Oceanographic conditions on the Weddell Sea Shelf during the German Antarctic Expedition 1979/80     

ARNE FOLDVIK  TOR GAMMELSRøD  NORALF SLOTSVIK  TOR TøRRESEN 《Polar research》1985,3(2):209-226

Hydrographic (CTD), current and water level measurements obtained in the vicinity of the floating Ronne and Filchner Ice Shelves are presented. The distribution of Western Shelf Water (S > 34.7) and Ice Shelf Water (T<−1.9°C) are discussed. The general circulation in the area seems to consist of two large cyclonic gyres, one in the Filchner Depression and one north of the Ronne Ice Shelf. Each gyre shows a'warm'(T 1°C) southgoing flow of Modified Weddell Deep Water and a cold northward flow of Ice Shelf Water. The mean surface current was found to be 8cm/s towards the north-west along the barrier. The mean flow below the ice shelf shows significant components normal to the barrier, and mixing seems to be very efficient here. Well mixed layers down to more than 150 m were observed. North of Berkner Island the water level shows a typical mixed tide with tidal range ∼3m. In the tidal currents the semidiurnal constituents dominate (∼30cm/s) and with the largest current components normal to the barrier.  相似文献   

Hydrographic observations from the Weddell Sea during the Norwegian Antarctic Research Expedition 1976/77   总被引：1，自引：0，他引：1  

ARNE FOLDVIK  TOR GAMMELSRøD  TOR TøRRESEN 《Polar research》1985,3(2):177-193

CTD observations from the southern Weddell Sea in 1977 show that Ice Shelf Water originating under the floating Filchner Ice Shelf overflows at the sill of the Filchner Depression and can be identified on the continental slope at more than 2000m depth. Intrusions of Weddell Deep Water upon the shelf are especially noticeable in the region of dense shelf water outflow and are possibly driven by the outflow. Anomalous low core temperature of Weddell Deep Water is probably related to winter convection in the Weddell Polynya. Anomalous CTD stations at the periphery of the 1976 winter polynya region indicate that deep convection phenomena, as reported by Gordon (1978), are perhaps quite common. The observations indicate that double diffusive convection is important for vertical heat transport in the central Weddell Sea.  相似文献   

Synergistic effects of an oil dispersant and low temperature on the freezing tolerance and solute concentrations of the blue mussel (Mytilus edulis L.)     

ARNE VOLLAN AARSET  KARL ERIK ZACHARIASSEN 《Polar research》1983,1(3):223-230

Exposure of blue mussels ( Mytilus edulis L.) to an oil dispersant in increasing concentrations caused increased degree of injury in the mussels. The oil dispersant seemed to affect mechanisms responsible for the distribution of inorganic ions (Na⁺, K⁺, CI⁻) and free amino acids across the cell membranes. The dispersant caused a marked reduction in the ability of the mussels to survive freezing at −10°C. Freezing also caused more pronounced alterations in the transmembrane ionic distributions observed following exposure to the dispersant. This may indicate that the injuries caused by freezing are qualitatively the same as those caused by exposure to the dispersant alone, but brought into more extreme conditions. Thus, freezing appears to potentiate the effect of environmental pollutions by concentrating them in the fluid fraction of the frozen body fluids.  相似文献   

The influence of palaeosalinity, grain size distribution and clay minerals on the content of B, Li and Rb in Quaternary sediments from Eastern Jutland, Denmark     

ARNE VILLUMSEN  OLE BJØRSLEV NIELSEN 《Sedimentology》1976,23(6):845-855

Bulk sample analysis of Late- and Postglacial sediments from the Randers fjord area, Eastern Jutland, seem to indicate a relationship between palaeosalinity and B, Li and Rb contents determined on weak acid extracts of the sediment. Investigations of different size fractions, grain size distribution, and of clay minerals show, however, that variations in palaeosalinity as determined by palaeontological methods in this case have no direct influence on the chemistry. The variation of Li and Rb is related to variation in grain size, while the B variation seems to be related to the content of montmorillonite in the clay fraction.  相似文献   

Thermal hysteresis antifreeze agents in fishes from Spitsbergen waters     

JOHN-PEDER DENSTAD  TORE AUNAAS  JAN FREDRIK BORSETH  ARNE VOLLAN AARSET  KARL ERIK ZACHARIASSEN 《Polar research》1987,5(2):171-174

The occurrence of macromolecular antifreeze agents (so-called Thermal Hysteresis Factors) in blood plasma of fishes from Spitsbergen waters was investigated in August 1983, October 1984, and January 1986.
Thermal hysteresis was found in the plasma of three species of Spitsbergen fishes: shorthorn sculpin (Myoxocephalus scorpius) , polar cod (Boreogadus saida) , and sea snail (Liparis liparis) . This is the first time thermal hysteresis is reported from the sea snail. Seasonal changes in the amount of thermal hysteresis were observed in blood plasma of the shorthorn sculpin and the sea snail.
With the exception of the polar cod, blood plasma of deep water fishes displays no thermal hysteresis. The reason for this is probably that the polar cod also occurs in shallow ice laden sea water, where an'antifreeze'would be needed to protect against inoculative freezing.
No thermal hysteresis was observed in blood plasma of the saithe (Pollachius virens) , despite the fact that the saithe was observed swimming in ice laden sea water at a temperature of -1 to – 1.5°C under natural conditions, and was rapidly killed when it came into contact with ice in the laboratory. It is not known how the saithe survives in ice laden water under natural conditions.  相似文献