Polar Research

Published by Co-Action Publishing
Online ISSN: 1751-8369
Publications
Article
The stratigraphic importance of fossils is never more apparent than in attempts to unravel the complexities of metamorphic terrains. The age and stratigraphic relationships of the thick metasedimentary and metavolcanic succession of Prins Karls Forland, western Svalbard, have been the subject of investigation and debate since the early part of this century (Hoel 1914; Craig 1916; Tyrrel 1924), and sharply different interpretations have been proposed (e.g. Harland et al. 1979; Hjelle et al. 1979). Until now, such interpretations have been unconstrained by palaeontological data, an understandable consequence of the metamorphic alteration undergone by these rocks. In this paper, we report the discovery of stratigraphically useful microfossils preserved in chert nodules from carbonaceous, dolomitic shales on northern Prins Karls Forland. These fossils have significant implications for the stratigraphic and structural interpretation of Forland metasediments, as well as for the more general problem of palaeontological prospecting in severely deformed and metamorphosed terrains, including those characteristic of the Archean Eon.
 
Article
Novaya Zemlya was covered by the eastern part of the Barents–Kara ice sheet during the glacial maximum of marine isotope stage 2 (MIS 2). We obtained 14C ages on 37 samples of mollusc shells from various sites on the islands. Most samples yielded ages in the range of 48–26 14C Ky. Such old samples are sensitive to contamination by young 14C, and therefore their reliability was assessed using replicate analyses and amino acid geochronology. The extent of aspartic acid racemization (Asp D/L) indicates that many of the 14C ages are correct, whereas some are minimum ages only. The results indicate that a substantial part of Novaya Zemlya was ice-free about 35–27 14C Kya, and probably even earlier. Corresponding shorelines up to >140 m a.s.l. indicate a large Barents–Kara ice sheet during early MIS 3. These results are consistent with findings from Svalbard and northern Russia: in both places a large MIS 4/3 Barents–Kara ice sheet is postulated to have retreated about 50 Kya, followed by an ice-free interstadial that lasted until up to ca. 25 Kya. The duration of the MIS 2 glaciation in Novaya Zemlya was calculated by applying the D/L values to a kinetic equation for Asp racemization. This indicates that the islands were ice covered for less than 3000 years if the basal temperature was 0oC, and for less than 10 000 years if it was −5oC.
 
Article
This note reports the occurrence of two generations of 14C dated raised beach deposits at Pricepynten. southern Prins Karls Forland, western Svalbard, dated to < 12 Kya and >30 Kya. In addition two new 14C ages of ca. 9.2 and 1.8 Ky are presented from Myrilus eclulis and a buried peat deposit, respectively.
 
Article
To compare north and south polar marine paleoenvironments over the last 30,000 years, comparable chronological (radiocarbon) records must be developed and refined. Many areas in the polar regions do not preserve marine carbonates (foraminifera, mollusks), and thus age determinations, of necessity, are based on the acid-insoluble organic (AIO) fraction of the sediment. Although AIO ages are problematic and rarely used in the Arctic, they provide reasonable and consistent chronologies for the Ross Sea, Antarctica. AIO dates are meaningful in the Ross Sea because there are relatively high levels of productivity, good preservation of marine biogenic material in the sediment, and little input of terrigenous sediment and old/dead carbon. Event stratigraphy based upon proxy records of biogenic silica and δ13C can be used to assess the reliability of the AIO dates and surface age corrections. Reconstructed time-series of changes in the biogenic silica content of cores from the western Ross Sea show apparent similarities with the ‘classic’deglacial climate sequence of the northern North Atlantic. Once the absolute ages of the antarctic AIO dates are constrained by independently dated records to validate surface age corrections, it will be possible to directly compare the timing of events such as ice-rafting events in the sedimentary record.
 
Article
Amazing organogenic deposits were encountered within the terminal moraine zone of Renardbreen, north-western part of Wedel Jarlsberg Land. Pollen analyses and ,14C dating locate the deposits at the Middle Late Subatlantic transition. The position of these deposits indicates possible glacial advances 3,500-2,000 years BP and during the Little Ice Age, respectively. Remnants of human activity at least as old as the 9th century were also found within organogenic deposits.
 
Article
In the spring of 1904, during the Ziegler Polar Expedition led by Anthony Fiala, Sigurd B. Myhre, a Norwegian from Trondheim who served on-board the expedition ship America as a fireman, fell ill and died. The papers of Dr George Shorkley, surgeon to the Ziegler Polar Expedition, contain hints that Myhre may have died from causes other than natural causes.
 
Article
Pro Mare, the Norwegian Research Program for Marine Arctic Ecology, began in 1984 and was concluded in 1989. The aim of the program was to increase our understanding of how pelagic ecosystems function in the Arctic seas, thereby improving the basis for government decision-making as well as elevating scientific competence both with respect to fish stock management and for evaluation of the effects of pollution. The program gave priority to longterm research on systems ecology, with some emphasis on physiological ecology. It accordingly operated in the border zone between pure and applied research with emphasis in terms of methodology on the former. Pro Mare focused on the Barents Sea and the adjacent coastal waters of Svalbard.
 
Article
In June 1986- 42 young Arctic cod were caught in ice-covered waters of the Barents sea with dip-nets by scuba divers. From August to June 1987 the fish were kept at -PC and fed on frozen shrimp (Pandalus borealis). Length and weight were measured monthly. A fast weight increment of about 0.7% per day was observed in the autumn (Sept.-Nov.). In the winter (Jan.-Feb), the growth rate declined to 0.05% per day. However, daily food intake only decreased by 50% during these winter months. Since the fish were exposed to constant illumination in the aquarium, this growth experiment indicates that something else than light has a significant influence on growth in Arctic cod.
 
Article
This study was conducted in Kongsfjorden, Svalbard, from mid-March through April 1984. Local Greenland sled dogs were used to locate subnivean ringed seal lairs. A total of 90 lairs were found and excavated. These constituted 28 lairs classified as birth lairs, 22 as tiggak (rutting male) lairs, and 40 which could not be classified. The first birth lair was found on 24 March. There was significantly more snow covering birth lairs than tiggak lairs, and birth lairs were also shown to be significantly larger than tiggak lairs. The positions of the lairs were plotted on a map, and distances between neighbouring seal lairs were used as an indicator of territorial size. Arctic foxes had attacked 19 lairs and 6 of these had resulted in a kill (32%). Polar bears had attacked 13 lairs with one kill (8%).
 
Article
This paper outlines the results of stable isotope (δD-δ18O) analysis of snow and glacier ice undertaken as part of a larger study concerning structural glaciology, debris entrainment and debris transport patterns at Midtre Lovénbreen, Svalbard. Samples of fresh snow were collected from the glacier surface in spring 1999 and samples of surface glacier ice and basal ice samples were collected in summer 1999. When plotted on bivariate co-isotopic diagrams (δD-δ18O), the slopes obtained for snow and unmodified glacier ice (6.4 and 6.9, respectively) are less steep than those for the basal ice layer and transverse ice layers on the ice surface (7.6 and 7.7, respectively). The difference in the slope of these lines is not statistically significant at the sample size (50) used in this study. The results indicate that although stable isotope analysis clearly has potential for studies of debris entrainment, transport and structural glaciology, difficulties remain with applying this technique. It is therefore not possible to apply these isotopic techniques to ice facies of unknown origins. In particular, large sample numbers are required to establish statistical differences and high-resolution sampling of specific ice facies may be necessary to establish isotopic differences.
 
Article
Data obtained during the last 20 years from selected hydrographic stations throughout the Arctic Ocean basins and at the continental slopes and northern parts of the surrounding shelf seas are examined to estimate the contribution of Atlantic water to the upper part of the Arctic Ocean water column, and to follow the circulation of the Atlantic derived halocline waters around the Arctic Ocean basins. A substantial fraction of the Atlantic water entering the Arctic Ocean in the two inflow branches, the Fram Strait branch and the Barents Sea branch, is transformed into less dense waters. The inflow through Fram Strait encounters and melts sea ice. Its upper part becomes less saline, and in winter, ice formation homogenizes this low salinity upper part into a winter mixed layer, which follows the boundary flow eastward. The inflow over the Barents Sea mainly becomes colder, less saline and denser due to cooling and net precipitation, but melting of sea ice also here creates a less dense upper layer, which is subsequently homogenized by haline convection. Both these components enter the Nansen Basin via the St. Anna Trough and flow eastward along the Siberian continental slope. A third component of the Barents Sea inflow, mainly comprising Norwegian Coastal Current water, remains on the shelf, where it absorbs the runoff from the large Siberian rivers and evolves into low salinity shelf water. This part continues as far east as the Laptev Sea before a major inflow to the deep Arctic Ocean basins occurs. Winter convection, which in most of the Nansen Basin extends to the Atlantic layer, then becomes limited to the injected low salinity shelf water, and the more saline upper layers of the Fram Strait and the Barents Sea branches are transformed into halocline waters. The Fram Strait branch supplies the halocline water of the Amundsen, Makarov and part of the Canada basins, while the upper part of the Barents Sea branch, initially confined to the Siberian continental slope, becomes the main source of the lower halocline below the Pacific water in the Canada Basin beyond the Chukchi Cap. Less dense Pacific water close to the North American continent prevents the Atlantic derived upper layers from flowing through the Canadian Arctic Archipelago and their main exit is Fram Strait. Only some of the Barents Sea branch halocline water passes through Nares Strait and may occasionally renew the deep and bottom waters of Baffin Bay.
 
Article
Three observational data sets are used to construct a continuous record (1850-2001) of April ice edge position in the Barents Sea: two sets of Norwegian ice charts (one from 1850 to 1949 and the other from 1966 to 2001) and Soviet aircraft reconnaissance ice extent charts from 1950 to 1966. The 152-year April ice extent series is subdivided into three sub-periods: 1850-1899, 1900-1949 and 1950-2001. For each of these study sub-periods, a mean April ice edge and a set of anomalies (differences in position between a given April and the mean April ice edge) are computed. The calculations show the mean ice edge position retreated north-eastward over the 152-year period, with the greater retreat seen in the changes from the 1850-1899 sub-period to the 1900-1949 sub-period. The distribution of the standard deviation of the ice edge anomaly over the linear distance along the mean ice edge shows no substantial difference between any of the three periods of the study. Within each study period, the maximum variation is observed in the sector bounded by the 25°E and 49° E meridians, which covers the main pathway of the warmer water flow from the Norwegian Sea.
 
Article
Age determinations for rock samples collected by Fridtjof Nansen during his trans-Arctic expedition from 1893-1896 have yielded additional information on the tectonic chronology of the Arctic Basin. The data suggest pulses of volcanic activity in the Frans Josef Land Archipelago with approximate averages of 120 ma and 135 ma. These ages are consistent with postulated opening dates for the western Arctic and thus suggest that initial volcanism affected the entire Arctic margin.
 
Article
This next paper in Polar Research's series of not-formally-reviewed biographical/historical articles comes to us from anthropologist Pete Capelotti, who specializes in the history of exploration. In 1993, he conducted archaeological research on the base camps of the Andrée and Wellman polar balloon expeditions at Virgohamna, Danskøya, Svalbard. In this account of Walter Wellman's attempt to reach the North Pole from Franz Josef Land in 1898-99, he examines the lone success in that effort, when one American and four Norwegians discovered and explored the last large island in the archipelago.
 
Article
The history of lighter-than-air operations in the Arctic between 1896 and 1930 has focused almost exclusively upon four expeditions. These are the balloon voyage of the Swede Salomon Andrée in 1896–97, and the dirigible expeditions of the American Walter Wellman in 1906–09, the Norwegian Roald Amundsen with the Italian Umberto Nobile in 1926 and the Nobile expedition of 1928. Largely invisible in this lineage are the aeronautical operations of the Baldwin–Ziegler Polar Expedition on Alger Island in the Franz Josef Land Archipelago in 1902. This article traces expedition leader Evelyn Briggs Baldwin's interest in aeronautical exploration in the Arctic, which began early in life, led to a failed attempt to join Andrée in 1897 and culminated in his use of message buoys attached to balloons in June 1902. These operations, the fate of its balloon buoys and the historical archaeology of Baldwin's operational bases in Franz Josef Land and north-east Greenland are examined. Baldwin's poor planning and bad luck with ice conditions around Franz Josef Land caused him to use his balloon buoys not to reach northwards to the pole, but to send relief messages southwards towards civilization. Like the other polar aeronautical expeditions, Baldwin's left behind a significant archaeological assemblage that continues to provide evidence for the material analysis of the history of polar exploration.
 
Article
The following contribution, by film researchers Jan Anders Diesen and Neil Fulton, is the second piece about Walter Wellman in this issue. Whereas Capelotti et al. (this issue) focus on technical aspects of Wellman’s aborted bid for the North Pole in 1906, Diesen and Fulton look at the media hype surrounding the event. They also describe an obscure short film that includes scenes of Wellman in Svalbard in 1906. Although Wellman’s credentials as a polar explorer can be questioned, there is no doubt that he excelled at publicizing his ambitious schemes to the world. —The editor
 
Article
Just over a century ago, the American journalist Walter Wellman first tried to reach the North Pole by airship. Despite the hoopla that surrounded the expedition, it was a fiasco and the attempt became a quirky and somewhat obscure episode in the history of polar exploration. In this issue of Polar Research, we present two complementary contributions about this event. The first paper, below, is a collaboration between Penn State University Abington College archaeologist P. J. Capelotti, engineer and airship historian Herman Van Dyk and Swiss aeronautical historian Jean-Claude Cailliez. It presents new data on the initial operations of Wellman's attempt to reach the pole in 1906.
 
Article
A small mammal collection from the Kolyma region in northeastern Siberia collected by the Norwegian trapper and naturalist Johan Koren between 1915 and 1917 comprises 152 specimens of 17 species. The collection was brought to Norway with Roald Amundsen's “Maud” expedition through the Northeast Passage and has been held by the Zoological Museum, University of Oslo.When comparing the collection with the current distribution of small mammals in the region, it is not possible to detect changes in the small mammal fauna. As several species which are common today are missing in the collection, the collection apparently does not give a complete account of the small mammal fauna in the Kolyma region from 1915 to 1917. This discrepancy can largely be explained by the fact that Koren caught small mammals only in parts of the Kolyma region and not in those areas where the missing species are found in abundance.
 
Article
Tore Gjelsvik, former director of the Norwegian Polar Institute, died at the beginning of this year. He is fondly remembered by a great many people. In this piece, Olav Orheim recalls the man and his key role in Norwegian polar activities. Orheim was head of Antarctic Research at the Norwegian Polar Institute in 1972–1993 and was the institute's director from 1993 to 2005.
 
Article
Seasonal variations of iceberg distribution in the Barents Sea have been studied on the basis of Russian observations for the period 1933-1990. The maximum southern distribution is observed in January and the minimum in September and October. A significant correlation coefficient of 0.5 is calculated for the relationship between the latitude of the southern ice cover expansion and the corresponding expansion of iceberg distribution. There is a general temporal trend of increased southern locations of iceberg observations during the period considered. Some analyses of iceberg dimensions in the western part of the Barents Sea are based on observations obtained in 1988–1990 under the Ice Data Acquisition Programme (IDAP) and under the Soviet-Norwegian Occanographic Programme (SNOP).
 
Article
Recently observed changes in the Arctic have highlighted the need for a better understanding of Arctic dynamics. This research addresses that need and is also motivated by the recent finding of two regimes of Arctic ice - ocean wind-driven circulation. In this paper, we demonstrate that during 1946-1997 the Arctic environmental parameters have oscillated with a period of 10-15 years. Our results reveal significant differences among atmosphere, ice, and ocean processes during the anticyclonic and cyclonic regimes in the Arctic Ocean and its marginal seas. The oscillating behaviour of the Arctic Ocean we call the Arctic Ocean Oscillation (AOO). Based on existing data and results of numerical experiments, we conclude that during the anticyclonic circulation regime the prevailing processes lead to increases in atmospheric pressure, in ice concentration and ice thickness, river runoff, and surface water salinity - as well as to decreases in air temperature, wind speed, number of storms, precipitation, permafrost temperatures, coastal sea level, and surface water temperature. During the cyclonic circulation regime the prevailing processes lead to increased air and water temperatures, wind speed, number of storms,open water periods, and to decreases in ice thickness and ice concentration, river runoff, atmospheric pressure, and water salinity. The two-climate regime theory may help answer questions related to observed decadal variability of the Arctic Ocean and to reconcile the different conclusions among scientists who have analysed Arctic data obtained during different climate states.
 
Article
A simple model using upper-air meteorological variables in the NCEP-NCAR Reanalysis database is used to model seasonal components of mass balance of three glaciers in Svalbard. The model was originally developed for glaciers in North America, and has been applied to glaciers in Norway, Sweden and Iceland. Over the period for which mass balance data are available for the three Svalbard glaciers, the model fit yields r 2 values ranging from 0.46 to 0.61 for winter balance Bw and from 0.56 to 0.59 for summer balance Bs. Sensitivity to +1°C warming was about −0.36 m yr−1 water equivalent (w.eq.), caused mainly by increased ablation and secondarily by shift of precipitation from snow to rain. Sensitivity to a 10% increase in precipitation was about +0.06 m yr−1 w.eq. The model, calibrated over the period of observations, was used to extend the mass balance series back to 1948. At annual resolution, observed mass balance of the three glaciers correlates poorly with both the North Atlantic Oscillation (NAO) and with glaciers in Norway. Over two multiyear periods, the strongly positive NAO period 1990–1996 and the period afterward, glaciers in both Svalbard and especially Norway showed a pronounced decline in Bw. However, Bs for Svalbard glaciers was not more strongly negative after 1996, in contrast to glaciers in Norway.
 
Article
A hindcast simulation of the Arctic and Antarctic sea ice variability during 1955-2001 has been performed with a global, coarse resolution ice-ocean model driven by the National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis daily surface air temperatures and winds. Both the mean state and variability of the ice packs over the satellite observing period are reasonably well reproduced by the model. Over the 47-year period, the simulated ice area (defined as the total ice-covered oceanic area) in each hemisphere experiences large decadal variability together with a decreasing trend of Ø1% per decade. In the Southern Hemisphere, this trend is mostly caused by an abrupt retreat of the ice cover during the second half of the 1970s and the beginning of the 1980s. The modelled ice volume also exhibits pronounced decadal variability, especially in the Northern Hemisphere. Besides these fluctuations, we detected a downward trend in Arctic ice volume of 1.8% per decade and an upward trend in Antarctic ice volume of 1.5% per decade. However, caution must be exercised when interpreting these trends because of the shortness of the simulation and the strong decadal variations. Furthermore, sensitivity experiments have revealed that the trend in Antarctic ice volume is model-dependent.
 
The structure of the HBV model.
Illustrated development of the glacial melt coefficient, f ice .
Simulated and observed glacial mass balance.
Optimal parameter values used in the model compared to values found in the literature.
Article
An energy balance based HBV model was calibrated to the run-off from Bayelva catchment in western Spitsbergen, Svalbard. The model simulated the glacier mass balance, and the results were compared to observations at Austre Brøggerbreen for the period 1971-1997. Even though the model was optimized to observed run-off from a catchment in which the glaciers constitute 50% of the area, and not to the observation of glacier mass balance, the model was able to reconstruct the trends and values of the mass balance found through observations. On average the simulation gave a negative net balance of 696 mm. The observed average is 442 mm. The simulated winter accumulation was in average for the same period 9% lower and the summer ablation 17% higher than the observed. The years 1994-96 show deviations between simulated and observed winter accumulation up to 160%. This can probably be accounted for by extreme rainfall during the winter, leading to thick ice layers which make accurate observations difficult. The higher simulated summer ablation might indicate that the glaciers in the catchment as a whole have a larger negative mass balance than Austre Brøggerbreen. The simulations showed that the glacier mass-balance would be in equilibrium with a summer temperature 1.2°C lower than the average over the last decades or with a 100% increase in the winter (snow) precipitation. These are higher values than former estimates. A combined change of temperature and precipitation showed a synergic effect and thereby less extreme values.
 
Article
Diagnostic computations of density-driven circulation for seven winters from 1973 through 1979 were carried out. The only forcing was provided by observed temperature and salinity data collected during onsite Russian winter surveys in 1973–79. Computed circulations from 1973 through 1978 were close to the mean circulation obtained earlier by averaging observed 1973–79 temperature and salinity (Polyakov & Timokhov 1994). The computed 1979 density-driven circulation flowed counter-clockwise to the north of the Laptev Sea. This circulation pattern was caused by an anomalous salinity distribution associated with changes in the atmospheric circulation regime in 1979. Prevailing offshore winds blew fresh water from the Laptev and East Siberian shelves toward Fram Strait. Fresh water was exchanged for saltier intermediate water that upwelled to the surface along the slope. The observed surface salinity anomalies at the continental slope of the Laptev Sea in 1979 increased by several salinity units. One may speculate that the same process may have caused the observed salinification of the Eurasian Basin in the 1990s.
 
Article
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.
 
Article
For ease in discerning an Antarctic circumpolar wave in the perimeter of the ice pack, we construct a time series of the sea ice extents (essentially the area within the ice perimeter) in 1-degree longitudinal sectors for the period 1978–1996, as observed with the multichannel microwave imagers on board the NASA Nimbus 7 and the DOD (Dept. of Defense) DMSP (Defense Meteorological Satellite Program) F8. F11, and F13 satellites. After converting the time series into complex numbers by means of a Hilbert transform, we decompose the time series of the 360 sectors into its complex principal components (CPCs), effectively separating the spatial and temporal values. Then we decompose the real and imaginary parts of the temporal portions of the first three CPCs (complex principal compenents) by Empirical Mode Decomposition into their intrinsic modes, each representing a narrow frequency band, resulting in a collection of three CPCs for each intrinsic mode. Finally, we reconstruct the data in two different ways. First, we low-pass filter the data by combining all of the intrinsic modes of each CPC with periods longer than two years, which we designate as low-pass filtered. Next, we select the intrinsic mode of each CPC with periods of approximately four years, which we designate the quasiquadrennial (QQ) modes. The low-pass filtered time series shows eastward propagating azimuthal motion in the Ross and Weddell Seas, but no clearly circumpolar motion. The QQ time series, on the other hand, clearly shows castward propagating circumpolar waves, but with occasional retrograde motion to the west.
 
Article
Hydrographic and current measurements obtained during the Norwegian Antarctic Research Expedition 1978/79 to the southern Weddell Sea are presented. Cold, dense Ice Shelf Water circulating under the floating ice shelves is observed to leave the shelf as a concentrated bottom flow. From moored current metres this discharge is estimated at 0.7 106 m3/s at -2.0°C (one year average) and with no appreciable seasonal variation. This contribution to the Weddell Sea Bottom Water is clearly identified through extreme temperature gradients at our deepest stations (below 2500 m). The core of Weddell Deep Water shows a considerable (T ∼ 0.5°C) warming up since 1977, presumably due to the lack of polynya activity in the intervening period. Measurements in the coastal current at the ice shelf (70°S, 2°W) show step structures which are probably due to cooling and melting at the vertical ice barrier. Slight supercooling due to circulation under the ice shelf is also seen. The net effect of the ice shelf boundary seems to be a deep reaching cooling and freshening of the coastal current providing the low salinity, freezing point Eastern Shelf Water. This process is considered a preconditioning which enhances production of the saline Western Shelf Water which in turn is transformed to Ice Shelf Water.
 
Article
To evaluate improvements in modelling Arctic sea ice, we compare results from two regional models at 1/12° horizontal resolution. The first is a coupled ice-ocean model of the Arctic Ocean, consisting of an ocean model (adapted from the Parallel Ocean Program, Los Alamos National Laboratory [LANL]) and the “old” sea ice model. The second model uses the same grid but consists of an improved “new” sea ice model (LANL/CICE) with a simple ocean mixed layer. Both models are forced with European Centre for Medium-range Weather Forecasts reanalysis data for 1979–1993. A comparison of the two sea ice models focuses on the winter of 1987 to emphasize the internal ice stress and to minimize biases towards a particular Arctic climate regime. The “new” sea ice model gives improved ice deformation and drift fields. These improvements are associated at least in part with the multi-category representation of the ice thickness distribution and more realistic parameterization of the ice strength. Long, narrow features in ice divergence and shear fields resemble those observed in SAR imagery, except that their average width is overestimated, possibly due to insufficient horizontal resolution. We also compare the mean sea ice drift and its decadal variability in two “old” sea ice models at different horizontal resolutions: 18-km and 9-km. We find no significant change in ice drift between the two models, except in areas of significant ice-ocean interactions due to more realistic ocean currents and water mass properties in the 9-km model.
 
Article
A survey on the Common Eider Somateria mollissima in wing-feather moult and females with young was carried out in connection with Norsk Polarinstitutt's expedition to Svalbard in July and August 1979. A total of 3450 moulting eider were found on a water area of approximately 2500 km2; 18% of these were flightless. Females dominated in the population with about 82%. Of the breeding population, 109 females with 336 young were found. The average ratio of female to young has been calculated at 1:3.08. This ratio in relation to other studies of eider productivity is discussed briefly.
 
Article
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.
 
Article
Journal publications on Antarctic science were analysed for a period of 25 years (1980–2004) through a set of scientometrics and network analysis techniques. The study is based on 10 942 records (research articles, review articles, letters, etc.) with the word fragment “antarc*” in the title published in 961 international, peer-reviewed journals and retrieved from Thomson Scientific’s Science Citation Index database. During the period under investigation, productivity increased threefold and there was a 13-fold increase in journal publications co-written by authors from different countries. The five nations with the highest output were the USA (with 26.7% of the total output), the UK (13.8%), Australia (9.7%), Germany (8.8%) and Italy (6.0%). The top five institutions in terms of journal publications were the British Antarctic Survey (972 publications), the Alfred Wegener Institute of Polar and Marine Research, Germany (475), the Australian Antarctic Division (312), the University of Tasmania, Australia (305), and the National Aeronautics and Space Administration, USA (293).
 
Article
we have obtained one year of measurements from a subsurface instrumented mooring carrying two current meters and one bottom pressure recorder in the strait between Nordaustlandet and Kvitøya in the northeastern Svalbard archipelago. The observations show a mixed tide with typical amplitudes 0.4 db and 10cm sec−1. The semidiurnal tide is characterized by a progressive wave propagating toward the south. together with a cross-channel baroclinic mode. The annual average (non-tidal) current is less than 2cm sec−1 toward the north-east, suggesting that the transport into the Arctic Ocean is approximately 0.2 × 106m3s−1.
 
Article
Just after World War II the size of the Northeast Arctic cod (Gadus morhua) stock was about 6 million tonnes, but at the beginning of the 1980s the stock had been reduced to 1 million tonnes, due mainly to the excessively high fishing-mortality. Nevertheless, the stock produced strong year classes at the 0-group stage in the relatively warm period 1983-1985. At the same time, individual growth in the cod stock was good, and in 1986 the stock size increased to over 1.5 million tonnes.However, the cod preyed increasingly on the capelin (Mallotus villosus) present, and by the end of 1986 the capelin stock was seriously depleted. The cod compensated for the loss of capelin by preying more intensively on other food items, including smaller cod. Cannibalism increased by a factor of three from 1984 to 1986, and this is one important reason why the 1984 and 1985 year classes did not recruit to the fisheries as expected. Individual growth was dramatically reduced, and the average fish weight decreased by about 50% in most age groups. Because the quotas are in tonnes, more fish than expected were caught. This resulted in serious management problems and led to reductions both in stock size and quotas compared to the optimistic prognosis of the mid-1980s.
 
Article
The hydrographic (CTD) observations and pendulum current measurements obtained with M/S ‘Lance’ in August 1981 in the area west and north of Spitsbergen, are presented. The warm and saline northward flow, known as the West Spitsbergen Current, is found to follow the shelf break. In the Fram Strait the hydrographic structure is complicated because of eddies and other transient movements. The current measurements suggest a two-layer structure where the velocity vector rotates in opposite directions in the two layers with a period near the semidiurnal tidal period.
 
Article
Hydrographic (CTD) observations obtained with R/V‘Lance’in July-August 1982 across the Fram Strait are presented. The extent and the presence of traditional water masses such as Atlantic Water, Polar Water and Greenland Sea Deep Water are discussed. The complicated hydrographical structure in the upper water masses due to eddies and fronts near the ice edge is noted. An intermediate water mass characterized by a salinity minimum is found all across the Strait, and is suggested to originate in the Greenland Sea. The deep water in the south-west part of the Strait shows strong horizontal salinity and temperature gradients, and the structure of the corresponding station profiles indicates large hydrographical activity. This is in contrast to the east-north-east part, where the horizontal gradients are much weaker and the profiles much smoother. Thus most of the deep-and bottom-water communication between the Greenland/ Norwegian Seas and the Arctic Ocean seems to take place west of the 0° meridian.
 
Article
The pelagic distributions of seabirds in the Greenland, Norwegian and western Barents Seas are poorly known, especially in winter. This paper describes quantitative observations made in the course of an oceanographic cruise between 60°-79°13′N and 15°W-18°30′E from 25 February to 4 April 1982. Seabirds were generally scarce: the principal species were Fulmarus glacialis, Rissa tridactyla, Pagophila eburnea, Una spp. and Alle atle. Numbers were greatest in the south and east, where the sea surface temperatures were warmest. Pagophila eburnea and Cepphus grylle were most commonly seen near the edge of the pack-ice in the Greenland Sea. In the pack-ice zone Fulmarus glacialis and Alle alle were commonest where the sea surface was 40–60% covered with ice. These late-winter observations are compared with published accounts of summer distributions. Preliminary quantitative comparisons also suggest that the size of the population of Uria spp. wintering in the survey area, and especially in the western Barents Sea, is significantly larger than that which winters off Nova Scotia, eastern Canada; the reverse is true of Alle alle. R. G. B. Brown, Canadian Wildlife Service, Bedford Institute of Oceanography, P.O. Boxlø06, Dartmouth, Nova Scotia, Canada, B2Y 4A2.
 
Article
As in previous years Norsk Polarinstitutt has carried out mass balance investigations on Storbreen and Hardangerjøkulen in mainland Norway and on Broggerbreen and Lovenbreen in Svalbard. More than 20 years of measurements show that the glaciers both in mainland Norway and in Svalbard are retreating.Both in 1985 and in 1986 the glaciers in Norway had a negative net balance. At Storbreen the mean annual net balance value 1949-86 is -0.30 m in water equivalents, while on Hardangerjflkulen the mean value 1963-86 is -0.02 m.The two glaciers measured in Svalbard also had negative net balance in 1985 and in 1986. Both measured glaciers have had negative balance nearly all years since the measurements started in 1966. The mean value is close to -40g/cm2 or -0.4 m on both.
 
Article
The distribution of capelin was mapped in the area east of Hopen. Zooplankton was sampled with Juday net and 1 m2 MOCNESS sampler, and analysed with respect to hydrography and capelin abundance. The capelin “front” coincided more or less with the physical Polar Front, and this complicated the interpretation of the results. Strong indications for a grazing impact by capelin on zooplankton were nevertheless obtained. The zooplankton biomass was significantly lower in the area with high abundance of capelin than in the area with no capelin. This effect was due to a lower biomass of relatively large zooplankton (> 1 mm size fraction) and seen most clearly in data obtained with the MOCNESS. The biomass of zooplankton in the upper 100 m was very low where capelin was present, suggesting rapid depletion of the major prey items. The biomass (m −2) of capelin in the capelin front area was about three times higher than the biomass of zooplankton in areas without capelin. The capelin front would therefore have the potential to graze down the available prey in 3-4 days. Light seems to be an important factor for the predation impact by capelin, resulting in strong interactions between capelin predation and zooplankton vertical distribution.
 
Article
Storbreen in southern Norway has been measured continuously since 1949. The mean specific net balance -0.29 m water equivalents. In 1987, however, the net balance was 0.32 m, which is the highest surplus in twenty years. The results of the whole period are given in Table 1In Svalbard the summer of 1987 was unusually cold, which resulted in the first year with positive net balance on Brøggerbreen and Lovénbreen since the measurements started in 1968, The net balance was 0.22 m and 0.24 m, respectively, while the average is -0.43 m and -0.34 m.Measurements at Kongsvegen in the inner part of Kongsfjorden started in 1987. The work was concentrated along the central flow line. The result was a positive net balance of 0.50 m.
 
Article
Sampling of airborne pollen and spores at Ny-Alesund on Spitsbergen in the summer of 1986, by means of a Burkard pollen and spore trap, revealed only very low concentrations of air spora: a cumulative diurnal mean for the whole season of less than 200 pollen grains and just in excess of 9,000 moss and fungal spores. The most frequent pollen types recorded were those of the local taxa: Saxifraga, Salix and Oxyria digyna, whereas the share of pollen of exotic taxa, Betula, Pinus, Juniperus and Alnus, contributed only 9% of the total pollen sum. Back trajectories and pollen registrations at various aerobiological stations in Scandinavia designate central Finland as a possible source area both for the Betula and Pinus pollen. The maximum diurnal mean concentration of Cladosporium was merely 40 spores per m3 air. One may assert that the air at Ny-Alesund is almost free from allergenic pollen and spore types.
 
Article
The distribution of Brünnich's Guillemot in ice covered waters and near the marginal ice zone in the southern part of the Barents Sea was mapped from ship and helicopter in February/March 1987. High densities of Brünnich's Guillemot (up to 1,300 ind./km2) were found in ice leads. The density of birds was especially high over shallow banks where the sea depth was 40-80 m.A diel movement was also recorded. In the evening the birds left the leads and flew south. Next morning they returned to feed in the open leads. How far they migrated is uncertain, but possibly they flew down to the open sea or to leads close to the marginal ice zone. The migration may have been a means of avoiding to become trapped if leads closed after dark.
 
Article
During the summer 1987 expedition of the polar research vessel‘Polarstern’in the Eurasian Basin of the Arctic Ocean, sea ice at about 84-86°N and 20-30°E was found to have high concentrations of particulate material. The particle-laden ice occurred in patches which often darkened more than half the ice surface at our northernmost positions. Much of this ice appeared to be within the Siberian Branch of the Transpolar Drift stream, which transports deformed, multi-year ice from the Siberian shelves westward across the Eurasian Basin. Lithogenic sediment, which is the major component of the particulate material, may have been incorporated during ice formation on the shallow Siberian seas. Diatoms collected from the particle-rich ice surfaces support this conclusion, as assemblages were dominated by a marine benthic species similar to that reported from sea ice off the coast of northeast Siberia. Based on drift trajectories of buoys deployed on the ice it appears that much of the particle-laden ice exited the Arctic Ocean through the Fram Strait and joined the East Greenland Current.Very different sea ice characteristics were found east of the Yermak Plateau and north of Svalbard and Frans Josef Land up to about 83-84°N. Here sea ice was thinner, less deformed, with lower amounts of lithogenic sediment and diatoms. The diatom assemblage was dominated by planktonic freshwater species. Trajectories of buoys deployed on sea ice in this region indicated a tendency for southward transport to the Yermak Plateau or into the Barents Sea.
 
Article
Large concentrations of Little Auks were recorded off central Norway in March and April 1988. Their pelagic distributional patterns may be related to the frontal system between Atlantic water and the coastal stream off central Norway. Peak densities of more than 1,000 Little Auks per km2 were recorded in two areas on the continental shelf, close to the frontal system. These densities were up to 500 times as high as those found in adjacent areas. A change in distribution with season was observed, suggesting a seasonal association with the front.
 
Article
Examination of 17 samples collected by a 20 μm meshed meshed net in Kongsfjorden, Svalbard, 8–19 July 1988, showed a dominance of dinoflagellates and the chrysophyte Dinobryon Balticum in the surface layers, whereas the diatom and the haptophyte Phaecystis pouchetii abundance increased with depth. The diatom Pseudo-nitzschia granii appeared together with P. pouchetii through the whole water column, and Actinocyclus curvatulus was one of the few diatoms present also in the surface samples. Two samples, from 15 and 50 m, respectively, were cleaned of organic material and mounted in Naphrax for a more critical identification of the diatoms. We were able to group the species according to habitats, especially types of ice. The planktonic Thalassiosira antarctica var. borealis, T. hyalina, T. nordenskioeldii, Bacterosira bathyomphaia, Chaetoceros furcellatus, C. socialis and Fragilariopsis oceanica were present mainly as resting stages representing a post-bloom situation. These species and T. gravida appear early in the season and may have started to grow already under the ice. Fragilariopsis cylindrus and F. oceanica seem to have a closer affinity to ice than Thalassiosira and Chaetoceros spp. although they are common in the plankton. Some Nitzschia species which are usually regarded as typical sea-ice diatoms and have thicker and older ice as the main habitat were present only in small cell numbers in the plankton samples. The last component, evidently introduced from Atlantic water in the Norwegian Sea, consisted of diatoms with a more oceanic distribution, e. g. Fragilariopsis pseudonana and a small form of Thalassiosira bioculata.
 
Article
Ship-based surveys of seabirds were carried out off southwestern Greenland in the autumn of 1988 and winter of 1989. The results provide the first quantitative information on seabird distribution and numbers for single seasons and estimates for one particular area in winter. Some oceanographic habitat characteristics important for seabird distribution are described. In winter, high numbers of king eiders Somaleriaspectabilis, Brünnich's guillemots Urialomvia, glaucous gulls Larushyperboreus, Iceland gulls Larusglaucoides, great black-backed gulls Larusmarinus and black guillemots Cepphusgrylle were found in offshore habitats with heavy ice cover. An estimated 280,000 king eiders, 170,000 Brünnich's guillemots, 2,500 glaucous gulls, 7,000 Iceland gulls, 9,500 great black-backed gulls and 25,000 black guillemots were found in winter in an area west of Nuuk.
 
Article
Goose populations, with special emphasis on Light-bellied Brent Geese Branta bernicla hrota, were censured in Tusenøyane and Tjuvfjorden, southeast Svalbard, July-August 1989. A total of 425 non-breeding Brent Geese, 210 Barnacle Geese Branta leucopsis and 421 Pink-footed Geese Anser bra-chyrhynchus and 11, 2 and 3 families of the three species, respectively, were counted. Brent Geese attempted to nest on 6 of the 20 islands surveyed, and were successful on four. Barnacle Geese attempted to nest on three islands and were successful on two. Many islands known to be traditional nesting sites were entirely void of geese. Pink-footed Geese were only seen in Tjuvfjorden. The breeding failure on the islands was linked to the presence of the Arctic Fox Alopex lagopus which probably caused the geese to completely give up the attempt to nest. On one island the fox had apparently arrived after nest initiation and ravaged 45 Brent Goose and Barnacle Goose nests. It is likely that the foxes stranded on the islands during ice break-up. As a consequence of the presence of foxes on most of Tusenøyane, more than half of the potential breeding segment of the Svalbard Brent Goose population failed to nest in the summer of 1989.
 
Article
The nutrient status of the various water mass structures within a large sampling grid around Elephant Island are reported and the nutrient concentrations relative to jata from the physical and biological components of the Antarctic Marine Living Resources Programme are discussed. Concentrations of silicic acid, nitrate and phosphate (Si/N/P) were measured in the upper water column during January-March of three successive years. Samples were taken from eleven depths at 17 stations in 1991, and at four depths at 144 stations in 1992 and 182 stations in 1993. There was considerable variability in the concentrations of all three nutrients within the study area, but silicic acid showed the greatest variance among the water masses present in the sampling grid. The ratios (Si/N/P) of the nutrient deficits (difference in winter and summer values) in the upper 100 m differed considerably in Drake Passage waters as compared to Bransfield Strait waters, with both nitrate and silicic acid showing the greatest variance. Nutrient deficits did not increase from January to February, indicating that rates of replenishment of nutrients to the euphotic zone by physical processes and/or biological regeneration were approximately equal to the rate of uptake and assimilation by phytoplankton during that time period. The seasonal deficits, however, were substantial. Estimates of daily rates of primary production based on these nutrient deficits were comparable to the rates as measured by radiocarbon for Drake Passage waters, but much smaller for Bransfield Strait waters.
 
Article
A time series of ERS-1 SAR images is used to estimate ice drift in the Fram Strait January-March 1992 (the ERS-1 mission first ice phase). The images all cover the same area. The sampling interval is three days. The paper shows examples of estimation of ice drift and divergence from this image time series. Divergence is an important quantity in order to estimate ice production and hence mixing of the ocean water masses.A reference configuration of ice points is defined for each image. These ice points are identified in the successive image giving a set of point pairs. These point pairs are input for statistical analysis.Upward looking sonars (ULS) and current meters are moored below the scene. A combination of the SAR derived dynamics and the ULS derived ice thickness series will give opportunities to estimate ice mass flux into the Greenland Sea, and to improve ice classification algorithms.
 
Instruments and deployment depths.
Weekly mean currents from the three years of measurements. These values are not fi ltered or detided in any way.
Time series of daily mean ice drafts. Both the mean draft (with open water) and the selective mean draft (excluding open water) are shown.
; the six strongest components are listed. A negative minor axis indicates clockwise rotation of the current ellipses. Inclinations are given in degrees counter-clockwise from east, while the phases are relative to Greenwich. The current parameters are the average of the three one-year time series from the current meters.
Article
From 1993 to 1996, three oceanographic moorings were deployed in the north-western Barents Sea, each with a current meter and an upward-looking sonar for measuring ice drafts. These yielded three years of currents and two years of ice draft measurements. An interannual variability of almost I m was measured in the average ice draft. Causes for this variability are explored, particularly its possible connection to changes in atmospheric circulation patterns. We found that the flow of Northern Barents Atlantic-derived Water and the transport of ice from the Central Arctic into the Barents Sea appears to be controlled by winds between Nordaustlandet and Franz Josef Land, which in turn may be influenced by larger-scale variations such as the Arctic Oscillation/North Atlantic Oscillation.
 
Top-cited authors
Marek Zajączkowski
  • Institute of Oceanology Polish Academy of Sciences
Jon Ove Hagen
  • University of Oslo
Christian Wiencke
  • Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research
Kai Bischof
  • Universität Bremen
Carlo Papucci