Diet and food availability for north-east Atlantic minke whales (Balaenoptera acutorostrata), during the summer of 1992     

Haug  Tore; Gjosaeter  Harald; Lindstrom  Ulf; Nilssen  Kjell T 《ICES Journal of Marine Science》1995,52(1):77-86

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Tagging and recapture of Atlantic halibut (Hippoglossus hippoglossus) in Norwegian waters     

Godo  Olav Rune; Haug  Tore 《ICES Journal of Marine Science》1988,44(2):169-179

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Temporal and spatial variability of phytoplankton and chlorophyll a: lessons from the south coast of Norway and the Skagerrak     

Dahl  Einar; Johannessen  Tore 《ICES Journal of Marine Science》1998,55(4):680-687

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Dynamics of dust in a plasma sheath and injection of dust into the plasma sheath above Moon and asteroidal surfaces     

Tore Nitter  Ove Havnes 《Earth, Moon, and Planets》1992,56(1):7-34

We have examined single dust particle dynamics in a plasma sheath near the surface of solid bodies in space, considering conditions which resemble those of planetary system bodies, when photoelectric effect can be neglected. The forces on the dust particles are assumed to be from the electric field in the sheath and from gravitation only. As the dust particles will charge negatively in the sheath, these forces will act in opposite directions and may balance.The charge delay of a moving dust particle is responsible for many of the interesting dynamical properties, and we show that for a stationary plasma, dust motion is unstable to about one Debye length out from the surface of the solid body. This part of the sheath will therefore be devoid of dust particles as they will either fall down, escape completely from the solid body or collect and make damped oscillations at stable positions in the outer part of the sheath. With increasing plasma bulk speed towards the surface, the inner unstable part of the sheath will decrease in thickness.The sources for the dust in the sheath are assumed to be mainly ejecta from meteorites and micrometeorites, but may also, for the smallest solid bodies, be from electrostatic levitation of very small dust particles. We have for different sizes of solid bodies calculated the sizes of ejecta that can be floated in the sheath. For the solar wind plasma, the suspended dust particles range from less than 1 m for the Moon to about 80 m for an asteroid with radius 1 km. These particles create a dust atmosphere.The results in this paper hold when the dust particle density is so low that the charges on the dust particles do not contribute significantly to the total space charge; a higher density will lead to a modification of the sheath.Our calculations show that ejecta below a certain size will be accelerated in the sheath and totally escape from the body even if they have near zero initial vertical velocity, while ejecta above this size will need a much larger velocity to escape. This is especially significant for the small solid bodies (radius of order km and less) which will therefore act as important sources of micronsized dust. This could be of significance for the dust production and the size distribution of dust in planetary ring systems.  相似文献   

Abatement of Greenhouse Gases: Does Location Matter?     

Terje Berntsen  Jan Fuglestvedt  Gunnar Myhre  Frode Stordal  Tore F. Berglen 《Climatic change》2006,74(4):377-411

Today's climate policy is based on the assumption that the location of emissions reductions has no impact on the overall climate effect. However, this may not be the case since reductions of greenhouse gases generally will lead to changes in emissions of short-lived gases and aerosols. Abatement measures may be primarily targeted at reducing CO₂, but may also simultaneously reduce emissions of NO_x, CO, CH₄ and SO₂ and aerosols. Emissions of these species may cause significant additional radiative forcing. We have used a global 3-D chemical transport model and a radiative transfer model to study the impact on climate in terms of radiative forcing for a realistic change in location of the emissions from large-scale sources. Based on an assumed 10% reduction in CO₂ emissions, reductions in the emissions of other species have been estimated. Climate impact for the SRES A1B scenario is compared to two reduction cases, with the main focus on a case with emission reductions between 2010 and 2030, but also a case with sustained emission reductions. The emission reductions are applied to four different regions (Europe, China, South Asia, and South America). In terms of integrated radiative forcing (over 100 yr), the total effect (including only the direct effect of aerosols) is always smaller than for CO₂ alone. Large variations between the regions are found (53–86% of the CO₂ effect). Inclusion of the indirect effects of sulphate aerosols reduces the net effect of measures towards zero. The global temperature responses, calculated with a simple energy balance model, show an initial additional warming of different magnitude between the regions followed by a more uniform reduction in the warming later. A major part of the regional differences can be attributed to differences related to aerosols, while ozone and changes in methane lifetime make relatively small contributions. Emission reductions in a different sector (e.g. transportation instead of large-scale sources) might change this conclusion since the NO_x to SO₂ ratio in the emissions is significantly higher for transportation than for large-scale sources. The total climate effect of abatement measures thus depends on (i) which gases and aerosols are affected by the measure, (ii) the lifetime of the measure implemented, (iii) time horizon over which the effects are considered, and (iv) the chemical, physical and meteorological conditions in the region. There are important policy implications of the results. Equal effects of a measure cannot be assumed if the measure is implemented in a different region and if several gases are affected. Thus, the design of emission reduction measures should be considered thoroughly before implementation.  相似文献   

The impact of shipping on the invasion of alien plants to Norway     

Tore Ouren 《GeoJournal》1978,2(2):123-132

Important agencies responsible for the invasion of alien plants to Norway by means of shipping were ballast thrown ashore from sailing ships and contaminants in imported grain. Most ballast-plants were casuals, which disappeared when the ballast traffic ceased at the time of World War I. Changes in the origin of imported grain are reflected in the grain mill flora.  相似文献   

The geology and petrology of Bouvetøya,south Atlantic Ocean     

Pall Imsland  Jørgen G. Larsen  Tore Prestvik  Ellen M. Sigmond 《Lithos》1977,10(3):213-234

The Quaternary island Bouvetøya is situated near the triple junction on the South Atlantic Ridge. It is the top of a volcano of about 2000 km⁸, evolved beyond the stage of caldera collapse. Basic, intermediate and peralkaline silicic rocks of a transitional rock series are recorded. Major and trace element chemistry, model calculations and petrographic observations do not favour a closed system fractional crystallization from one parent. The rocks may have evolved from slightly different parents by fractional crystallization under varying P,T and P_H2O conditions, or from one parent modified by crustal contamination and/or volatile transfer.  相似文献   

Al-excessive feldspars: a hypothetical model with octahedrally coordinated Al in planar defects     

Tore Torske 《Lithos》1974,7(2):75-79

If AlO₆-octahedra were accidentally included in growing feldspar structures as point defects, they could become ordered on hypothetical (010)_2/4±1/4 crystallographic shear planes and/or collapsed twin boundaries. Such planar defects would consist of ordered arrays of tetrahedral and octahedral sites, and six-coordinated interstitial positions. It is tentatively suggested that Al in excess of the ideal feldspar composition could be accomodated metastably in such planar defects.  相似文献   

The potential of natural ecosystem self-purifying measures for controlling nutrient inputs     

Petter D. Jenssen  Trond M  hlum  Roger Roseth  Bent Braskerud  Nina Syversen  Arnor Nj  s  Tore Krogstad 《Marine pollution bulletin》1994,29(6-12):420-425

Most ecosystems have a certain assimilative capacity regarding plant nutrient or biodegradable organic matter. Knowledge of the metabolizing processes of different ecosystems enable the use of natural systems for pollution abatement from agricultural, domestic and industrial sources. Such ecologically engineered natural systems are often very cost efficient. At the Centre for Soil and Environmental Research (JORDFORSK) studies of degradation processes and the fate of plant nutrients in small streams, ponds, wetlands, vegetative filter strips and soil are being conducted in order to gain experience with and develop self purifying methods. Preliminary results show that denitrification in streams remove only a minor part of the annual nitrogen (N) transport (1–15%), but that this process can remove a considerable part of the N transport during summer. Constructed ponds and wetlands in streams draining agricultural areas showed 10–56% retention of soil particles, 23–40% of phosphorous (P) and 5–13% of N. Narrow ponds had a higher efficiency than wide ponds per unit surface area. Short-term experiments with vegetative strips treating agricultural runoff show a sediment removal of over 95%, a P removal from 80–90% and N removal between 60 and 75%. A multistage subsurface constructed wetland treating domestic waste-water removed an average of 97% P, 91% BOD, 80% of suspended solids, 55% N and 99.9% E. coli over the first 18 months of operation. Preliminary results from a multistage plant with constructed ponds and wetlands treating landfill leachate show high treatment efficiency for the same parameters. A rapid infiltration plant in northern Norway showed an average removal of 99% P, 90% COD and 73% N after 4 years of operation. These results show that self purifying measures offer potential for design of pollution abatement systems for agricultural as well as domestic purposes in the Norwegian climate.  相似文献   

The fate and weathering of surface oil from the bravo blowout     

Tore Audunson 《Marine environmental research》1980,3(1):35-61

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