocean engine. Surrounded by highly industrialized countries, the Baltic and North seas and their assets associated with shipping, fishing and tourism are vulnerable to anthropogenic pressure and climate change. Ocean models providing reliable forecasts and enabling climatic studies are important tools for the shipping infrastructure and to get a better understanding of the effects of climate change on the marine ecosystems. Nemo-Nordic is intended to be a tool for both short-term and long-term simulations and to be used for ocean forecasting as well as process and climatic studies. Here, the scientific and technical choices within Nemo-Nordic are introduced, and the reasons behind the design of the model and its domain and the inclusion of the two seas are explained. The model's ability to represent barotropic and baroclinic dynamics, as well as the vertical structure of the water column, is presented. Biases are shown and discussed. The short-term capabilities of the model are presented, especially its capabilities to represent sea level on an hourly timescale with a high degree of accuracy. We also show that the model can represent longer timescales, with a focus on the major Baltic inflows and the variability in deep-water salinity in the Baltic Sea.
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| 7. |
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| 8. |
- Liu, Ye, et al.
(författare)
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Reanalyzing temperature and salinity on decadal time scales using the ensemble optimal interpolation data assimilation method and a 3D ocean circulation model of the Baltic Sea
- 2013
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Ingår i: Journal Of Geophysical Research: Oceans. - : American Geophysical Union (AGU). - 2169-9275. ; 118:10, s. 5536-5554
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Tidskriftsartikel (refereegranskat)abstract
- A 30-year (1970-1999) reanalysis of temperature and salinity is conducted by assimilating temperature and salinity profiles into an ocean model of the Baltic Sea with ensemble optimal interpolation approach. Some configurations of the reanalysis are presented. For example, the samples are chosen from the same season as the analysis time to address the strong seasonal variability. The impact of different observation time windows on the analysis results is also discussed. A locally determined alpha is adopted for the long-time-scale simulation. To assess the accuracy of the reanalysis, a set of comparisons between the reanalysis results and the free run results was performed. The root mean square deviations (RMSDs) between the reanalysis results and not-yet-assimilated observations at all levels show that, compared to the free run, temperature and salinity have been improved significantly, that is, by 31.1 and 38.8%, respectively. The vertical structure of the reanalyzed fields is also adjusted. The reanalysis results show that the improvements in both temperature and salinity are smaller at greater water depths. Comparison with independent CTD data, the reanalysis significantly improved temperatures and salinities in all layers relative to the free run. For temperature and salinity during the period of ship voyages, the RMSDs are reduced by 32.9 and 25.5%, respectively. The temporal variations of the deep-water salinity caused by saltwater inflows are better captured by the reanalysis than by the free run. Moreover, the reanalysis improved the estimation of the depth of the halocline and thermocline, which are overestimated in the simulation without data assimilation.
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| 9. |
- Nilsson, Erik O., 1983-, et al.
(författare)
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Characterization of Wave Energy Potential for the Baltic Sea with Focus on the Swedish Exclusive Economic Zone
- 2019
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Ingår i: Energies. - : MDPI AG. - 1996-1073. ; 12:5
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Tidskriftsartikel (refereegranskat)abstract
- In this study, a third-generation wave model is used to examine the wave power resource for the Baltic Sea region at an unprecedented one-kilometer-scale resolution for the years 1998 to 2013. Special focus is given to the evaluation and description of wave field characteristics for the Swedish Exclusive Economic Zone (SEEZ). It is carried out to provide a more detailed assessment of the potential of waves as a renewable energy resource for the region. The wave energy potential is largely controlled by the distance from the coast and the fetch associated with the prevailing dominant wave direction. The ice cover is also shown to significantly influence the wave power resource, especially in the most northern basins of the SEEZ. For the areas in focus here, the potential annual average wave energy flux reaches 45 MWh/m/year in the two sub-basins with the highest wave energies, but local variations are up to 65 MWh/m/year. The assessment provides the basis for a further detailed identification of potential sites for wave energy converters. An outlook is given for additional aspects studied within a broad multi-disciplinary project to assess the conditions for offshore wave energy conversion within the SEEZ.
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