scholarly journals Analysis of instability and mesoscale motion off southern Norway

2006 ◽  
Vol 111 (C8) ◽  
Author(s):  
I. Fossum
Keyword(s):  
Southern Norway ◽  
Mesoscale Motion

Structure and dynamics of a high mountain wetland bird community in southern Norway: An 18-year study of waders and gulls

2007 ◽  
Vol 30 (0) ◽  
pp. 4 ◽  
Author(s):  
Eivind Østbye ◽  
Olav Hogstad ◽  
Kjartan Østbye ◽  
Leif Lien ◽  
Erik Framstad ◽  
...  
Keyword(s):  
Bird Community ◽  
High Mountain ◽  
Structure And Dynamics ◽  
Southern Norway

Improving Runoff Simulations using Satellite-observed Time-series of Snow Covered Area

2003 ◽  
Vol 34 (4) ◽  
pp. 281-294 ◽  
Author(s):  
R.V. Engeset ◽  
H-C. Udnæs ◽  
T. Guneriussen ◽  
H. Koren ◽  
E. Malnes ◽  
...  
Keyword(s):  
Time Series ◽  
Radar Sensors ◽  
Noaa Avhrr ◽  
Runoff Forecasting ◽  
Snow Covered Area ◽  
Covered Area ◽  
Satellite Sensors ◽  
Major Floods ◽  
Using Data ◽  
Southern Norway

Snowmelt can be a significant contributor to major floods, and hence updated snow information is very important to flood forecasting services. This study assesses whether operational runoff simulations could be improved by applying satellite-derived snow covered area (SCA) from both optical and radar sensors. Currently the HBV model is used for runoff forecasting in Norway, and satellite-observed SCA is used qualitatively but not directly in the model. Three catchments in southern Norway are studied using data from 1995 to 2002. The results show that satellite-observed SCA can be used to detect when the models do not simulate the snow reservoir correctly. Detecting errors early in the snowmelt season will help the forecasting services to update and correct the models before possible damaging floods. The method requires model calibration against SCA as well as runoff. Time-series from the satellite sensors NOAA AVHRR and ERS SAR are used. Of these, AVHRR shows good correlation with the simulated SCA, and SAR less so. Comparison of simultaneous data from AVHRR, SAR and Landsat ETM+ for May 2000 shows good inter-correlation. Of a total satellite-observed area of 1,088 km2, AVHRR observed a SCA of 823 km2 and SAR 720 km2, as compared to 889 km2 using ETM+.

Temperature and Flow Conditions in a Reservoir with a Submerged Outlet Tunnel During the Winter Period

1986 ◽  
Vol 17 (4-5) ◽  
pp. 399-406
Author(s):  
Arve M. Tvede
Keyword(s):  
Strong Influence ◽  
Winter Season ◽  
Circulation Pattern ◽  
Electricity Production ◽  
Winter Period ◽  
Flow Conditions ◽  
Power Station ◽  
Reservoir Water ◽  
Southern Norway ◽  
Tunnel Depth

The reservoir Sundsbarmvatn, in Southern Norway, is used for electricity production from November to May. Sundsbarmvatn has two main basins. Water from the upper basin, Mannerosfjorden, flows into the lower basin, Gullnesfjorden. The two basins are separated by a narrow sound with a sill. The regulation interval for Sundsbarmvatn is 612-574 m a.s.l., but the sill prevents Mannerosfjorden from being lowered below 580 m a.s.l. The water intake in Gullnesfjorden is 571 m a.s.l. The water temperature conditions has been studied during two winters when the reservoir water was released. This study shows that a marked thermocline was gradually developed at the depth of withdrawal in Gullnesfjorden. In the epilimnion layer the temperature is gradually lowered through the winter, but in the hypolimnion layer the temperature seems to stay constant through the winter. In Mannerosfjorden, however, we find no clear thermocline at the end of the winter. The remaining water was relatively warm with temperatures mainly above 3 °C. The sill between the two basins seems to have a strong influence on which depth the water is flowing out of Mannerosfjorden and hence on the temperature and circulation pattern in Gullnesfjorden. At the end of the winter season this flow is strengthening and initiates a homogeneous flow layer in Gullnesfjorden. This layer is dipping downwards towards the outlet tunnel. For this reason the temperature of the water leaving the power station is 0.4-1.2 °C colder than the hypolimnion temperature in the reservoir at the tunnel depth.

scholarly journals National Trends in Cycling in Light of the Norwegian Bike Traffic Index

2021 ◽  
Vol 18 (12) ◽  
pp. 6198
Author(s):  
Solveig Nordengen ◽  
Lars Bo Andersen ◽  
Amund Riiser ◽  
Ane K. Solbraa
Keyword(s):  
Urban Areas ◽  
Active Transportation ◽  
Monitoring Systems ◽  
Geographical Differences ◽  
Southern Norway ◽  
Associated Risk Factors ◽  
National Trends ◽  
International Strategies ◽  
Nonsignificant Decrease ◽  
Walking For Transportation

National and international strategies and recommendations are intended to increase physical activity in the general population. Active transportation is included in interdisciplinary strategies to meet these recommendations. Cycling seems to be more health enhancing than walking for transportation since cycling seems to reduce the risk of cardiovascular disease and associated risk factors. Furthermore, the health benefits of cycling are proven to outrun the risk of injuries and mortality. Politicians seem to approve costly infrastructure strategies to increase the amount of cycling in the population to improve public health and shift to more sustainable travel habits. A linear relationship between cycle-friendly infrastructure and the amount of commuter cycling has been demonstrated. However, in Norway and on a global level, there is a lack of robust evaluations of actions and sensitive monitoring systems to observe possible change. Therefore, we aimed to develop the Norwegian bike traffic index and describe the national, regional, and local trends in counted cycle trips. We used a transparent methodology so that the index can be used, developed, and adapted in other countries. We included 89 stationary counters from the whole country. Counters monitored cycling from 2018 onward. The index is organized at local, regional, and national levels. Furthermore, the index is adjusted for population density at the counter level and presented as ratio of counted cycle trips, comparing 2018 to subsequent years. The index is presented as a percentage change with 95% confidence intervals. In Norway, counted cycle trips increased by 11% from 2018 (100, 100–100) to 2020 (111.0, 106.2–115.1), with large geographical differences. In Southern Norway, there was a significant increase of 23%, and in Northern Norway, there was a nonsignificant decrease by 8% from 2018 to 2020. The indices may indicate possible related effects of local to national cycling strategies and how the COVID-19 pandemic has affected Norwegian travel habits in urban areas.

scholarly journals Activity patterns of the soprano pipistrelle Pipistrellus pygmaeus throughout the year in southern Norway

BMC Zoology ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Karl Frafjord
Keyword(s):  
Activity Patterns ◽  
Late Summer ◽  
Active Season ◽  
Male Song ◽  
Oceanic Climate ◽  
Social Calls ◽  
Southern Norway ◽  
Winter Hibernation ◽  
Small Valley ◽  
Made In

Abstract Background Most temperate bats are regular hibernators in the winter. Knowledge about the length of their active season and how they adjust their nightly activity throughout the season, is critical to conservation. The characteristics of these are likely to vary with climate as well as latitude. This study investigated the flight activity of the soprano pipistrelle Pipistrellus pygmaeus in Frafjord, a small valley in the south-western corner of Norway (58° 50′N 6° 18′E) with an oceanic climate. Results Activity was recorded with an ultrasound recorder throughout April 2018 to June 2019 at one site, with supplemental recordings in March to June 2020, i.e., covering all months of the year. Recordings at other nearby sites were made in the summers (June–August) of 2016, 2017, 2019 and 2020, as well as some of the last days in December 2019 to the first days of January 2020. Overall, soprano pipistrelles were recorded flying in all months of the year, but very few in December–March. Regular activity was recorded from late April or early May until late October, and some recordings were also made in November. The highest numbers of recordings were made in August and September. Social calls, i.e. male song flights, were recorded from April to November, with the vast majority in August and September. Nearly all recordings were made between sunset and sunrise. Conclusions The soprano pipistrelle in this region showed regular activity through 6–7 months of the year. It adjusted its activity to the changing night length throughout the year, closely following sunset and sunrise. It was rarely recorded flying before sunset and almost never after sunrise. Most activity was recorded in the middle of the night, and social calls also followed this trend closely. Harems in late summer and autumn were confirmed in a bat box, which was also used for winter hibernation.

scholarly journals Anomalous azimuthal variations with 360° periodicity of Rayleigh phase velocities observed in Scandinavia

2020 ◽  
Vol 224 (3) ◽  
pp. 1684-1704
Author(s):  
Alexandra Mauerberger ◽  
Valérie Maupin ◽  
Ólafur Gudmundsson ◽  
Frederik Tilmann
Keyword(s):  
Seismic Anisotropy ◽  
Broad Band ◽  
Shear Velocity ◽  
Velocity Variation ◽  
The South ◽  
Study Region ◽  
Lithospheric Thickness ◽  
Phase Velocities ◽  
The North ◽  
Southern Norway

SUMMARY We use the recently deployed ScanArray network of broad-band stations covering most of Norway and Sweden as well as parts of Finland to analyse the propagation of Rayleigh waves in Scandinavia. Applying an array beamforming technique to teleseismic records from ScanArray and permanent stations in the study region, in total 159 stations with a typical station distance of about 70 km, we obtain phase velocities for three subregions, which collectively cover most of Scandinavia (excluding southern Norway). The average phase dispersion curves are similar for all three subregions. They resemble the dispersion previously observed for the South Baltic craton and are about 1 per cent slower than the North Baltic shield phase velocities for periods between 40 and 80 s. However, a remarkable sin(1θ) phase velocity variation with azimuth is observed for periods >35 s with a 5 per cent deviation between the maximum and minimum velocities, more than the overall lateral variation in average velocity. Such a variation, which is incompatible with seismic anisotropy, occurs in northern Scandinavia and southern Norway/Sweden but not in the central study area. The maximum and minimum velocities were measured for backazimuths of 120° and 300°, respectively. These directions are perpendicular to a step in the lithosphere–asthenosphere boundary (LAB) inferred by previous studies in southern Norway/Sweden, suggesting a relation to large lithospheric heterogeneity. In order to test this hypothesis, we carried out 2-D full-waveform modeling of Rayleigh wave propagation in synthetic models which incorporate a steep gradient in the LAB in combination with a pronounced reduction in the shear velocity below the LAB. This setup reproduces the observations qualitatively, and results in higher phase velocities for propagation in the direction of shallowing LAB, and lower ones for propagation in the direction of deepening LAB, probably due to the interference of forward scattered and reflected surface wave energy with the fundamental mode. Therefore, the reduction in lithospheric thickness towards southern Norway in the south, and towards the Atlantic ocean in the north provide a plausible explanation for the observed azimuthal variations.

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