| 1. |
- Bensi, M., et al.
(författare)
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Deep flow variability offshore south-west Svalbard (fram strait)
- 2019
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Ingår i: Water. - : MDPI AG. - 2073-4441. ; 11:4
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Tidskriftsartikel (refereegranskat)abstract
- - Water mass generation and mixing in the eastern Fram Strait are strongly influenced by the interaction between Atlantic and Arctic waters and by the local atmospheric forcing, which produce dense water that substantially contributes to maintaining the global thermohaline circulation. The West Spitsbergen margin is an ideal area to study such processes. Hence, in order to investigate the deep flow variability on short-term, seasonal, and multiannual timescales, two moorings were deployed at ~1040 m depth on the southwest Spitsbergen continental slope. We present and discuss time series data collected between June 2014 and June 2016. They reveal thermohaline and current fluctuations that were largest from October to April, when the deep layer, typically occupied by Norwegian Sea Deep Water, was perturbed by sporadic intrusions of warmer, saltier, and less dense water. Surprisingly, the observed anomalies occurred quasi-simultaneously at both sites, despite their distance (~170 km). We argue that these anomalies may arise mainly by the effect of topographically trapped waves excited and modulated by atmospheric forcing. Propagation of internal waves causes a change in the vertical distribution of the Atlantic water, which can reach deep layers. During such events, strong currents typically precede thermohaline variations without significant changes in turbidity. However, turbidity increases during April-June in concomitance with enhanced downslope currents. Since prolonged injections of warm water within the deep layer could lead to a progressive reduction of the density of the abyssal water moving toward the Arctic Ocean, understanding the interplay between shelf, slope, and deep waters along the west Spitsbergen margin could be crucial for making projections on future changes in the global thermohaline circulation. © 2019 by the authors.
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| 2. |
- Dotto, T. S., et al.
(författare)
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Wind-Driven Processes Controlling Oceanic Heat Delivery to the Amundsen Sea, Antarctica
- 2019
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Ingår i: Journal of Physical Oceanography. - : American Meteorological Society. - 0022-3670 .- 1520-0485. ; 49:11, s. 2829-2849
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Tidskriftsartikel (refereegranskat)abstract
- Variability in the heat delivery by Circumpolar Deep Water (CDW) is responsible for modulating the basal melting of the Amundsen Sea ice shelves. However, the mechanisms controlling the CDW inflow to the region's continental shelf remain little understood. Here, a high-resolution regional model is used to assess the processes governing heat delivery to the Amundsen Sea. The key mechanisms are identified by decomposing CDW temperature variability into two components associated with 1) changes in the depth of isopycnals [heave (HVE)], and 2) changes in the temperature of isopycnals [water mass property changes (WMP)]. In the Dotson-Getz trough, CDW temperature variability is primarily associated with WMP. The deeper thermocline and shallower shelf break hinder CDW access to that trough, and CDW inflow is regulated by the uplift of isopycnals at the shelf break-which is itself controlled by wind-driven variations in the speed of an undercurrent flowing eastward along the continental slope. In contrast, CDW temperature variability in the Pine Island-Thwaites trough is mainly linked to HVE. The shallower thermocline and deeper shelf break there permit CDW to persistently access the continental shelf. CDW temperature in the area responds to wind-driven modulation of the water mass on-shelf volume by changes in the rate of inflow across the shelf break and in Ekman pumping-induced vertical displacement of isopycnals within the shelf. The western and eastern Amundsen Sea thus represent distinct regimes, in which wind forcing governs CDW-mediated heat delivery via different dynamics.
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| 3. |
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| 4. |
- Hernandez-Molina, F. J., et al.
(författare)
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Oceanographic processes and morphosedimentary products along the Iberian margins: A new multidisciplinary approach
- 2016
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Ingår i: Marine Geology. - : Elsevier BV. - 0025-3227. ; 378, s. 127-156
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Tidskriftsartikel (refereegranskat)abstract
- Our understanding of bottom-currents and associated oceanographic processes (e.g., overflows, barotropic tidal currents) including intermittent processes (e.g., vertical eddies, deep sea storms, horizontal vortices, internal waves and tsunamis) is rapidly evolving. Many deep-water processes remain poorly understood due to limited direct observations, but can generate significant depositional and erosional features on both short and long term time scales. This paper represents a review work, which describes for the first time these oceanographic processes and examines their potential role in the sedimentary features along the Iberian continental margins. This review explores the implications of the studied processes, given their secondary role relative to other factors such as mass-transport and turbiditic processes, and highlights three major results: a) contourite depositional and erosional features are ubiquitous along the margins, indicating that bottom currents and associated oceanographic processes control the physiography and sedimentation; b) the position of interfaces between major water masses and their vertical and spatial variation in time specifically appears to exert primary control in determining major morphologic changes along the slope gradient, including the contourite terraces development; and c) contourites deposits exhibit greater variation than the established fades model suggests. Therefore, a consistent facies model however faces substantial challenges in terms of the wide range of oceanographic processes that can influence in their development. An integrated interpretation of these oceanographic processes requires an understanding of contourites, seafloor features, their spatial and temporal evolution, and the near-bottom flows that form them. This approach will synthesize oceanographic data, seafloor morphology, sediments and seismic images to improve our knowledge of permanent and intermittent processes around Iberia, and evaluate their conceptual and regional role in the margin's sedimentary evolution. Given their complexes, three-dimensional and temporally-variable nature, integration of these processes into sedimentary, oceanographic and climatological frameworks will require a multidisciplinary approach that includes Geology, Physical oceanography, Paleoceanography and Benthic Biology.
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| 5. |
- Hernandez Molina, Javier, et al.
(författare)
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Oceanographic processes and products around the Iberian margin: a new multidisciplinary approach : Procesos oceanográficos y sus productos alrededor del margen de Iberia: una nueva aproximación multidisciplinar
- 2015
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Ingår i: Boletín Geológico y Minero. - 0366-0176 .- 0366-0176. ; 126:2-3, s. 279-326
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Tidskriftsartikel (refereegranskat)abstract
- Our understanding of the role of bottom-current and associated oceanographic processes (as overflows, barotropic currents, tides or intermittent processes like giant vertical eddies, deep sea storms, horizontal vortices, internal waves and tsunamis) is rapidly improving. But, most of these oceanographic deep-water processes remains poorly understood and have been rarely observed but believed to be capable of generating depositional and erosional features in many contexts at both short and long term. In present compilation we described these oceanographic processes including examples or their potential role in the sedimentation processes around the Iberia margin. Importance of these processes is highlighted and its implication discussed to demonstrate that these oceanographic processes are very important is affecting the shape and evolution of the Iberian continental margin and adjacent oceanic basins although is not still considered as important as other factors as mass-transport deposits and turbiditic processes. To have a better understanding on the implication of all these oceanographic processes connections have to be made between (contourite) sea-floor features, their spatial and temporal evolution, and the near-bottom flows that form them. The only way to achieve that in next decades is by a more intensive collaboration between specialist from Geology, Oceanography and Benthic Biology in new multi-disciplinary studies. Consequently, further multi-disciplinary approach uses oceanographic data, sea-floor morphology, sediments and seismic characterization will be essential for improve our knowledge of these permanent and intermittent processes around Iberia and evaluate their conceptual and regional role in the margins evolution over time and space.
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| 6. |
- Ketzel, M., et al.
(författare)
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Estimation and validation of PM2.5/PM10 exhaust and non-exhaust emission factors for practical street pollution modelling
- 2007
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Ingår i: Atmos. Environ.. - : Elsevier BV. ; 41, s. 9370-9385
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Tidskriftsartikel (refereegranskat)abstract
- In order to carry out efficient traffic and air quality management, validated models and PM emission estimates are needed. This paper compares current available emission factor estimates for PM10 and PM2.5 from emission databases and different emission models, and validates these against eight high quality street pollution measurements in Denmark, Sweden, Germany, Finland and Austria.The data sets show large variation of the PM concentration and emission factors with season and with location. Consistently at all roads the PM10 and PM2.5 emission factors are lower in the summer month than the rest of the year. For example, PM10 emission factors are in average 5–45% lower during the month 6–10 compared to the annual average.The range of observed total emission factors (including non-exhaust emissions) for the different sites during summer conditions are 80–130 mg km−1 for PM10, 30–60 mg km−1 for PM2.5 and 20–50 mg km−1 for the exhaust emissions.We present two different strategies regarding modelling of PM emissions: (1) For Nordic conditions with strong seasonal variations due to studded tyres and the use of sand/salt as anti-skid treatment a time varying emission model is needed. An empirical model accounting for these Nordic conditions was previously developed in Sweden. (2) For other roads with a less pronounced seasonal variation (e.g. in Denmark, Germany, Austria) methods using a constant emission factor maybe appropriate. Two models are presented here.Further, we apply the different emission models to data sets outside the original countries. For example, we apply the “Swedish” model for two streets without studded tyre usage and the “German” model for Nordic data sets. The “Swedish” empirical model performs best for streets with studded tyre use, but was not able to improve the correlation versus measurements in comparison to using constant emission factors for the Danish side. The “German” method performed well for the streets without clear seasonal variation and reproduces the summer conditions for streets with pronounced seasonal variation. However, the seasonal variation of PM emission factors can be important even for countries not using studded tyres, e.g. in areas with cold weather and snow events using sand and de-icing materials. Here a constant emission factor probably will under-estimate the 90-percentiles and therefore a time varying emission model need to be used or developed for such areas.All emission factor models consistently indicate that a large part (about 50–85% depending on the location) of the total PM10 emissions originates from non-exhaust emissions. This implies that reduction measures for the exhaust part of the vehicle emissions will only have a limited effect on ambient PM10 levels.
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| 7. |
- Kim, T. W., et al.
(författare)
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Interannual Variation of Modified Circumpolar Deep Water in the Dotson-Getz Trough, West Antarctica
- 2021
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Ingår i: Journal of Geophysical Research: Oceans. - 2169-9275. ; 126:12
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Tidskriftsartikel (refereegranskat)abstract
- Widespread ice shelf thinning has been recorded in the Amundsen Sea in recent decades, driven by basal melting and intrusions of relatively warm Circumpolar Deep Water (CDW) onto the continental shelf. The Dotson Ice Shelf (DIS) is located to the south of the Amundsen Sea polynya, and has a high basal melting rate because modified CDW (mCDW) fills the Dotson-Getz Trough (DGT) and reaches the base of the ice shelf. Here, hydrographic data in the DGT obtained during seven oceanographic surveys from 2007 to 2018 were used to study the interannual variation in mCDW volume and properties and their causes. Although mCDW volume showed relatively weak interannual variations at the continental shelf break, these variations intensified southward and reached a maximum in front of the DIS. There, the mCDW volume was ∼8,000km3 in 2007, rapidly decreased to 4,700km3 in 2014 before rebounding to 7,300km3 in 2018. We find that such interannual variability is coherent with local Ekman pumping integrated along the DGT modulated by the presence of sea ice, and complementing earlier theories involving shelf break winds only. The interannual variability in strength of the dominant south-southeast coastal wind modulates the amplitude of Ekman upwelling along the eastern boundary of the Amundsen Sea polynya during the austral summers of the surveyed years, apparently leading to change in the volume of mCDW along the DGT. We note a strong correlation between the wind variability and the longitudinal location of the Amundsen Sea Low. © 2021. The Authors.
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| 8. |
- Korlén, S., et al.
(författare)
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Exploring staff experience of economic efficiency requirements in health care : A mixed method study
- 2019
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Ingår i: International Journal of Health Planning and Management. - : Wiley. - 0749-6753 .- 1099-1751. ; 34:4, s. 1439-1455
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Tidskriftsartikel (refereegranskat)abstract
- Background: Economic resources are limited in health care, and governance strategies are used to push provider organizations to use resources efficiently. Although studies show that hybrid managers are successful in reconciling economic efficiency requirements with professional values to meet patient needs, surprisingly few studies focus on staff. The aim of this study is to explore staff members' experience of economic efficiency requirements. Methods: A mixed method design was applied, targeting multi-professional staff in the Department of Rehabilitation Medicine in a Swedish university hospital. Survey data was collected (n = 93), followed by focus-group interviews to support the understanding of the quantitative findings. Findings: The findings show that health care staff is knowledgeable and intrinsically motivated to consider efficiency requirements, albeit it should not dominate clinical decisions. However, staff experiences little influence over resource allocation and identifies limitations in the system's abilities to meet patient needs. Staff experience incorporates a local unit and a system perspective. Conclusion: Staff members are aware of economic efficiency requirements and will behave accordingly if patients are not at risk. However, their engagement seems to rely on how economic efficiency requirements are handled at multiple system levels and their trust in the system to fairly support patient needs.
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| 9. |
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| 10. |
- Korlén, S., et al.
(författare)
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Leaders as intermediates between economic incentive models and professional motivation
- 2018
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Ingår i: Läkartidningen. - : Swedish Medical Association. - 0023-7205 .- 1652-7518. ; 115:22-23
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Tidskriftsartikel (refereegranskat)abstract
- The application of economic incentives to providers in health care governance is debated. Advocates argue that it drives efficiency and improvement, opponents claim that it leads to unintended consequences for patients and professionals. Research shows that incentives can increase well-defined activities and targets, but there is a lack of substantial evidence that applications in health care lead to desired outcomes. The motivational literature acknowledges internal sources of motivation as important determinants of behavior, and the literature about professions suggests that professional values of serving patient needs is a key motivator. The management literature identifies the important role of leaders in aligning external demands and rewards to staff preferences, using their own management and leadership skills. Findings in health services research confirm the vital role of leaders for successful implementation and improvement work. In sum, internal motivators and the role of leaders are important to acknowledge also when understanding how economic governance models are put into practice. Our recently published qualitative case study provides empirical examples of how clinical leaders function as intermediaries between a local care choice model, including financial incentives, and the motivation of staff. The strategies deployed by the leaders aimed to align the economic logics of the model to the professional focus on increasing patient value. The main conclusion from these empirical examples, as well as previous research, is that health care managers play a key role in aligning economic incentive models with professional values and in translating such models in to feasible tasks related to the provision of high quality care.
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