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Habitatkartlegging i Månavassdraget i 2024
Full text linkDenne rapporten sammenstiller resultatene av habitatkartlegging utført av NORCE LFI i Månavassdraget våren 2024. Habitat for laks og sjøørret, og menneskelige inngrep, ble kartlagt for hele anadrom strekning inkludert sideelvene Vemora, Tørla, Venåsgrova, Tøftelva, Skarelva, Månvasselva, Øspevasselva og Stavvasselva. Måna er relativt stri, med grovt substrat, og bra med skjul for ungfisk. Lite gytehabitat er vurdert å være flaskehalsen for produksjon av laks og sjøørret. Mengden gyteområder er høyst sannsynlig redusert som følge av menneskelige inngrep, og da i hovedsak kanalisering og avstenging av sideløp. Dette gjelder spesielt nedre ca. 6,5 km av elven, der forbygninger fra ulike tidsperioder har innsnevret elvebredden og avstengt sideløp og flomsletter. Vi foreslår å gjenåpne en rekke sideløp langs Måna for å utvide elven og gjenskape gyteområder. Tiltakene varierer fra store prosjekter til relativt enkle justeringer. Elveeierlaget har tidligere gjenåpnet en del sideløp ved å slippe vann inn via rør fra hovedelven, og vi foreslår også å gjøre en del justeringer av disse sideløpene. I tillegg foreslår vi å reetablere kantvegetasjon der denne mangler. Også i flere av sideelvene er det gjort betydelige inngrep. De fleste sideelvene er imidlertid så bratte at det ikke vurderes som hensiktsmessig å gjøre store restaureringstiltak. Mangel på gyteområder er den naturlige habitatflaskehalsen for laks og sjøørret i de fleste sideelvene. Det foreslås å utbedre to kunstige vandringshindre i Tørla, å utvide elvebredden i Venåsgrova, samt en del mindre omfattende tiltak.Habitatkartlegging i Månavassdraget i 2024publishedVersio
Net primary production annual maxima in the North Atlantic projected to shift in the 21st century
Full text linkShifts in the day of peak net primary production (NPP) were detected in different biogeochemical provinces of the North Atlantic (25–65° N). Most provinces displayed a shift toward earlier peak NPP, with the largest change points in the 21st century and in the northern parts of the domain. Furthermore, the occurrences of the first day with a mixed-layer depth (MLD) shallower than 40 m and the day of peak NPP are positively correlated over most of the domain. As was the case for the day of peak NPP, the largest change points for the day of MLD shallower than 40 m occur around or after the year 2000. Daily output from two fully coupled CMIP6 Earth system models, EC-Earth3-CC and NorESM2-LM, for the period 1750–2100 and under the SSP5-8.5 scenario, were used for the analysis. The ESM NPP data were compared with estimates derived from Carbon, Absorption and Fluorescence Euphotic-resolving (CAFE) satellite-based data. The ESMs showed significant differences from the CAFE model, though the timing of peak NPP was well captured for most provinces. The largest change points in the day of peak NPP occur earlier in EC-Earth3-CC than in NorESM2-LM. Although SSP5-8.5 is a scenario with very high warming, EC-Earth3-CC generates change points for most provinces in the early part of the 21st century, before the warming has deviated far from lower-emissions scenarios. NorESM2-LM displays the largest change points centered around the mid 21st century, with two out of eight provinces displaying the largest change point before the year 2050. The early timing of the detected shifts in some provinces in both ESMs suggests that similar shifts could already have been initiated or could start in the near future. This highlights the need for long-term monitoring campaigns in the North Atlantic.publishedVersio
Robust Optimization Using the Mean Model with Bias Correction
Full text linkOptimization of the expected outcome for subsurface reservoir management when the properties of the subsurface model are uncertain can be costly, especially when the outcomes are predicted using a numerical reservoir flow simulator. The high cost is a consequence of the approximation of the expected outcome by the average of the outcomes from an ensemble of reservoir models, each of which may need to be numerically simulated. Instead of computing the sample average approximation of the objective function, some practitioners have computed the objective function evaluated on the “mean model,” that is, the model whose properties are the means of properties of an ensemble of model realizations. Straightforward use of the mean model without correction for bias is completely justified only when the objective function is a linear function of the uncertain properties. In this paper, we show that by choosing an appropriate transformation of the variables before computing the mean, the mean model can sometimes be used for optimization without bias correction. However, because choosing the appropriate transformation may be difficult, we develop a hierarchical bias correction method that is highly efficient for robust optimization. The bias correction method is coupled with an efficient derivative-free optimization algorithm to reduce the number of function evaluations required for optimization. The new approach is demonstrated on two numerical porous flow optimization problems. In the two-dimensional well location problem with 100 ensemble members, a good approximation of the optimal location is obtained in 10 function evaluations, and a slightly better (nearly optimal) solution using bias correction is obtained using 216 function evaluations.publishedVersio
Myndigheters policy om tining av permafrost og skred i Longyearbyen
Full text linkBåde nasjonale politiske myndigheter, nasjonale fagmyndigheter og lokale myndigheter i Longyearbyen har jobbet mye med skred og skredsikring, særlig etter de to alvorlige snøskredene. Det finnes en politikk om skred, egen stortingsmelding, NVE er nasjonal skredmyndighet, og ny politikk og organisering utvikles bla. for bedre samordning. Også lokalt i Longyearbyen er det fokus på skred, imidlertid er det mest oppmerksomhet rundt snøskred, og langt mindre om andre skredtyper. Tining av permafrost skader infrastruktur på Svalbard. Det har lite oppmerksomhet i nasjonale politiske dokument, men omtales av nasjonale faglige myndigheter, særlig Klimaservicesenteret. Lokale aktører på Svalbard (Sysselmester, Lokalstyret og boligeiere) har mer fokus på permafrost enn nasjonale politiske myndigheter som håndterer tining av permafrost mer som enkeltsaker. Det mangler både en helhetlig tilnærming og politikk om tining av permafrost og plassering av et overordnet ansvar for feltet.Myndigheters policy om tining av permafrost og skred i LongyearbyenpublishedVersio
Feasibility of a physical activity intervention for children and adolescents with anxiety and depression
Full text linkBackground: Physical activity is identified as a key modifiable factor towards good short- and long-term mental health and has shown positive effects on anxiety and depression in children and adolescents. However, physical activity-based interventions are not a part of standard mental health care and evidence on the effect of such interventions is still lacking. A transdiagnostic, physical activity-based intervention was developed as a supplement to routine clinical care for youth in specialized child and adolescent mental health services. Methods: /design. The feasibility of the physical activity intervention (Confident, Active, and Happy Youth) was evaluated in an open-label study by assessing the recruitment process, acceptability, intervention suitability, contentment, and preliminary intervention effects in the form of youth and parent-rated anxiety and depressive symptoms. Physical activity levels were objectively measured using Actigraph™ physical activity sensors, and progression to a definitive study was evaluated in accordance with a priori criteria. Results: In total 21 of 25 eligible youth consented to participate, two dropped out of the intervention and 19 completed (76% of eligible participants). The retention rate among consenting participants was 89% and mean attendance to sessions was 83%. The suitability of the intervention was rated as good by the youth and their parents, and intervention contentment was rated high. Changes in youth and parent-rated symptom measures following the intervention were negligible, except for parent-rated anxiety symptoms assessed at 10-month follow-up. Accelerometer data indicated lower levels of moderate to vigorous activity during sessions than intended. No adverse effects were noted. Conclusion: This feasibility study met the pre-determined progression criteria to a definitive study. Thus, a larger trial with longer follow-up should be conducted to explore the effect of the intervention.publishedVersio
Fiskebiologiske undersøkelser i seks regulerte vassdrag i Hardanger i 2023
Full text linkSiden 2007 har det vært gjennomført fiskebiologiske undersøkelser i de regulerte vassdragene Sima, Osavassdraget (Austdøla og Norddøla), Jondalselva, Øyreselva, Austrepollelva og Bondhuselva i Hardanger. Denne rapporten er rapport for undersøkelser foretatt i 2023, og omfatter gytefisktellinger og ungfiskundersøkelser, samt registrering av vanntemperatur.publishedVersio
The Effects of Predominantly Chemoautotrophic Versus Heterotrophic Biofloc Systems on Nitrifying Bacteria, Planktonic Microorganisms, and Growth of Penaeus vannamei, and Oreochromis niloticus in an Integrated Multitrophic Culture
Full text linkThe aim of this study was to evaluate the effect of predominantly chemoautotrophic and heterotrophic biofloc systems on ammonia-oxidizing bacteria (AOB), nitrite-oxidizing bacteria (NOB), and planktonic microorganisms in an integrated Penaeus vannamei and Oreochromis niloticus integrated multitrophic culture. Shrimp and tilapia were stocked at a density of 400 shrimp m−2 and 45 fish m−3, respectively. The trial consisted of two biofloc treatments, with three replicates each: chemoautotrophic and heterotrophic. The identification and quantification of the planktonic microorganisms (ciliates, flagellates, microalgae, and total bacteria) and nitrifying bacteria were carried out through direct counting and fluorescence in situ hybridization, respectively. At the end of the trial, heterotrophic treatment had resulted in higher total abundance of bacteria. The relative abundance of AOB and NOB in relation to the total abundance was less than 0.1% for both treatments. The system was dominated by flagellates in both treatment groups. The abundance of microalgae and ciliates was higher with chemoautotrophic treatment. After 43 days, the shrimp weights were higher in the chemoautotrophic group, while the final weights of the tilapia were not significantly different between the two treatments. The type of biofloc system (Chemoautotrophic vs. Heterotrophic) did not significantly alter the establishment of AOB and NOB in a Penaeus vannamei and Oreochromis niloticus integrated multitrophic culture. The two treatments proved to be equally efficient for maintaining good water quality, but the chemoautotrophic treatment resulted in better shrimp growth. Thus, our study demonstrated that chemoautotrophic biofloc is a promising approach in integrated multitrophic aquaculturepublishedVersio
CICE on a C-grid: New momentum, stress, and transport schemes for CICEv6.5
Full text linkThis article presents the C-grid implementation of the CICE sea ice model, including the C-grid discretization of the momentum equation, the boundary conditions (BCs), and the modifications to the code required to use the incremental remapping transport scheme. To validate the new C-grid implementation, many numerical experiments were conducted and compared to the B-grid solutions. In idealized experiments, the standard advection method (incremental remapping with C-grid velocities interpolated to the cell corners) leads to a checkerboard pattern. A modal analysis demonstrates that this computational noise originates from the spatial averaging of C-grid velocities at corners. The checkerboard pattern can be eliminated by adjusting the departure regions to match the divergence obtained from the solution of the momentum equation. We refer to this novel approach as the edge flux adjustment (EFA) method. The Cgrid discretization with edge flux adjustment allows for transport in channels that are one grid cell wide– a capability that is not possible with the B-grid discretization nor with the Cgrid and standard remapping advection. Simulation results match the predicted values of a novel analytical solution for one-grid-cell-wide channels.publishedVersio
Habitatkartlegging i Bondalselva i 2021
Full text linkDenne rapporten sammenstiller resultater av en habitatkartlegging utført av NORCE LFI i Bondalsvassdraget i Ørsta kommune våren 2021, med supplerende undersøkelser i perioden 2021-2024. Kartleggingen inkluderte selve Bondalselva (7,5 km), Sledalselva (7,4 km) og Videtjørnelva (4,6 km). Nedre halvdel av Bondalselva er sterkt utrettet og kanalisert, og dette har forringet fiskehabitatet betydelig. Det er bra med skjul for ungfisk, men lite gyteområder og ingen store kulper, De aller fleste sideløp langs Bondalselva er i tillegg avstengt. Sledalselva er derimot lite inngrepspreget, og har store gyteområder i øvre del. Videtjørnelva er forbygd i nedre del, men har mye gyteområder og generelt godt fiskehabitat. Flaskehalsen for fiskeproduksjon i vassdraget er mangel på gyteområder, og da spesielt i nedre halvdel av hovedelven. For å bedre gyteforholdene i vassdraget anbefales det å utvide elveløpet, gjenåpne fire sideløp og å legge ut gytegrus i Bondalselva. I tillegg foreslås det å la kantvegetasjonen vokse opp der denne er fjernet.Habitatkartlegging i Bondalselva i 2021publishedVersio
DBLU - Distriktsvennlig barnehagelærerutdanning
Full text linkRapporten er basert på en evaluering av koordinatorrollen i Distriktsvennlig Barnehagelærerutdanning ved UiA.DBLU - Distriktsvennlig barnehagelærerutdanningpublishedVersio