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An analysis of winter rain-on-snow climatology in Svalbard
No full textRain-on-snow (ROS) events are becoming an increasingly common feature of the wintertime climate Svalbard in the High Arctic due to a warming climate. Changes in the frequency, intensity, and spatial distribution of wintertime ROS events in Svalbard are important to understand and quantify due their wide-ranging impacts on the physical environment as well as on human activity. Due to the sparse nature of ground observations across Svalbard, tools for mapping and long-term monitoring of ROS events over large spatial areas are reliant on remote sensing, snow models and atmospheric reanalyses. However, different methods of identifying and measuring ROS events can often present different interpretations of ROS climatology. This study compares a recently published Synthetic Aperture Radar (SAR) based ROS dataset for Svalbard to ROS derived from two snow models and a reanalysis dataset for 2004–2020. Although the number of ROS events differs across the datasets, all datasets exhibit both similarities and differences in the geographical distribution of ROS across the largest island, Spitsbergen. Southern and western coastal areas experience ROS most frequently during the wintertime, with the early winter (November–December) experiencing overall most events compared to the spring (March–April). Moreover, we find that different temperature thresholds are required to obtain the best spatial agreement of ROS events in the model and reanalysis datasets with ground observations. The reanalysis dataset evaluated against ground observations was superior to the other datasets in terms of accuracy due to the assimilation of ground observations into the dataset. The SAR dataset consistently scored lowest in terms of its overall accuracy due to many more false detections, an issue which is most likely explained by the persistence of moisture in the snowpack following the end of a ROS event. Our study not only highlights some spatial differences in ROS frequency and trends but also how comparisons between different datasets can confirm knowledge about the climatic variations across Svalbard where in-situ observations are sparse.publishedVersio
Predicted multispecies unintended effects from outdoor genome editing
Get PDFCRISPR/Cas9, a potent genetic engineering tool widely adopted in agriculture, is capable of introducing new characteristics into plants on a large scale and without conventional breeding methods. Despite its remarkable efficiency, concerns have arisen regarding unintended consequences in uncontrolled environments. Our aim was to assess potential activity in organisms that could be exposed to genome editing in uncontrolled environments. We developed three scenarios, using irrigation, fumigation and fertilization as delivery methods, based on outdoor uses in agriculture, namely pest and disease control. Using publicly available software (Cas-OFFinder, NCBI Genome Data Viewer and STRING), off-target effects were predicted in multiple species commonly found in the agroecosystem, including humans (16 of 38 (42 %) sampled). Metabolic enrichment analysis (gene IDs), by connecting off-target genes into a physiological network, predicted effects on the development of nervous and respiratory systems. Our findings emphasize the importance of exercising caution when considering the use of this genome editing in uncontrolled environments. Unintended genomic alterations may occur in unintended organisms, underscoring the significance of understanding potential hazards and implementing safety measures to protect human health and the environment.publishedVersio
The chronically ill in the labour market – are they hierarchically sorted by education?
Get PDFBackground The chronically ill as a group has on average lower probability of employment compared to the general population, a situation that has persisted over time in many countries. Previous studies have shown that the prevalence of chronic diseases is higher among those with lower levels of education. We aim to quantify the double burden of low education and chronic illness comparing the differential probabilities of employment between the chronically ill with lower, medium, and high levels of education and how their employment rates develop over time. Methods Using merged Norwegian administrative data over a 11-year period (2008–2018), our estimations are based on multivariable regression with labour market and time fixed effects. To reduce bias due to patients’ heterogeneity, we included a series of covariates that may influence the association between labour market participation and level of education. To explicitly explore the ‘shielding effect’ of education over time, the models include the interaction effects between chronic illness and level of education and year. Results The employment probabilities are highest for the high educated and lowest for chronically ill individuals with lower education, as expected. The differences between educational groups are changing over time, though, driven by a revealing development among the lower-educated chronically ill. That group has a significant reduction in employment probabilities both in absolute terms and relative to the other groups. The mean predicted employment probabilities for the high educated chronic patient is not changing over time indicating that the high educated as a group is able to maintain labour market participation over time. Additionally, we find remarkable differences in employment probabilities depending on diagnoses. Conclusion For the chronically ill as a group, a high level of education seems to “shield” against labour market consequences. The magnitude of the shielding effect is increasing over time leaving chronically ill individuals with lower education behind. However, the shielding effect varies in size between types of chronic diseases. While musculoskeletal, cardiovascular and partly cancer patients are “sorted” hierarchically according to level of education, diabetes, respiratory and mental patients are not.publishedVersio
Is it enough to enable freight? Modes of governance for urban logistics in Norway
Get PDFUrban freight transport is central to urban societies, and yet urban authorities have traditionally left it to private actors to resolve freight challenges. Urban authorities rely on different governance strategies to address freight that result in fragmented freight governance, as many solutions are fixed in time, sector, or place. Drawing on Bulkeley and Kern’s typology of four modes of governance – self-governing, governing through enabling, governing by provision, and governing by authority – this paper asks: in what ways do urban authorities use different modes of governance in the case of urban logistics? Empirically, the paper looks at the modes of freight governance through an explorative workshop, document analysis, and interviews from Norway’s four largest cities – Bergen, Stavanger, Oslo and Trondheim. It finds that these cities are limiting themselves to ‘less confrontational’ modes based on accommodating freight activities, which hinders institutionalisation of knowledge and prevents public governance from serving as a coordinating factor for urban logistics.Is it enough to enable freight? Modes of governance for urban logistics in NorwaypublishedVersio
What goes in must come out: the oceanic outgassing of anthropogenic carbon
Get PDFAbout 25% of the emitted anthropogenic CO2 is absorbed by the ocean and transported to the interior through key gateways, such as the Southern Ocean or the North Atlantic. Over the next few centuries, anthropogenic CO2 is then redistributed by ocean circulation and stored mostly in the upper layers of the subtropical gyres. Because of the combined effects of (i) weakening buffering capacity, (ii) warming-induced lower solubility, (iii) changes in wind stress and (iv) changes in ocean circulation, there is a high confidence that the ocean sink will weaken in the future. Here, we use IPCC-class Earth System Model (ESM) simulations following the SSP1-2.6 and SSP5-8.5 climate change scenarios extended to the year 2300 to reveal that anthropogenic CO2 begins to outgas in the subtropical gyres of both hemispheres during the summer months of the 21st century. In 2100, about 53% of the surface ocean experience outgassing at least one month in a year in SSP1-2.6, against 37% in SSP5-8.5. After 2100, this fraction keeps increasing, reaching 63% by 2300 in SSP5-8.5 while stabilizing at 55% in SSP1-2.6. This outgassing pattern is driven by the rapid increase in oceanic pCO2, faster than the atmospheric pCO2, due to the combined effect of both rapid warming and long-term accumulation of anthropogenic carbon in these regions. These findings call for increased observation efforts in these areas, particularly in the subtropical gyres of the Southern Hemisphere, in order to detect future release of anthropogenic carbon and accurately constrain the future carbon budget.publishedVersio
Using Shelf-Edge Transport Composition and Sensitivity Experiments to Understand Processes Driving Sea Level on the Northwest European Shelf
Get PDFVariability in ocean currents, temperature and salinity drive dynamic sea level (DSL) variability on the Northwest European Shelf (NWES). It is dominated by mass variations, with steric signals relatively small. A mechanistic explanation of how ocean dynamics relates to the mass component of NWES sea level variability is required. We use regional ocean model experiments to isolate sources of variability and then investigate the effect on monthly to-interannual DSL variability together with the simulated momentum budgets along the shelfbreak. Regional (local) wind and non-regional (remote) forcing are important on the NWES. For the local wind forcing, the net mass flux onto the shelf, which drives a shelf-mean mode of DSL variability, results from a combination of surface Ekman, bottom Ekman and geostrophic flows and explains 73% of the variance in transport across the shelf-edge. The geostrophic flow is closely related to wind stress with a flow about half that of surface Ekman transport but in the opposite direction. For the remotely forced mass-flux across the shelf-edge, the geostrophic component explains 62% of the variance and bottom friction plays an important indirect role. The remotely forced variability, while relatively spatially uniform, is more important for explaining DSL variance over the western NWES. This mode of variability is sensitive to signals propagating northward via a thin strip of the southern boundary near the Portuguese coast, consistent with coastal trapped wave signals. It also appears to drive steric height in the Bay of Biscay, which is related to DSL on the shelf.publishedVersio
Assessment of Global Ocean Biogeochemistry Models for Ocean Carbon Sink Estimates in RECCAP2 and Recommendations for Future Studies
Get PDFThe ocean is a major carbon sink and takes up 25%–30% of the anthropogenically emitted CO2. A state-of-the-art method to quantify this sink are global ocean biogeochemistry models (GOBMs), but their simulated CO2 uptake differs between models and is systematically lower than estimates based on statistical methods using surface ocean pCO2 and interior ocean measurements. Here, we provide an in-depth evaluation of ocean carbon sink estimates from 1980 to 2018 from a GOBM ensemble. As sources of inter-model differences and ensemble-mean biases our study identifies (a) the model setup, such as the length of the spin-up, the starting date of the simulation, and carbon fluxes from rivers and into sediments, (b) the simulated ocean circulation, such as Atlantic Meridional Overturning Circulation and Southern Ocean mode and intermediate water formation, and (c) the simulated oceanic buffer capacity. Our analysis suggests that a late starting date and biases in the ocean circulation cause a too low anthropogenic CO2 uptake across the GOBM ensemble. Surface ocean biogeochemistry biases might also cause simulated anthropogenic fluxes to be too low, but the current setup prevents a robust assessment. For simulations of the ocean carbon sink, we recommend in the short-term to (a) start simulations at a common date before the industrialization and the associated atmospheric CO2 increase, (b) conduct a sufficiently long spin-up such that the GOBMs reach steady-state, and (c) provide key metrics for circulation, biogeochemistry, and the land-ocean interface. In the long-term, we recommend improving the representation of these metrics in the GOBMs.publishedVersio
Projected poleward migration of the Southern Ocean CO2 sink region under high emissions
Get PDFThe Southern Ocean is a major region of ocean carbon uptake, but its future changes remain uncertain under climate change. Here we show the projected shift in the Southern Ocean CO2 sink using a suite of Earth System Models, revealing changes in the mechanism, position and seasonality of the carbon uptake. The region of dominant CO2 uptake shifts from the Subtropical to the Antarctic region under the high-emission scenario. The warming-driven sea-ice melt, increased ocean stratification, mixed layer shoaling, and a weaker vertical carbon gradient is projected to together reduce the winter de-gassing in the future, which will trigger the switch from mixing-driven outgassing to solubility-driven uptake in the Antarctic region during the winter season. The future Southern Ocean carbon sink will be poleward-shifted, operating in a hybrid mode between biologically-driven summertime and solubility-driven wintertime uptake with further amplification of biologically-driven uptake due to the increasing Revelle Factor.publishedVersio
Microbial life in salt caverns and their influence on H2 storage – Current knowledge and open questions
Get PDFHydrogen will be one of the key components for renewable energy storage in the future energy systems as it can be stored in significant volumes to overcome daily to seasonal energy fluctuations. Subsurface storage in salt caverns will be a first step. These caverns are created by solution mining in underground salt formations. Despite the high salinity in this environment, salt caverns harbor microbial life. These microorganisms can not only survive in these caverns by using unique adaptation mechanisms, but they actually cause several risks to hydrogen storage. Different metabolisms can use hydrogen as electron donor, leading to hydrogen loss and in the worst case also to H2S formation. The knowledge on salt cavern microbiology and subsequent possible effects of hydrogen is still in its infancy and only a limited number of salt caverns have been investigated so far. This review summarizes the current knowledge and key questions about halophilic (salt-loving) microbes, their adaptation strategies, their origin and potential consequences of their metabolisms. It also discusses the major factors influencing microbial activities and potential risks. This review emphasizes that more research and field trials with extensive microbial monitoring are needed before hydrogen storage in a biologically active system can be safely achieved at a global scale.publishedVersio
Vibration-Based SHM in the Synthetic Mooring Lines of the Semisubmersible OO-Star Wind Floater under Varying Environmental and Operational Conditions
Get PDFAs the industry transitions toward Floating Offshore Wind Turbines (FOWT) in greater depths, conventional chain mooring lines become impractical, prompting the adoption of synthetic fiber ropes. Despite their advantages, these mooring lines present challenges in inspection due to their exterior jacket, which prevents visual assessment. The current study focuses on vibration-based Structural Health Monitoring (SHM) in FOWT synthetic mooring lines under uncertainty arising from varying Environmental and Operational Conditions (EOCs). Six damage detection methods are assessed, utilizing either multiple models or a single functional model. The methods are based on Vector Autoregressive (VAR) or Transmittance Function Autoregressive with exogenous input (TF- ARX) models. All methods are evaluated through a Monte Carlo study involving 1100 simulations, utilizing acceleration signals generated from a finite element model of the OO-Star Wind Floater Semi 10 MW wind turbine. With signals from only two measuring positions, the methods demonstrate excellent results, detecting the stiffness reduction of a mooring line at levels 10% through 50%. The methods are also tested for healthy cases, with those utilizing TF-ARX models achieving zero false alarms, even for EOCs not encountered in the training data.Vibration-Based SHM in the Synthetic Mooring Lines of the Semisubmersible OO-Star Wind Floater under Varying Environmental and Operational ConditionspublishedVersio