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Carbon cycle feedbacks in an idealized simulation and a scenario simulation of negative emissions in CMIP6 Earth system models
Full text linkLimiting global warming to well below 2 ∘C by the end of the century is an ambitious target that requires immediate and unprecedented emission reductions. In the absence of sufficient near-term mitigation, this target will only be achieved by carbon dioxide removal (CDR) from the atmosphere later during this century, which would entail a period of temperature overshoot. Aside from the socio-economic feasibility of large-scale CDR, which remains unclear, the effects on biogeochemical cycles and climate are key to assessing CDR as a mitigation option. Changes in atmospheric CO2 concentration and climate alter the CO2 exchange between the atmosphere and the underlying carbon reservoirs of the land and the ocean. Here, we investigate carbon cycle feedbacks under idealized and more realistic overshoot scenarios in an ensemble of Earth system models. The responses of oceanic and terrestrial carbon stocks to changes in atmospheric CO2 concentration and changes in surface climate (the carbon–concentration feedback and the carbon–climate feedback, quantified by the feedback metrics β and γ, respectively) show a large hysteresis. This hysteresis leads to growing absolute values of β and γ during phases of negative emissions. We find that this growth over time occurs such that the spatial patterns of feedbacks do not change significantly for individual models. We confirm that the β and γ feedback metrics are a relatively robust tool to characterize inter-model differences in feedback strength since the relative feedback strength remains largely stable between phases of positive and negative emissions and between different simulations, although exceptions exist. When the emissions become negative, we find that the model uncertainty (model disagreement) in β and γ increases more strongly than expected from the assumption that the uncertainties would accumulate linearly with time. This indicates that the model response to a change from increasing to decreasing forcing introduces an additional layer of uncertainty, at least in idealized simulations with a strong signal. We also briefly discuss the existing alternative definition of feedback metrics based on instantaneous carbon fluxes instead of carbon stocks and provide recommendations for the way forward and future model intercomparison projects.publishedVersio
Overgrepsmottak 2023 - Status etter innføring av Nasjonal faglig retningslinje for kvalitet og kompetanse i overgrepsmottak
Full text linkForordI juli 2021 publiserte Helsedirektoratet Nasjonal faglig retningslinje for kvalitet og kompetanse i overgrepsmottak. Denne retningslinjen kom bl.a. som en følge av at både Nasjonalt kompetansesenter for legevaktmedisin (NKLM) og Nordlandsforskning hadde dokumentert utfordringer ved overgrepsmottakene relatert til bl.a. manglende juridisk forankring, ulik og usikker finansiering, lite tilfredsstillende vaktordninger og beredskap, og ulik kompetanse og oppfølging av pasientene. Nasjonal faglig retningslinje for kvalitet og kompetanse i overgrepsmottak har en rekke faglige anbefalinger for å sikre god kvalitet og hindre uønsket variasjon i tjenesten. NKLM har undersøkt forholdene ved alle landets 23 overgrepsmottak for å kartlegge hvordan status er ved overgrepsmottakene etter at helseforetakene har fått klare retningslinjer for tjenesten.publishedVersio
IORSim: A Mathematical Workflow for Field‑Scale Geochemistry Simulations in Porous Media
Full text linkReservoir modeling consists of two key components: the reproduction of the historical performance and the prediction of the future reservoir performance. Industry-standard reservoir simulators must run fast on enormous and possibly unstructured grids while yet guaranteeing a reasonable representation of physical and chemical processes. However, computational demands limit simulators in capturing involved physical and geochemical mechanisms, especially when chemical reactions interfere with reservoir flow. This paper presents a mathematical workflow, implemented in IORSim, that makes it possible to add geochemical calculations to porous media flow simulators without access to the source code of the original host simulator. An industry-standard reservoir simulator calculates velocity fields of the fluid phases (e.g., water, oil, and gas), while IORSim calculates the transport and reaction of geochemical components. Depending on the simulation mode, the geochemical solver estimates updated relative and/or capillary pressure curves to modify the global fluid flow. As one of the key innovations of the coupling mechanism, IORSim uses a sorting algorithm to permute the grid cells along flow directions. Instead of solving an over-dimensionalized global matrix calling a Newton–Raphson solver, the geochemical software tool treats the species balance as a set of local nonlinear problems. Moreover, IORSim applies basis swapping and splay tree techniques to accelerate geochemical computations in complex full-field reservoir models. The presented work introduces the mathematical IORSim concept, verifies the chemical species advection, and demonstrates the IORSim computation efficiency. After validating the geochemical solver against reference software, IORSim is used to investigate the impact of seawater injection on the NCS Ekofisk reservoir chemistry.publishedVersio
Wind Shear Effects in Convection–Permitting Models Influence MCS Rainfall and Forcing of Tropical Circulation
Full text linkMesoscale Convective Systems (MCSs) play a critical role in tropical rainfall patterns and circulations. To reduce persistent biases and improve understanding of the climate system, international groups have called for unprecedented investment in global convection–permitting (CP) climate models. It is essential such models accurately represent MCSs, and in particular environmental interactions such as dynamical control by wind shear. We show that in representative current generation CP simulations, MCS updraft entrainment decreases with shear, leading to a realistic increase of extreme rainfall. We find the control of environmental shear extends to mean storm rainfall and anvil heights. The simulation of these effects depends strongly on model physics in both CP and parameterized models. We show that in West Africa, MCS shear response influences the zonal distribution of storm diabatic heating, modifying upscale impacts of convection. Our results demonstrate key tests for focused process–based assessment of CP model fidelity.publishedVersio
Advances in InSAR Analysis of Permafrost Terrain
Full text linkDifferential interferometric synthetic aperture radar (InSAR) is a remote sensing technique for measuring surface displacements with precision down to millimeters, most commonly from satellites. In permafrost landscapes, InSAR measurements can provide valuable information on geomorphic processes and hazards, including thaw subsidence and frost heave, thermokarst, and permafrost creep. We first review recent progress in InSAR data availability, InSAR processing and uncertainty analysis methods relevant to permafrost studies. These technical advances have contributed to our understanding of surface deformation in flat and sloping terrain in polar and mountainous regions. We emphasize two emerging trends. First, InSAR increasingly enables insight into the mechanisms, controls, and drivers of permafrost landscape dynamics on subseasonal to decadal time scales. Second, InSAR observations in conjunction with models enable novel ways to infer subsurface parameters, such as near-surface ground ice content and active layer thickness. We anticipate that in the coming decade, InSAR will mature into a widely used operational tool for monitoring, modeling, and planning across rapidly changing permafrost landscapes.publishedVersio
Glacial-interglacial Circumpolar Deep Water temperatures during the last 800 000 years: estimates from a synthesis of bottom water temperature reconstructions
Full text linkFuture climate and sea level projections depend sensitively on the response of the Antarctic Ice Sheet to ocean-driven melting and the resulting freshwater fluxes into the Southern Ocean. Circumpolar Deep Water (CDW) transport across the Antarctic continental shelf and into cavities beneath ice shelves is increasingly recognised as a crucial heat source for ice shelf melt. Quantifying past changes in the temperature of CDW is therefore of great benefit for modelling ice sheet response to past warm climates, for validating paleoclimate models, and for putting recent and projected changes in CDW temperature into context. Here we compile the available bottom water temperature reconstructions representative of CDW over the past 800 kyr. Estimated interglacial warming reached anomalies of +0.6 ± 0.4 °C (MIS 11) and +0.5 ± 0.5 °C (MIS 5) relative to present. Glacial cooling typically reached anomalies of ca. −1.5 to −2 °C, therefore maintaining positive thermal forcing for ice shelf melt even during glacials in the Amundsen Sea region of West Antarctica. Despite high variance amongst a small number of records and poor (4 kyr) temporal resolution, we find persistent and close relationships between our estimated CDW temperature and Southern Ocean sea surface temperature, Antarctic surface air temperature, and global deep-water temperature reconstructions at glacial-cycle timescales. Given the important role that CDW plays in connecting the world's three main ocean basins and in driving Antarctic Ice Sheet mass loss, additional temperature reconstructions targeting CDW are urgently needed to increase temporal and spatial resolution and to decrease uncertainty in past CDW temperatures – whether for use as a boundary condition, for model validation, or for understanding past oceanographic changes.publishedVersio
Intervening by staying professional: How Nordic environmental journalists make sense of their roles
Full text linkThe notion of intervention is gaining traction among Western environmental journalists. While existing research has predominantly focused on countries outside the Nordic region, in our study we investigate the self-perceptions of professional journalists in the Nordic countries of Finland, Iceland, Norway, and Sweden. Through semi-structured interviews, we examine the roles that Nordic journalists construct when reflecting on covering the environmental beat, paying particular attention to how they make sense of the idea of intervening – that is, their involvement in interpreting, making sense of, and engaging the public in environmental issues. Using thematic qualitative analysis to analyse the interviews, we have identified four journalistic roles: 1) objective news provider, 2) critical watchdog, 3) sense-maker and educator, and 4) environmental advocate. Our findings suggest that Nordic journalists intervene byadhering to professional norms and practices and renegotiating them. While the role of objective news provider remains prominent among Nordic journalists, it is intertwined with various forms of intervention across all identified roles.publishedVersio
Legevaktkonsultasjoner for hodeskader blant eldre
Full text linkHodeskader er en hyppig årsak til innleggelse i sykehus, og pasientene kommer ofte via legevakt. Denne studien ble gjennomført for å undersøke endringer i legevaktkonsultasjoner på grunn av hodeskader for pasienter ≥ 50 år.publishedVersio
Late Miocene onset of the modern Antarctic Circumpolar Current
Full text linkThe Antarctic Circumpolar Current plays a pivotal role in global climate through its strong influence on the global overturning circulation, ocean heat and CO2 uptake. However, when and how the Antarctic Circumpolar Current reached its modern-like characteristics remains disputed. Here we present neodymium isotope and sortable silt records from sediment cores in the Southwest Pacific and South Indian oceans spanning the past 31 million years. Our data indicate that a circumpolar current like that of today did not exist before the late Miocene cooling. These findings suggest that the emergence of a homogeneous and deep-reaching strong Antarctic Circumpolar Current was not linked solely to the opening and deepening of Southern Ocean Gateways triggering continental-scale Antarctic Ice Sheet expansion during the Eocene–Oligocene Transition (∼34 Ma). Instead, we find that besides tectonic pre-conditioning, the expansion of the Antarctic Ice Sheet and sea ice since the middle Miocene Climate Transition (∼14 Ma) played a crucial role. This led to stronger density contrast and intensified Southern Westerly Winds across the Southern Ocean, establishing a vigorous deep-reaching circumpolar flow and an enhanced global overturning circulation, which amplified the late Cenozoic global cooling.publishedVersio
Self-injurious thoughts and behaviours as the reason for contact to Norwegian emergency primary care centres: an observational study
Full text linkObjective To describe and compare contacts regarding self-injurious thoughts and behaviours to other contacts to emergency primary care. Design Observational study. Setting A sentinel network of seven emergency primary care centres throughout Norway. Subjects Initial contacts regarding patients 10 years and older during 12 consecutive months (11/2021–10/2022). Main outcome measures Contacts due to self-injurious thoughts and behaviours.publishedVersio