The total area of the Barents Sea is 1.4 million square kilometres with an average water depth of 230m. The water volume is 322 000km3 .
The continental shelf is narrowest just north of the Lofoten Archipelago where the width is approximately 30km
At approximately 17°E the shelf turns northward, and it approximately follows this longitude to Svalbard. West of the continental slope the water depth is 2000m to 3000m. The depth on the Norwegian continental shelf varies between 200 and 500m, except for the area southeast of Svalbard, where the depth is less than 100m, and the banks in the Barents Sea and offshore the Norwegian coast where the depth ranges between 100m and 200m.
On the Russian shelf the water depth is generally between 200m and 300m, decreasing to 100m north of Cape Kanin and west of Novaya Zemlya. In the Pechora Sea the water depth decreases eastward and reaches a minimum water depth of approximately 20m in the eastern part.
Polar lows
A polar low is a low pressure phenomenon which is normally generated during situations with outbreaks of cold arctic air over the sea. Energy to drive the system is provided by heat and moisture transferred from the sea, and by energy transformations within the atmosphere.
During the passage of a polar low the wind speed typically increases to storm force in a short time (1/2 - 2 hours) with changing wind direction. Heavy snowfall takes place, and the visibility is poor. Sometimes high waves accompany the polar low, and they may occur simultaneously with the onset of the strong wind.
All Norwegian coastal areas are affected by polar lows, with a maximum between Bjørnøya and Northern Norway.
Waves
Most storms in the Barents sea are dominated by south-westerly weather, which is the sector with the longest wave generating fetches. Atlantic swell has also been tracked into the Barents Sea arriving at Sentralbanken about 24 hours after passing through the area off mid-Norway. The energy levels associated with this swell are generally significantly lower than further south. The Hs/Tp scatter table indicates the presence of low frequency energy that may significantly impact floating structures.
There is little variation in the mean significant wave height in the western Barents Sea, however the wave height decreases eastward. The highest significant wave heights observed at the AMI location is 12.7m occurring on 31 October 1997 during south westerly wind caused by a rapid developing low pressure moving from Jan Mayen into the Barents Sea. The highest significant wave height at Nordkappbanken of 13.6m was recorded during a severe storm on 3 January 1993.
The ice edge also has an important influence on the wave climate in the northern and eastern areas. At a given location the fetch lengths will increase in summer from sectors subject to winter icing. Therefore the resultant wave heights will be greater in summer than winter. In the marginal ice zone itself the presence of ice will tend to damp out and reflect some energy arriving from the off-ice sector such that the wave height will decrease further from the ice edge. The attenuation of wave energy is less noticeable in long period waves, which will penetrate farther than short period waves.
Currents
The Norwegian Coastal Current follows the coastline of Norway into the Barents Sea. The highest velocities are found along the slope. At the banks, however, the velocities are reduced by bottom friction.
A clock-wise vortex is located at Tromsøflaket. Outside West Finnmark the Norwegian Atlantic Current splits into two branches. The North Cape Current runs eastwards along the Norwegian Coast into the Barents Sea, and can be clearly identified to about 30°E. The mean velocity in this current is 0.10-0.12 ms-1. Further east, the current splits into several branches, but an essential part of the current follows the Russian Coast and turns north-west along the western coast of Novaya Zemlja.
The other branch, called the West Spitsbergen Current, follows the slope northwards and runs along the western coast of West Spitsbergen, where it meets Polar Waters and turns southwards into the Greenland Sea.
The Bear Island Current is a narrow cold current running in a west to south-west direction towards the Norwegian Sea. It comes from the northern parts of the Barents Sea and follows the southern slope of the Bear Island Bank. The current turns around Bjørnøya and then runs northwards parallel with the West Spitsbergen Current. The two currents are gradually mixed. The Bear Island Currents is rather small and narrow, and may seem insignificant. However, it frequently carries ice south of Bjørnøya.
North of the Bear Island Current, and parallel to this, the East Spitsbergen Current runs between Hopen and the Edge Island. It turns at the South Cape, and flows northwards along the West coast of Spitsbergen, inside the West Spitsbergen Current. This current carries polar or arctic water with temperatures below 0°C and low salinities. Early in the summer, this flow often carries ice along the coast.
The tidal wave moves eastward into the Barents Sea. The amplitude increases eastward along the Norwegian coast and the value of the major tidal component (M2) in Vadsø in the eastern part of Finnmark, is 1.09m. The amplitude increases further eastward along the Russian coast, and the M2 constituent reaches a maximum north of the White Sea of 1.30m. The M2 constituent then decreases eastward and in the Petchora Sea the amplitude is 20 cm.
An amphodromic point is situated southeast of Svalbard and one west of Novaja Zemlja. The amplitude in the northern part of the Barents Sea is therefore relatively small with an M2 amplitude less than 50 cm.
Sea Ice
The Norwegian coast is ice free throughout the year, while the northernmost part of the Barents Sea is ice free only in July - September and some years there is ice all the year around.
There is a large variation of the ice conditions in the Barents Sea. During the winter the ice grows from the coast of Svalbard and over the shallow part of the shelf. Heavy, warmer water, which flows northward and eastward from the Norwegian Sea, fills the deeper part of the ocean, and hence the maximum distribution of the ice usually coincides with the limits between the shallower and deeper part of the ocean. During calm conditions, the ice edge clearly reflects the bottom topography.
The ice reaches its maximum southward extension in March, and in the eastern part it reaches the Russian mainland. The remaining part of the Barents Sea is usually ice free south of 75°N. The maximum northward limit of the ice edge is found just west of Svalbard. Here the ice edge forms a well-defined bay, Svalbardbukta, which is created by warm water flowing northward along the continental slope.
The ice edge reaches its maximum northward extension in August. The spatial variation is not as large as during the winter. The ice edge in August almost follows the 80°N latitude, with the maximum southward position at the east coast of Svalbard.
Icebergs
Icebergs drifting in the Barents Sea originate from the glaciers at Svalbard and Franz Josef Land. They are usually rather smooth, less than 100m thick and with a horizontal extension of maximum 300-400m. A number of giant icebergs have, however, been observed. In 1881 one iceberg was observed close to the Norwegian coast as far south as 70°N, and in 1929 twenty icebergs were observed off the east coast of Finnmark. Apart from these instances no icebergs have been observed south of 72.5°N and west 32°E.
Sea Spray Icing
Wind speed and air temperature are the most important parameters affecting sea spray icing intensity. The wind speed has an obvious effect on the generation of sea spray. In addition it influences the cooling rate of the airborne droplets. The intensity of icing will steadily increase with decreasing air temperature from about -2°C and down to the lowest temperature to be anticipated during offshore operations.
The influence of sea surface temperature on the icing intensity is less than for wind speed and air temperature. It is of importance in the initial stage of icing, i.e. at moderate wind speeds and air temperature down to -5°C, but has a marginal influence at high icing intensities.
Protected areas on Bjornoya5
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