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Surface mass balance and climate of the Last Glacial Maximum Northern Hemisphere ice sheets: simulations with CESM2.1
Get PDFThe Last Glacial Maximum (LGM, from ∼26 to 20 ka BP) was the most recent period with large ice sheets in Eurasia and North America. At that time, global temperatures were 5–7 ∘C lower than today, and sea level ∼125 m lower. LGM simulations are useful to understand earth system dynamics, including climate–ice sheet interactions, and to evaluate and improve the models representing those dynamics. Here, we present two simulations of the Northern Hemisphere ice sheet climate and surface mass balance (SMB) with the Community Earth System Model v2.1 (CESM2.1) using the Community Atmosphere Model v5 (CAM5) with prescribed ice sheets for two time periods that bracket the LGM period: 26 and 21 ka BP. CESM2.1 includes an explicit simulation of snow/firn compaction, albedo, refreezing, and direct coupling of the ice sheet surface energy fluxes with the atmosphere. The simulated mean snow accumulation is lowest for the Greenland and Barents–Kara Sea ice sheets (GrIS, BKIS) and highest for British and Irish (BIIS) and Icelandic (IcIS) ice sheets. Melt rates are negligible for the dry BKIS and GrIS, and relatively large for the BIIS, North American ice sheet complex (NAISC; i.e. Laurentide, Cordilleran, and Innuitian), Scandinavian ice sheet (SIS), and IcIS, and are reduced by almost a third in the colder (lower temperature) 26 ka BP climate compared with 21 ka BP. The SMB is positive for the GrIS, BKIS, SIS, and IcIS during the LGM (26 and 21 ka BP) and negative for the NAISC and BIIS. Relatively wide ablation areas are simulated along the southern (terrestrial), Pacific and Atlantic margins of the NAISC, across the majority of the BIIS, and along the terrestrial southern margin of the SIS. The integrated SMB substantially increases for the NAISC and BIIS in the 26 ka BP climate, but it does not reverse the negative sign. Summer incoming surface solar radiation is largest over the high interior of the NAISC and GrIS, and minimum over the BIIS and southern margin of NAISC. Summer net radiation is maximum over the ablation areas and minimum where the albedo is highest, namely in the interior of the GrIS, northern NAISC, and all of the BKIS. Summer sensible and latent heat fluxes are highest over the ablation areas, positively contributing to melt energy. Refreezing is largest along the equilibrium line altitude for all ice sheets and prevents 40 %–50 % of meltwater entering the ocean. The large simulated melt for the NAISC suggests potential biases in the climate simulation, ice sheet reconstruction, and/or highly non-equilibrated climate and ice sheet at the LGM time.publishedVersio
Investigating pelagic biodiversity and gelatinous zooplankton communities in the rapidly changing European Arctic: An eDNA metabarcoding survey
Get PDFFram Strait, the gateway between the Arctic and Atlantic Oceans, is undergoing major climate change-induced physical and biological transformations. In particular, rapid warming and ongoing “Atlantification” are driving species range shifts and altering food web structures in the Arctic. Understanding and predicting the consequences of these processes on future ecosystems requires detailed assessments of local and pelagic biodiversity. Gelatinous zooplankton (GZP) is an important component of pelagic communities, and recent evidence indicates that such communities are undergoing major changes in the Fram Strait. However, as sampling GZP is challenging, they are regularly underestimated in biodiversity, distribution, and abundance. To overcome this and address existing ecological knowledge gaps, we investigated patterns of pelagic metazoan diversity in Fram Strait using environmental DNA (eDNA) metabarcoding of the cytochrome c oxidase I (COI) gene. We successfully detected a broad range of taxa from the marine metazoan and GZP communities across sampling locations and ocean depth zones. We demonstrate the vertical structuring of diversity and elucidate relationships between taxa and water mass indicators, such as salinity and temperature. Furthermore, when comparing eDNA data with net and video transect data for GZP at the same period and location, we found that eDNA uncovered a higher number of taxa, including several that were not detected by the other methods. This study is a contribution to the formation of baseline Arctic GZP biodiversity datasets, as well as future research on changing marine metazoan biodiversity and community composition.publishedVersio
Autonomous UAV Exploration and Mapping in Uncharted Terrain Through Boundary-Driven Strategy
Get PDFUnmanned Aerial Vehicles (UAVs) play a crucial role in exploring unpredictable terrains, such as accident sites and search zones. These robots require autonomous navigation and precise path planning to operate safely and efficiently in dynamic environments. UAVs must balance navigation accuracy and energy efficiency constraints during autonomous operations. This paper introduces an innovative boundary-driven mapping strategy for UAV exploration in unknown environments. The study proposes a novel approach for boundary extraction using deep learning and presents a decision-making methodology to enable the UAV to select the most optimal frontier for exploration based on deep learning-derived information. The primary objective is to efficiently expand the unknown map. The research demonstrates a significant reduction in exploration time within a simulated environment, achieving better performance compared to other methodologies documented in the literature. The results highlight the effectiveness and efficiency of the proposed strategy in terms of mapping exploration.publishedVersio
ForCenS-LGM: a dataset of planktonic foraminifera species assemblage composition for the Last Glacial Maximum
Get PDFSpecies assemblage composition of marine microfossils offers the possibility to investigate ecological and climatological change on time scales inaccessible using conventional observations. Planktonic foraminifera - calcareous zooplankton - have an excellent fossil record and are used extensively in palaeoecology and palaeoceanography. During the Last Glacial Maximum (LGM; 19,000 – 23,000 years ago), the climate was in a radically different state. This period is therefore a key target to investigate climate and biodiversity under different conditions than today. Studying LGM climate and ecosystems indeed has a long history, yet the most recent global synthesis of planktonic foraminifera assemblage composition is now nearly two decades old. Here we present the ForCenS-LGM dataset with 2,365 species assemblage samples collected using standardised methods and with harmonised taxonomy. The data originate from marine sediments from 664 sites and present a more than 50% increase in coverage compared to previous work. The taxonomy is compatible with the most recent global core top dataset, enabling direct investigation of temporal changes in foraminifera biogeography and facilitating seawater temperature reconstructions.publishedVersio
Evaluation of safe operating envelope for CO2 injection under uncertain rock mechanical parameters and earth stresses
Get PDFCarbon Capture and Storage (CCS) is a pre-requisite to decarbonize CO2 emissions from industrial sectors and as an industry capable of compensating for hard-to-abate emissions in a net zero scenario. A method was developed to evaluate the geomechanical constraints and safe operating envelope as function of pore pressure and temperature. The probability of failure was estimated from uncertain input stiffness and strength data, and as cooling and re-pressurization shifts the in-situ effective stresses, the safe operating envelope was determined, here given by pressure and temperature. Onshore storages nearby industrial clusters enable energy and cost-effective handling of CO2. In the South-Eastern European region, onshore depleted oil and gas fields located nearby high-emitting industries may developed into CO2 storages. This paper describes a method for determining maximum fluid pressure as function of temperature from geomechanical restrictions. The method was employed on a practical example used to evaluate the safe operation envelope for a pilot CO2 injection site into a depleted onshore naturally fractured carbonate oil and gas field. The tool uses Monte Carlo simulations to perform geomechanical stability analyses by sampling from the inherent uncertainty of the input parameters to probability of failure as function of pressure and temperature. The risk of re-opening natural fractures, induced fracturing and fault reactivation are evaluated so the safe operating envelope can be obtained. The uncertainty of the input parameters is thus directly reflected in the safe operating envelope – thus providing an effective communication of value information to external stake holders when maturing a CO2 storage pilot.publishedVersio
The effect of physical activity on anxiety symptoms among children and adolescents with mental health disorders: a research brief
Get PDFackground: Anxiety is prevalent among children and adolescents (termed youths), and leads to reduced quality of life, disability, loss of education and reduced life-span. Physical activity has shown promising effects on symptoms of anxiety in adult populations, and an increasing amount of research has also demonstrated some effect in youth. However, physical activity is not widely used in youth mental health care, and research is very limited. Methods/design: This single arm, pre-post study explores the effect of a manualized physical activity-based 14-session intervention termed Confident, Active and Happy Youth. Participants are youth attending specialized mental health care (N=51, M age = 13.4, SD = 2.2). Changes in anxiety symptoms are examined using mixed models with residual maximum likelihood (REML). The potential effect of anxiety subtype differences, participant age, comorbidity, and time spent in out-patient care are explored. Results: Youths did not report any effect on anxiety symptoms after participation in CAHY, however, their parents report a significant reduction in youth’s anxiety symptoms in general (b = -0.11, 95%, CI: -0.21 to -0.01) and specifically for social phobia (b = -0.19, 95% CI: -0.35 to -0.03). Age and comorbidity showed no significant effect on anxiety symptoms post treatment. Prior treatment time in youth mental health care demonstrated inconclusive results. Conclusion: The study finds initial evidence of symptomatic change in a clinical population of youth’s receiving a physical activity-based intervention. Our research provides preliminary support for physical activity as a supplementary treatment method for mental health disorders among youths.publishedVersio
Fjernarbeid som arbeidsform og nytt politikkområde: kunnskap og aktuelle tiltak for norske distriktskommuner
Get PDFFormålet med denne rapporten er å presentere kunnskap om fordeler og ulemper ved fjernarbeid, samt forhold som er viktig å vektlegge for virksomheter for å tilrettelegge for denne arbeidsformen. Rapporten tar utgangspunkt i at digitalisering og nye organisasjons- og ledelsesformer de siste par tiårene har skapt betydelige endringer i måten vi jobber og samhandler i arbeidslivet. En konsekvens er at arbeid i stadig større grad kan utføres hvor som helst ved bruk av informasjons- og kommunikasjonsteknologi (IKT) for samhandling og arbeidsutførelse. Kunnskapsgrunnlaget er basert på en gjennomgang av sentrale forskningsbidrag og intervjuer med både arbeidstakere og arbeidsgivere med fjernarbeidserfaring, samt virksomheter som kan ha en rolle i tilrettelegging for fjernarbeid. I tillegg presenteres også resultater fra en arbeidssamling med fire kommuner i Hardangerregionen, hvor formålet var å bruke kunnskapsgrunnlaget for å starte diskusjoner om muligheter for tilrettelegging for fjernarbeid og utarbeidelse av en fjernarbeidspolitikk for disse kommunene. Avslutningsvis gis en kort oppsummering og noen forskningsbaserte anbefalingerFjernarbeid som arbeidsform og nytt politikkområde: kunnskap og aktuelle tiltak for norske distriktskommunerpublishedVersio
Calibration of Thixotropic and Viscoelastic Shear-Thinning Fluids Using Pipe Rheometer Measurements
Get PDFSome non-Newtonian fluids have time-dependent rheological properties like a shear stress that depends on the shear history or a stress overshoot that is a function of the resting time, when fluid movement is started. The rheological properties of such complex fluids may not stay constant while they are used in an industrial process, and it is therefore desirable to measure these properties frequently and with a simple and robust device like a pipe rheometer. This paper investigated how the time-dependent rheological properties of a thixotropic and viscoelastic shear-thinning fluid can be extracted from differential pressure measurements obtained at different flowrates along a circular pipe section. The method consists in modeling the flow of a thixotropic version of a Quemada fluid and solving the inverse problem in order to find the model parameters using the measurements made in steady-state conditions. Also, a Maxwell linear viscoelastic model was used to reproduce the stress overshoot observed when starting circulation after a resting period. The pipe rheometer was designed to have the proper features necessary to exhibit the thixotropic and viscoelastic effects that were needed to calibrate the rheological model parameters. The accuracy of rheological meas-urements depends on understanding the effects that can influence the observations and on a proper design that takes advantage of these side effects instead of attempting to eliminate them.Calibration of Thixotropic and Viscoelastic Shear-Thinning Fluids Using Pipe Rheometer MeasurementspublishedVersio
Utfisking av rømt oppdrettsfisk på oppdrag for OURO i utvalgte vassdrag i Sør-Norge høsten 2023
Get PDFHøsten 2023 utførte LFI NORCE, i samarbeid med Rådgivende Biologer AS, utfisking av rømt oppdrettslaks i 14 vassdrag i Vestland og Rogaland etter avtale med oppdrettsnæringens sammenslutning for utfisking av rømt oppdrettsfisk (OURO). Hensikten var å redusere risiko for genetisk påvirkning på ville laksebestander ved å fjerne rømt oppdrettsfisk fra vassdragene. Forekomst av oppdrettsfisk ble kartlagt ved snorkling/drivtelling. Utfisking ble utført harpun, not, samt lokal utfisking ved stangfiske av lokale grunneierlag/fiskerlag etter ordinær fiskesesong. Totalt ble det høsten 2023 fisket ut 102 oppdrettsfisk fra de aktuelle vassdragene, fordelt på 82 oppdrettslaks og 20 regnbueaure.publishedVersio
“User participation? Isn’t that what i do all day?” Implementing user participation in Norwegian mental health outpatient clinics: a street-level bureaucrat perspective
Get PDFIn 2019, care pathways for specialist mental health services were officially launched in Norway. These pathways were designed according to several goals to improve services. One of the overall goals was to increase user participation. The purpose of this study was to examine how professionals, in their role as street-level bureaucrats, interpreted the overall goal of increased user participation and how this interpretation influenced the involvement of patients in treatment facilitation. A case study was conducted at one outpatient clinic for adults in western Norway using 10 qualitative, in-depth interviews with treatment personnel. Additionally, user participation in the care pathway was evaluated. The results indicated that mental health professionals interpreted the overall goal as indicating that user participation are integrated into professional practice, not something that could be isolated alone. Furthermore, the idea of involving patients in treatment decisions was rejected by utilizing two coping strategies: one strategy was understood as a mechanism of ‘routinizing’, whereby providers promoted the method they practice, and the other strategy was a mechanism of ‘rationing’, whereby providers became gatekeepers of access to certain services. By investigating street-level bureaucracy theory and related coping mechanisms, this study shows how these two mechanisms may move the provision of care away from patients to benefit themselves in a public service gap where there are never enough resources.publishedVersio